A crystalline stannyne

A crystalline stannyne | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article A crystalline stannyne Liu Leo Liu, Xin-Feng Wang, Chaopeng Hu, Jiancheng Li, Rui Wei, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-3050761/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 17 Jun, 2024 Read the published version in Nature Chemistry → Version 1 posted You are reading this latest preprint version Abstract The synthesis of heteronuclear alkyne analogs incorporating heavier group 14 elements (R 1 −C≡E−R 2 , E = Si, Ge, Sn, Pb) has posed a longstanding challenge, with no previous reports on isolable compounds of this nature. Until now, neutral silynes (R 1 −C≡Si(L)−R 2 ) and germynes (R 1 −C≡Ge(L)−R 2 ) stabilized by a Lewis base have achieved sufficient stability for structural characterization at low temperatures. Here we show the isolation of a base-free stannyne (R 1 −C≡Sn−R 2 ) at room temperature, achieved through the strategic use of a bulky cyclic phosphino ligand in combination with a bulky terphenyl substituent. Despite an allenic structure with strong delocalization of π-electrons, this compound exhibits adjacent ambiphilic carbon and tin centers, forming a unique carbon-tin multiple bond with ionic character. The stannyne demonstrates reactivity similar to carbenes or stannylenes, reacting with 1-adamantyl isocyanide and 2,3-dimethyl-1,3-butadiene. Additionally, its carbon-tin bond can be saturated by Et 3 N·HCl or cleaved by isopropyl isocyanate. Physical sciences/Chemistry/Coordination chemistry/Organometallic chemistry/Chemical bonding Physical sciences/Chemistry/Chemical synthesis/Reactive precursors Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Main Text Alkynes are ubiquitous organic compounds containing a carbon-carbon triple bond (Fig. 1a). They possess valuable versatility, participating in various reactions that lead to the formation of diverse functional groups and structures. 1 Consequently, alkynes play significant roles in both chemistry and biology. Substituting the carbon atoms involved in the triple bond of alkynes with heavier group 14 elements such as silicon, germanium, tin, and lead provides access to unique compounds known as heavier homonuclear alkyne analogs, namely disilyne, 2,3 digermyne, 4 distannyne, 5 and diplumyne 6 (R 1 −E≡E−R 2 , E = Si, Ge, Sn, Pb) (Fig. 1a). The groups led by Power, 4-6 Sekiguchi 2 and Wiberg 3 made significant contributions by isolating these compounds, opening up avenues for further exploration. 7-15 These compounds possess distinct characteristics compared to linear alkynes due to the second-order Jahn-Teller effect 16-19 observed in the heavier main group analogs. This effect leads to a slipped π-bond and substantial geometric distortion, providing a trans -bent molecular geometry. These unique electronic features render the heavier element centers ambiphilic, enabling them to display reactivity towards small molecules with strong enthalpic bonds. 7-11,20-23 By replacing one carbon atom in alkynes with a heavier group 14 element, their heteronuclear analogs are obtained: silyne, germyne, stannyne, and plumyne (R 1 −C≡E−R 2 , E = Si, Ge, Sn, Pb) (Fig. 1a). Theoretical predictions suggest that similar to R 1 −E≡E−R 2 , the R 1 −C≡E−R 2 compounds adopt a trans -bent molecular geometry. 24-30 However, without Lewis base stabilization, these compounds are completely unknown as isolable species. A major challenge in synthesizing R 1 −C≡E−R 2 is the energetically favored isomerization of R 1 −C≡E−R 2 into R 1 R 2 C=E, especially when R 1 and R 2 are small substituents. 24-30 Indeed, the isolation of these compounds as stable, isolable species has been a long-standing objective. As of now, the only neutral species proven to be sufficiently stable for structural characterization below –30 °C are silyne B 31 and two germynes C , 32 which were stabilized by a Lewis base, as reported by Kato and Baceiredo over a decade ago (Fig. 1b). It has been observed that they undergo intramolecular rearrangement reactions above this temperature threshold. 31,32 More recently, Kato isolated a base-stabilized cationic silyne D with moderate stability at room temperature (t 1/2 = 7 days in THF). 33 By contrast, stannyne and plumyne have not yet been identified as isolable species, even in the presence of a Lewis base for stabilization. Based on UV-vis spectroscopic observations, Kira and Sakamoto demonstrated the transient existence of stannyne F 34 during low-temperature photolysis of the corresponding diazo precursor (–196 °C). However, F is considered a highly transient species at room temperature, defying direct observation. 34,35 These findings underscore the inherent difficulty of isolating these highly reactive compounds under typical laboratory conditions. Landmark studies by Bertrand, 36 as well as more recent work by Kato, 31,32 Baceiredo, 31,32 and our group, 37,38 have showcased the remarkable potential of phosphinodiazomethyl anion salt as a versatile synthon for introducing a singlet carbyne anion (R−C – ) fragment to both main group and transition metal centers. This unique reactivity has led to the preparation of unusual species such as singlet carbene A and B - E (Fig. 1b). In our previous work, we isolated a copper phosphinocarbyne anion complex E by employing a bulky phosphino substituent. 38 Complementary computational studies conducted by Su have shed light on the properties of stannynes and suggested that appropriate bulky substituents can encapsulate the central C≡Sn unit, protecting it and enabling its isolation as a stable species. 29 Herein, we demonstrate the isolation of a base-free crystalline stannyne via the strategic combination of a bulky cyclic phosphino and a bulky terphenyl substituent. This species represents an example of a base-free heteronuclear analog of alkynes containing a heavier group 14 element, and it is also the unprecedented main group species to possess diverse adjacent ambiphilic centers. This work has significant implications for the future design of adjacent bis-ambiphile main group systems. Results and Discussion Synthesis and characterization In our pursuit of a stannyne, we aimed to introduce a π-donor substituent at the carbon center. This substitution has proven to effectively stabilize the singlet state of low-valent carbon species. 39,40 Additionally, increasing the steric bulk of the substituents at both carbon and tin atoms would provide desirable kinetic protection. 5 To achieve this goal, we synthesized a stannylenyl diazomethane 2 ( 31 P NMR: 125.5 ppm) as a precursor, bearing a bulky cyclic phosphino at the carbon center and a bulky terphenyl substituent at the tin center (Fig. 2). This compound was prepared by treating 1 37 with potassium tert -butoxide ( t BuOK) in THF followed by 2,6-Mes 2 C 6 H 3 SnCl 41 (Mes = mesityl) in the absence of light. The infrared absorption ν(CN 2 ) in 2 occurs at 1966 cm –1 , showing similarity to the corresponding absorption observed in metal-substituted phosphinodiazaomethanes. 37,38 Yellow single crystals of 2 were obtained by slowly evaporating its concentrated pentane solution at –30 ℃, and its structure was confirmed by X-ray diffraction (Fig. 3a). We observed an intriguing phenomenon whereby N 2 was gradually eliminated from a C 6 D 6 solution of 2 at room temperature over a period of approximately 7 hours (Supplementary Fig. S17). This elimination was concurrent with the intensity loss of the infrared ν(CN 2 ) absorption, affording species 3 . Alternatively, irradiating (303 nm) a solid of 2 at room temperature for 30 minutes followed by washing with cold pentane resulted in the isolation of 3 as a yellow solid with a 96% yield (217 mg, 0.254 mmol). The 31 P NMR resonance of 3 displays a singlet at 67.9 ppm accompanied by a satellite doublet arising from the P-Sn coupling (168.7 Hz). Meanwhile, its 119 Sn NMR signal shows a doublet at 1149.3 ppm (168.7 Hz). This stands in stark contrast to the spectroscopic characteristics of 2 , where no two-bond P-Sn coupling was observed and singlet resonances were detected in both the 31 P (125.3 ppm) and 119 Sn NMR (92.7 ppm) spectra. Surprisingly, we found that 3 was exceptionally stable in both its solid and solution states at room temperature and could be safely stored for several months in a glove box with a nitrogen atmosphere. However, it should be noted that 3 is sensitive to air and gradually decomposes into unknown substances in 1 h (Supplementary Fig. S22). The electronic spectrum of 3 reveals the presence of two broad absorption bands, ranging from 320 to 360 nm and 400 to 480 nm (Supplementary Fig. S60), which are responsible for its characteristic yellow color. Time-dependent density functional theory (TD-DFT) calculations indicate that these bands originate from HOMO to LUMO and HOMO–1 to LUMO transitions, respectively (Supplementary Fig. S71). Compound 3 crystalized as yellow crystals from a concentrated pentane solution at –30 ℃, and its X-ray diffraction analysis confirmed its formulation as [(CH 2 )(NDipp)] 2 PCSn(C 6 H 3 -2,6-Mes) (Dipp = 2,6-diisopropylphenyl; Mes = mesityl) (Fig. 3b). In contrast to the pyramidalization observed at P(1) in 2 (Fig.3a), the P(1) atom of 3 adopts a trigonal planar geometry with a sum of angles of 358.6°. Notably, the P(1)−C(1) bond in 3 is significantly shortened (1.561(6) Å) compared to that of 2 (1.879(8) Å), indicating strong P-to-C π-donation and resulting in multiple bond character. This is similar to observations in Bertrand’s (phosphino)(silyl)carbene Me 2 Si( t BuN) 2 PCSiMe 3 42 and our copper phosphinocarbyne anion complex [(CH 2 )(NDipp)] 2 PCCu(IPent) (IPent = 1,3-bis(2,6-di(3-pentyl)phenyl)imidazol-2-ylidene). 38 Additionally, the C(1)−Sn(1) bond length in 3 (2.082(6) Å) is shortened relative to 2 (2.134(8) Å) and lies between Pyykkö’s standard values for C−Sn single (2.15 Å) and double bonds (1.97 Å). 43 For comparison, the Sn(1)−C(2) bond length in 3 is 2.217(5) Å. These data indicate the presence of a multiple bond between C(1) and Sn(1) in 3 . The bond angles of P(1)−C(1)−Sn(1) (136.7(3)°) and C(1)−Sn(1)−C(2) (98.0(2)°) in 3 are slightly more acute than those in 2 (138.0(5) and 105.6(5)°, respectively). Computational studies We conducted quantum chemical calculations to elucidate the electronic structure of compound 3 . The optimized structural parameters of 3 obtained at the BP86-D3(BJ)/def2-TZVPP level of theory are in good agreement with the X-ray data (Supplementary Table 7). NBO analysis (BP86-D3(BJ)/def2-TZVPP) revealed that P(1) (1.59 a.u.) and Sn(1) (1.09 a.u.) atoms carry considerable positive charges, while C(1) (–1.45 a.u.) and C(2) (–0.39 a.u.) atoms are negatively charged. This charge separation is due to the lower electronegativity of phosphorus (2.19) and tin (1.96) compared to nitrogen (3.04) and carbon (2.55) elements. Furthermore, the Wiberg bond indexes (WBIs) of P(1)−C(1), C(1)−Sn(1), and Sn(1)−C(2) are 2.08, 0.80, and 0.60, respectively. These values indicate a pronounced multiple bond character for P(1)−C(1) and a relatively stronger bonding interaction between C(1) and Sn(1) than between Sn(1) and C(2). Notably, the WBI for the C(1)−Sn(1) bond in 3 (0.80) is slightly higher compared to those in 5 (0.77) and 6 (0.72) (vide infra) (Supplementary Table 8). This distinction can be attributed to the absence of a lone pair and a vacant 5p orbital at Sn(1) in 5 and 6 , which mitigates the extent of π-interaction with adjacent atoms (vide infra). It is important to acknowledge, however, that WBI values may not always precisely reflect the nature of multiple bonds, especially those with high ionic character, as exemplified by the relatively low WBI (0.89) of an Al−N triple bond in an iminoalane. 44 To gain further insights into the bonding situation of 3 , frontier molecular orbital (FMO), intrinsic bond orbital (IBO) 45,46 and electron localization function (ELF) 47 calculations were carried out (Fig. 4 and Supplementary Fig. S67). The HOMO (–4.47 eV) consists of the P(1)−C(1) π-bonding orbital and the lone pair orbital at Sn(1) (Fig. 4a). The HOMO–1 (–4.94 eV) corresponds to the P(1)−C(1)−Sn(1) out-of-plane 3-center-2-electron (3c2e) π-bonding orbital (Fig. 4b). Further, the HOMO–2 level, at –5.40 eV, is primarily composed of a slipped C(1)−Sn(1) π bond, exhibiting lone pair characteristics at both C(1) and Sn(1) (Fig. 4c). This form of slipped π bond contributes to the bent geometry observed at C(1) and is a feature commonly associated with heavier main group elements forming multiple bonds, 7-9 as seen in disilyne, 2 digermyne, 4 distannyne, 5 and diplumbyne. 6 Moreover, the LUMO (–2.01 eV) represents a C(1)−Sn(1) π*-antibonding orbital with a significant vacant 5p orbital character at Sn(1), along with the P−N σ*-antibonding orbitals (Fig. 4d). The LUMO+2 (–1.45 eV) features the P(1)−C(1) π*-antibonding orbital (Fig. 4e). Overall, this FMO analysis reveals the multiple bond character of the P(1)−C(1)−Sn(1) chain in 3 (see resonance forms in Fig. 2) and suggests that both C(1) and Sn(1) exhibit ambiphilicity. Notably, the ELF plot of 3 shows the ionic interaction between the C and Sn atoms in the P(1)−C(1)−Sn(1) plane, with limited electron density localized at the C(1)−Sn(1) and Sn(1)−C(2) bonds (Fig. 4f), whereas the P(1)−C(1) bond exhibits a strong covalent character. Our IBO analysis indicates that C(1) forms two σ bonds, one each with P(1) and Sn(1) ( IBO1 and IBO5 , Supplementary Fig. S67). Additionally, there is a slipped P(1)−C(1) π bond ( IBO2 ), arising from the donation of a lone pair by P(1). The lone pair on Sn(1) remains highly localized ( IBO4 ), while IBO3 illustrates a 3c2e π bond centered at C(1), consistent with the HOMO–1 of 3 . Natural resonance theory (NRT) calculations on a simplified model of 3 (where Dipp groups are replaced by H atoms and the Ter group by a CH 3 ), the predominant resonance form is identified as the allenic structure (26.65%) (Supplementary Figure S68). Other significant resonance forms include P(1)−C(1)=Sn(1) (11.02%) and P(1)−C(1)≡Sn(1) (5.35%), along with two forms of P(1)≡C(1)−Sn(1) contributing 10.33% and 7.67%, respectively. Taken together, these results, combined with the FMO and IBO findings, suggest that the electronic structure of 3 is most appropriately represented as an allenic structure 3A . This structure is characterized by considerable π-electron delocalization across the P(1)−C(1)−Sn(1) atoms, with P bearing a formal positive charge and Sn a negative charge. Despite an allenic structure of 3 , both NRT and FMO analyses (HOMO–1 and HOMO–2) suggest a minor contribution of the stannye form of P(1)−C(1)≡Sn(1). A salient structural characteristic of 3 is the near-perpendicular orientation of the N(1)−P(1)−N(2) plane to the P(1)−C(1)−Sn(1) plane (Fig. 3b). The trigonal-planar configuration of the phosphino moiety exhibits a pronounced twist relative to the P(1)−C(1)−Sn(1) plane, indicated by a torsion angle of –97.9(6)° for N(1)−P(1)−C(1)−Sn(1). Notably, this angle exceeds those reported for germmyne C , 32 which has a torsion angle of –73.6(6)°, and the methylenephosphonium salt [( i Pr 2 N) 2 P=C(TMS) 2 ][OTf], with a torsion angle of –59.5(3)°. 48 The distinct spatial configuration observed in 3 can be largely attributed to π-interactions. These interactions involve the lone pairs present on P(1) and Sn(1) and the formally unoccupied p orbital on C(1). Furthermore, the delocalization of the C(1) lone pair into the vacant p orbital of Sn(1) and into the N−P σ* antibonding orbitals plays a significant role (Supplementary Fig. S66). This type of out-of-plane negative hyperconjugation, emanating from the C(1) lone pair to the N−P σ* antibonding orbitals, is in line with stabilization approaches for a unique carbene with a σ 0 π 2 electronic configuration. 49 Upon performing a constrained geometry optimization, it has been determined that the alternative co-planar conformation is energetically disfavored by 4.2 kcal/mol relative to the experimentally observed structure of 3 (Supplementary Fig. S65). Reactivity Diarylstannylene with electron-withdrawing aryl substituents reacts with isocyanide, forming Lewis acid-base adducts. 50,51 However, treatment of 3 with 1-adamantyl isocyanide (AdNC) at room temperature yields the sole product 4 ( 31 P NMR: 112.2 ppm; 119 Sn NMR: 1486.9 ppm) (Fig. 5), regardless of the amount of AdNC used. Through multi-nuclear NMR and X-ray diffraction data, 4 is identified as a (phosphino)(stannylenyl)ketenimine with the stannylene center remaining intact (Fig. 6a). This reaction demonstrates the synthetic potential of stannynes for unique stannylenes with unconventional substituents. 52 The stannyne 3 not only functions as a carbene but also exhibits properties of stannylene. While the [4+1] cycloaddition of stannylenes with dienes is typically limited to stannylenes with electropositive substituents like germyl 53 and boryl, 54 the addition of excess 2,3-dimethyl-1,3-butadiene to a THF solution of 3 generates species 5 ( 31 P NMR: 3.7 ppm; 119 Sn NMR: –43.6 ppm) (Fig. 5). Isolation of 5 as colorless X-ray quality crystals in 65% yield confirms its formulation as a (phosphino)(stannyl)carbene (Fig. 6b). Contrasting with 3 , the phosphino group in 5 adopts a co-planar arrangement concerning the P(1)−C(1)−Sn(1) plane. This structural arrangement can be attributed to the absence of a lone pair and an unoccupied 5p orbital at Sn(1) in 5 . It is noteworthy that (phosphino)(stannyl)carbenes were previously considered reactive intermediates incapable of isolation, 55 making 5 the first example of its kind. This reaction highlights the versatility of stannynes as a versatile synthon for novel carbenes with unusual substituents. 40 To the best of our knowledge, 3 represents the first example of a main group compound with diverse adjacent ambiphilic centers. We then investigated the reactivity of the C(1)−Sn(1) multiple bonding character in 3 . When 3 was treated with dry HCl in dioxane, a complex mixture was observed. Nonetheless, addition reactions of 3 with excess Et 3 N·HCl at –35 o C, a mild Brønsted acid, proceeded smoothly, giving rise to the formation of 6 ( 31 P NMR: 111.3 ppm; 119 Sn NMR: –13.2 ppm). X-ray diffraction analysis confirmed that 6 is a double addition product, with two hydrogen atoms and two chlorine atoms attached to C(1) and Sn(1), respectively (Figure 6c). The C(1)−Sn(1) bond length in 6 elongates to 2.126(4) Å compared to 2.082(6) Å in 3 . By adjusting the reaction ratio of 3 :Et 3 N·HCl to 1:1, we observed the formation of 6 as well as a major intermediate ( 31 P NMR: 90.7 ppm), along with unreacted 3 (Supplementary Fig. S35). Although we were unable to isolate the intermediate, our calculations suggest that it is likely the monoaddition intermediate, specifically the stannaalkene [(CH 2 )(NDipp)] 2 PC(H)=Sn(Cl)(C 6 H 3 -2,6-Mes) (calc. 31 P NMR: 97.6 ppm, Supplementary Figure S72) (for a proposed mechanism, refer to Supplementary Fig. S61). In comparison, our experiments with a previous copper carbyne anion complex demonstrated that protonation of the [(CH 2 )(NDipp)] 2 PC – anion produced a transient monosubstituted carbene, spontaneously dimerizing into the alkene [(CH 2 )(NDipp)] 2 P(H)C=C(H)P[(NDipp)(CH 2 )] 2 . 38 However, when treating 3 with an equivalent of Et 3 N·HCl, the same alkene did not form, implying a minimal contribution from the stannyliumylidene resonance form (i.e. a complex of [(CH 2 )(NDipp)] 2 PC – anion and [(C 6 H 3 -2,6-Mes)Sn] + cation). Remarkably, 3 exhibited a facile reaction involving cleavage of the C−Sn bond when treated with isopropyl isocyanate ( i PrNCO) (Fig. 5). The reaction, conducted with either one or two equivalents of i PrNCO, predominantly produced 7 , while in the former case a portion of 3 remained unchanged. In the 31 P and 119 Sn NMR spectra of 7 , singlet resonances were observed at 15.7 and 342.9 ppm, respectively. To our surprise, single-crystal X-ray diffraction analysis of colorless crystals of 7 revealed complete splitting of the C−Sn bond through the formal insertion of two i PrNCO molecules, accompanied by rearrangement involving H- and O-shifts (Figure 6d) (for a proposed mechanism, refer to Supplementary Fig. S63). This O-migration bears resemblance to the rearrangement observed in phosphaketenes to phosphaheteroallenes. 56 Conclusion More than two decades after Power's groundbreaking work on distannyne 5 and a decade following the seminal contributions of Kato and Baceiredo in base-stabilized silyne and germyne, 31,32 the isolation of 3 stands as a testament to the feasibility of stabilizing base-free stannynes at room temperature. Compound 3 , featuring adjacent ambiphilic carbon and tin atoms, represents an unprecedented example of a main group species with such diverse ambiphilic centers. It showcases a carbon-tin multiple bond with ionic characteristics. Intriguingly, this stannyne can act as either a singlet carbene or a stannylene depending on the substrates involved, highlighting its versatility as a precursor for unique carbenes and stannylenes. Given the substantial impact of alkynes and their heavier homonuclear analogs across various disciplines, we believe that with continued development and research, their heteronuclear heavier counterparts will similarly find widespread applications in a variety of fields. Declarations Acknowledgement We gratefully acknowledge financial support from the National Natural Science Foundation of China (22350004; 22271132; 22101114), Shenzhen Science and Technology Innovation Program (JCYJ20220530114806015), Guangdong Innovation & Entrepreneurial Research Team Program (2021ZT09C278), and Guangdong Provincial Key Laboratory of Catalysis (2020B121201002). We also acknowledge the assistance of SUSTech Core Research Facilities. The theoretical work was supported by the Center for Computational Science and Engineering at SUSTech. Author contributions L.L.L. conceptualized and supervised the project. X.F.W. and R.W. performed the experimental work. L.L.L., X.F.W., C.H, and R.W. performed the computational work. X.F.W., C.P.H., J.C.L., R.W. and X.Z. performed the X-ray crystallographic analyses. L.L.L. wrote the paper with the input from all authors. All authors discussed the results in detail and commented on the paper. Competing interests The authors declare no competing interests. References Diederich, F. & Stang, P. J. Modern acetylene chemistry . (John Wiley & Sons, 2008). Sekiguchi, A., Kinjo, R. & Ichinohe, M. A stable compound containing a silicon-silicon triple bond. Science 305 , 1755-1757 (2004). Wiberg, N., Vasisht, S. K., Fischer, G. & Mayer, P. Disilynes. III [1] A relatively stable disilyne RSi≡SiR (R = SiMe(SitBu 3 ) 2 ). Z. Anorg. Allg. Chem. 630 , 1823-1828 (2004). Stender, M., Phillips, A. D., Wright, R. J. & Power, P. P. Synthesis and characterization of a digermanium analogue of an alkyne. Angew. Chem., Int. Ed. 41 , 1785-1787 (2002). Phillips, A. D., Wright, R. J., Olmstead, M. M. & Power, P. P. Synthesis and characterization of 2,6-Dipp 2 -H 3 C 6 SnSnC 6 H 3 -2,6-Dipp 2 (Dipp = C 6 H 3 -2,6-Pri 2 ): a tin analogue of an alkyne. J. Am. Chem. Soc. 124 , 5930-5931 (2002). Pu, L., Twamley, B. & Power, P. P. Synthesis and characterization of 2,6-Trip 2 H 3 C 6 PbPbC 6 H 3 -2,6-Trip 2 (Trip = C 6 H 2 -2,4,6-i-Pr 3 ): a stable heavier group 14 element analogue of an alkyne. J. Am. Chem. Soc. 122 , 3524-3525 (2000). Power, P. P. Main-group elements as transition metals. Nature 463 , 171-177 (2010). Fischer, R. C. & Power, P. P. π-Bonding and the lone pair effect in multiple bonds involving heavier main group elements: developments in the new millennium. Chem. Rev. 110 , 3877-3923 (2010). Power, P. P. An Update on multiple bonding between heavier main group elements: the importance of pauli repulsion, charge-shift character, and london dispersion force effects. Organometallics 39 , 4127-4138 (2020). Sekiguchi, A. Disilyne with a silicon-silicon triple bond: a new entry to multiple bond chemistry. Pure Appl. Chem. 80 , 447-457 (2008). Power, P. P. Silicon, germanium, tin and lead analogues of acetylenes. Chem. Commun. 38 , 2091-2101 (2003). Sugiyama, Y. et al. Synthesis and properties of a new kinetically stabilized digermyne: new insights for a germanium analogue of an alkyne. J. Am. Chem. Soc. 128 , 1023-1031 (2006). Lai, T. Y., Tao, L., Britt, R. D. & Power, P. P. Reversible Sn–Sn triple bond dissociation in a distannyne: support for charge-shift bonding character. J. Am. Chem. Soc. 141 , 12527-12530 (2019). Queen, J. D., Phung, A. C., Caputo, C. A., Fettinger, J. C. & Power, P. P. Metathetical exchange between metal–metal triple bonds. J. Am. Chem. Soc. 142 , 2233-2237 (2020). Ding, Y., Zhang, J., Li, Y. & Cui, C. Disilicon dicarbonyl complex: synthesis and protonation of CO with O–H bond. J. Am. Chem. Soc. 144 , 20566-20570 (2022). Bader, R. F. W. Vibrationally induced perturbations of molecular electron distribution. Can. J. Chem. 40 , 1164-1175 (1962). Pearson, R. G. Symmetry rule for predicting molecular structure and reactivity. J. Am. Chem. Soc. 91 , 1252-1254 (1969). Pearson, R. G. Concerning Jahn-Teller effects. Proc. Natl. Acad. Sci. U. S. A. 72 , 2104-2106 (1975). Grev, R. S. Structure and bonding in the parent hydrides and multiply bonded silicon and germanium compounds: from MHn to R 2 M=M'R 2 and RM≡M'R. Adv. Organomet. Chem. 33 , 125-170 (1991). Power, P. P. Interaction of multiple bonded and unsaturated heavier main group compounds with hydrogen, ammonia, olefins, and related molecules. Acc. Chem. Res. 44 , 627-637 (2011). Peng, Y., Ellis, B. D., Wang, X., Fettinger, J. C. & Power, P. P. Reversible reactions of ethylene with distannynes under ambient conditions. Science 325 , 1668-1670 (2009). Melen, R. L. Frontiers in molecular p-block chemistry: from structure to reactivity. Science 363 , 479-484 (2019). Spikes, G. H., Fettinger, J. C. & Power, P. P. Facile activation of dihydrogen by an unsaturated heavier main group compound. J. Am. Chem. Soc. 127 , 12232-12233 (2005). Apeloig, Y. & Karni, M. Triple bonds to silicon. Substituent effects on the thermodynamic and kinetic stabilities of silynes relative to their isomeric silylidenes and silavinylidenes. Organometallics 16 , 310-312 (1997). Danovich, D. et al. Silynes (RC≡SiR′) and disilynes (RSi≡SiR′): why are less bonds worth energetically more? Angew. Chem., Int. Ed. 40 , 4023-4026 (2001). Bibal, C., Mazières, S., Gornitzka, H. & Couret, C. A route to a germanium–carbon triple bond: first chemical evidence for a germyne. Angew. Chem., Int. Ed. 40 , 952-954 (2001). Wu, P.-C. & Su, M.-D. Theoretical designs for germaacetylene (RCGeR′): a new target for synthesis. Dalton Trans. 40 , 4253-4259 (2011). Ploshnik, E., Danovich, D., Hiberty, P. C. & Shaik, S. The nature of the idealized triple bonds between principal elements and the σ origins of trans-bent geometries—a valence bond study. J. Chem. Theory Comput. 7 , 955-968 (2011). Wu, P.-C. & Su, M.-D. Triply bonded stannaacetylene (RC≡SnR): theoretical designs and characterization. Inorg. Chem. 50 , 6814-6822 (2011). Wu, P.-C. & Su, M.-D. A new target for synthesis of triply bonded plumbacetylene (RC≡PbR): a theoretical design. Organometallics 30 , 3293-3301 (2011). Gau, D. et al. Synthesis and structure of a base-stabilized C-phosphino-Si-amino silyne. Angew. Chem., Int. Ed. 49 , 6585-6588 (2010). Berthe, J. et al. Synthesis and reactivity of a phosphine-stabilized monogermanium analogue of alkynes. J. Am. Chem. Soc. 133 , 15930-15933 (2011). Takahashi, S. et al. Base-stabilized cationic silyne with a π-accepting phosphonio substituent. Inorg. Chem. 62 , 6488-6498 (2023). Setaka, W., Hirai, K., Tomioka, H., Sakamoto, K. & Kira, M. Stannaacetylene (RSn⋮CR') showing carbene-like reaction mode. J. Am. Chem. Soc. 126 , 2696-2697 (2004). Setaka, W., Hirai, K., Tomioka, H., Sakamoto, K. & Kira, M. Formation of a stannylstannylenevia intramolecular carbene addition of a transient stannaacetylene (RSnCR′). Chem. Commun. 43 , 6558-6560 (2008). Igau, A., Grutzmacher, H., Baceiredo, A. & Bertrand, G. Analogous α,α'-bis-carbenoid, triply bonded species: synthesis of a stable γ3-phosphino carbene-γ5-phosphaacetylene. J. Am. Chem. Soc. 110 , 6463-6466 (1988). Hu, C. et al. Crystalline monometal-substituted free carbenes. Chem 8 , 2278-2289 (2022). Wei, R., Wang, X.-F., Hu, C. & Liu, L. L. Synthesis and reactivity of copper carbyne anion complexes. Nat. Synth. 2 , 357-363 (2023). Bourissou, D., Guerret, O., Gabbaï, F. P. & Bertrand, G. Stable Carbenes. Chem. Rev. 100 , 39-92 (2000). Vignolle, J., Cattoën, X. & Bourissou, D. Stable noncyclic singlet carbenes. Chem. Rev. 109 , 3333-3384 (2009). Simons, R. S., Pu, L., Olmstead, M. M. & Power, P. P. Synthesis and characterization of the monomeric diaryls M{C 6 H 3 -2,6-Mes 2 } 2 (M = Ge, Sn, or Pb; Mes = 2,4,6-Me 3 C 6 H 2 −) and dimeric aryl−metal chlorides [M(Cl){C 6 H 3 -2,6-Mes 2 }] 2 (M = Ge or Sn). Organometallics 16 , 1920-1925 (1997). Kato, T., Gornitzka, H., Baceiredo, A., Savin, A. & Bertrand, G. On the electronic structure of (phosphino)(silyl)carbenes: single-crystal X-ray diffraction and ELF analyses. J. Am. Chem. Soc. 122 , 998-999 (2000). Pyykkö, P. & Atsumi, M. Molecular double-bond covalent radii for elements Li–E112. Chem. Eur. J. 15 , 12770-12779 (2009). Queen, J. D., Irvankoski, S., Fettinger, J. C., Tuononen, H. M. & Power, P. P. A monomeric aluminum imide (iminoalane) with Al–N triple-bonding: bonding analysis and dispersion energy stabilization. J. Am. Chem. Soc. 143 , 6351-6356 (2021). Klein, J. E. M. N. & Knizia, G. cPCET versus HAT: A direct theoretical method for distinguishing X–H bond-activation mechanisms. Angew. Chem., Int. Ed. 57 , 11913-11917 (2018). Knizia, G. Intrinsic Atomic Orbitals: An unbiased bridge between quantum theory and chemical concepts. J. Chem. Theory Comput. 9 , 4834-4843 (2013). Savin, A., Nesper, R., Wengert, S. & Fässler, T. F. ELF: the electron localization function. Angew. Chem. Int. Ed. Engl. 36 , 1808-1832 (1997). Igau, A., Baceiredo, A., Gruetzmacher, H., Pritzkow, H. & Bertrand, G. Synthesis, reactivity, and crystal structure of the first methylenephosphonium ion: a severely twisted valence isoelectronic olefin. J. Am. Chem. Soc. 111 , 6853-6854 (1989). Hu, C., Wang, X.-F., Li, J., Chang, X.-Y. & Liu, L. L. A stable rhodium-coordinated carbene with a σ 0 π 2 electronic configuration. Science 383 , 81-85 (2024). Grützmacher, H., Freitag, S., Herbst-Irmer, R. & Sheldrick, G. S. Investigations of the structure and reactivity of a stannaketenimine. Angew. Chem. Int. Ed. Engl. 31 , 437-438 (1992). Mansikkamäki, A., Power, P. P. & Tuononen, H. M. Computational analysis of n→π* back-bonding in metallylene–isocyanide complexes R 2 MCNR′ (M = Si, Ge, Sn; R = tBu, Ph; R′ = Me, tBu, Ph). Organometallics 32 , 6690-6700 (2013). Mizuhata, Y., Sasamori, T. & Tokitoh, N. Stable heavier carbene analogues. Chem. Rev. 109 , 3479-3511 (2009). Setaka, W., Sakamoto, K., Kira, M. & Power, P. P. Synthesis and structure of stable tri-tert-butylgermyl-substituted stannylene and germylene. Organometallics 20 , 4460-4462 (2001). Protchenko, A. V. et al. Enabling and probing oxidative addition and reductive elimination at a group 14 metal center: cleavage and functionalization of E–H bonds by a bis(boryl)stannylene. J. Am. Chem. Soc. 138 , 4555-4564 (2016). Emig, N., Tejeda, J., Réau, R. & Bertrand, G. The surprising instability of (phosphino)(stannyl)carbenes! Tetrahedron Lett. 36 , 4231-4234 (1995). Li, Z. et al. N-Heterocyclic carbenes as promotors for the rearrangement of phosphaketenes to phosphaheteroallenes: A case study for OCP to OPC constitutional isomerism. Angew. Chem., Int. Ed. 55 , 6018-6022 (2016). Methods Experimental details Synthetic methods. All manipulations were conducted within a nitrogen-filled glovebox or under a dry nitrogen atmosphere, employing standard Schlenk techniques, unless otherwise specified. Toluene, n -hexane, n -pentane, and tetrahydrofuran were subjected to distillation over sodium or LiAlH 4 and subsequently stored over activated molecular sieves in the glove box. Commercial reagents were obtained from Energy Chemical, J&K, or TCI Chemical Co. and were used without further purification. The reagents 1 37 and 2,6-Mes 2 C 6 H 3 SnCl 41 were prepared according to the reported literature. Note: Although we have not experienced any problems, cautions should be exercised when handling diazo reagents due to their potentially explosive nature, especially for large scale reactions. Spectroscopic methods. NMR spectra were acquired at 298 K on a Bruker Avance 400 ( 1 H: 400 MHz, 31 P: 162 MHz, 13 C: 101 MHz, 119 Sn: 149 MHz) or 500 ( 1 H: 500 MHz, 31 P: 202 MHz, 13 C: 126 MHz) or 600 ( 1 H: 600 MHz, 31 P: 243 MHz, 13 C: 151 MHz) NMR spectrometer. The 1 H, 13 C{ 1 H} spectra were referenced to residual internal C 6 H 6 , 31 P spectra was referenced externally to an 85% H 3 PO 4 solution in H 2 O, while 119 Sn spectra was referenced with respect to SnMe 4 . The provided data is presented as follows: chemical shift, multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, sept = septet, m = multiplet and/or multiple resonances), coupling constant in hertz (Hz), integration and attribution). Deuterated solvent, such as C 6 D 6 , THF-d 8 , CDCl 3, were degassed by employing three freeze-pump-thaw cycles and stored over activated molecular sieves in the glove box. High-resolution mass spectrometry (HRMS) was conducted using a Thermo Fisher Scientific Q-Exactive MS System. Infrared spectra were recorded on a FT-IR spectrometer (Bruker ALPHA II) using a DLaTGS detector. UV-Vis absorption spectra were recorded on Lambda 365 spectrophotometer (PerkinElmer) at room temperature. Elemental analyses (C, H, N) were conducted utilizing a Vario Micro Cube analyzer (Elementar, Germany). Crystallographic methods. Crystal data was collected on a Bruker D8 VENTURE Diffractometer equipped with an Excillum METALJET diffractometer utilizing Ga-Kα (λ = 1.34139) radiation by APEX-Ⅲ software suite. 57 SAINT was employed for integrating frames data. And the data was corrected for absorption effects using the empirical multi-scan method (SADABS). 58 The structures were solved using the SHELXT 59 structure solution program through the Intrinsic Phasing solution method and refined through Least Squares minimization method using SHELXL 60 in the graphical user interface Olex2. 61 Anisotropic refinement was applied to all non-hydrogen atoms, while structure factor calculations accounted for hydrogen atoms. The hydrogen atoms were positioned according to idealized geometric positions. Synthesis of 2 . A solution of t BuOK (21.5 mg, 0.19 mmol) in THF (3.0 mL) was gradually added to a THF solution of 1 (100 mg, 0.19 mmol) (3.0 mL) at a temperature of –35℃. The resulting mixture was stirred for 10 minutes at –35℃, followed by warming to room temperature and subsequent stirring for 7 hours. This reaction resulted in the complete consumption of 1 , yielding the formation of 1a ( 31 P NMR (THF): 131 ppm (s)). The solution was then cooled back to –35℃, and a THF (3.0 mL) solution of 2,6-Mes 2 C 6 H 3 SnCl (89.4 mg, 0.19 mmol) was added slowly. After 10 minutes of stirring in the absence of light, all volatile components were removed under vacuum, resulting in the formation of a deep red oil. Pentane was introduced into the mixture, which was then filtered through a Celite pad, yielding a red solution. The remaining volatiles were subsequently removed under vacuum, and the resulting red powder was washed with cold pentane (3.0 mL), resulting in the isolation of 2 as a yellow solid (133 mg, 0.15 mmol) in a yield of 79%. Yellow crystals of 2 suitable for single-crystal X-ray diffraction were obtained by allowing a concentrated pentane solution to undergo slow evaporation at –30℃. 1 H NMR (500 MHz, C 6 D 6 ): δ (ppm) 1.01 (d, 3 J H-H = 6.8 Hz, 6H, two sets of CH(C H 3 ) 2 of Dipp), 1.21 (d, 3 J H-H = 7.1 Hz, 6H, two sets of CH(C H 3 ) 2 of Dipp), 1.30 (d, 3 J H-H = 6.9 Hz, 12H, four sets of CH(C H 3 ) 2 of Dipp), 1.97 (s, 12H, four sets of o -C H 3 of Ter-Mes), 2.21 (s, 6H, two sets of p -C H 3 of Ter-Mes), 3.11 (sept, 3 J H-H = 7.1 Hz, 2H, two sets of C H (CH 3 ) 2 of Dipp), 3.55 – 3.62 (m, 2H, NC H 2 ), 3.94 (sept, 3 J H-H = 6.9 Hz, 2H, two sets of C H (CH 3 ) 2 of Dipp), 3.98 – 4.09 (m, 2H, NC H 2 ), 6.55 (s, 4H, m -Mes), 6.86 (d, 3 J H-H = 7.5 Hz, 2H, m -C 6 H 3 of Ter), 7.08 – 7.16 (m, 4H, Ar- H ), 7.25 (t, 3 J H-H = 7.6 Hz, 3H, Ar- H ). 13 C{ 1 H} NMR (126 MHz, C 6 D 6 ): δ (ppm) 21.3, 21.5 (d, 4 J P-C = 4.0 Hz, C H(CH 3 ) 2 ), 24.0, 24.2, 25.8, 26.1, 27.9, 29.0 (d, 4 J P-C = 9.1 Hz, C H(CH 3 ) 2 ), 55.2 (d, 2 J P-C = 6.7 Hz, N C H 2 ), 124.6, 124.7, 127.5, 128.9, 129.0, 129.5, 136.4, 137.2, 139.4 (d, 2 J P-C = 13.9 Hz, P-N- C Ar ), 146.9, 149.0, 150.1, 174.8 (d, 3 J P-C = 15.0 Hz, Sn- o - C Ar ). (Note: The signal corresponding to the quaternary carbon in close proximity to both Sn and P was not observed in the spectrum.). 31 P NMR (243 MHz, C 6 D 6 ): δ (ppm) 125.3 (s). 119 Sn NMR (149 MHz, C 6 D 6 ): δ (ppm) 92.7 (s). HRMS [M-N 2 +H] + C 51 H 64 N 2 PSn + calc. 855.38236 m/z, found 855.38195 m/z. IR (ATR, neat): v = 2901, 1966 (N=N stretching), 1440, 1103, 961, 519 cm – 1 . Synthesis of 3. A sample of compound 2 (234 mg, 0.265 mmol) was sealed in thick-walled pressure bottle. Subsequently, the solid was exposed to 303 nm light for a duration of 30 minutes at room temperature, resulting in the clean formation of compound 3 . Afterward, the resulting brown powder was washed with 2 mL of cold pentane. This procedure yielded compound 3 as a yellow solid (217 mg, 0.254 mmol, 96% yield). To obtain suitable single-crystal samples for X-ray diffraction analysis, yellow crystals of compound 3 were grown by gradually evaporating a concentrated pentane solution at a temperature of –30 °C over a duration of 48 hours. 1 H NMR (600 MHz, C 6 D 6 ): δ (ppm) 1.20 (d, 3 J H-H = 6.9 Hz, 12H, four sets of CH(C H 3 ) 2 of Dipp), 1.23 (d, 3 J H-H = 6.8 Hz, 12H, four sets of CH(C H 3 ) 2 of Dipp), 2.13 (s,12H, four sets of o -C H 3 of Ter-Mes), 2.26 (s, 6H, two sets of p -C H 3 of Ter-Mes), 3.26 (d, 3 J H-H = 6.2 Hz, 4H, two sets of NC H 2 ), 3.45 (sept, 3 J H-H = 6.9 Hz, 4H, four sets of C H (CH 3 ) 2 of Dipp), 6.56 (s, 4H, m -Mes), 6.98 (d, 3 J H-H = 7.5 Hz, 2H, m -C 6 H 3 of Ter), 7.11 (d, 3 J H-H = 7.5 Hz, 4H, Ar- H ), 7.24 (q, 3 J H-H = 8.0 Hz, 3H, Ar- H ). 13 C { 1 H} NMR (151 MHz, C 6 D 6 ): δ (ppm) 21.5, 21.8, 24.7, 25.0, 29.2, 47.8 (d, 2 J P-C = 8.1 Hz, N C H 2 ), 124.5, 127.5, 127.6, 128.3, 128.5, 128.6, 130.5 (d, 1 J P-C = 50.1 Hz, P C Sn), 134.9 (d, 2 J P-C = 3.8 Hz, P-N- C Ar ), 135.7, 136.6, 138.3, 146.5, 148.6, 179.5 (d, 3 J P-C = 35.4 Hz, Sn- o - C Ar ). 31 P NMR (243 MHz, C 6 D 6 ): δ (ppm) 67.9 (singlet with two satellites, 2 J Sn-P = 168.7 Hz). 119 Sn NMR (149 MHz, C 6 D 6 ): δ 1149.3 (d, 2 J Sn-P = 168.7 Hz). HRMS [M+H] + C 51 H 64 N 2 PSn + calc. 855.38236 m/z, found 855.38196 m/z. IR (ATR, neat): v = 2952, 1364, 1178, 909, 755, 537 cm – 1 . Anal. Calcd for C 51 H 63 N 2 PSn: C, 71.75; H, 7.44; N, 3.28; Found: C, 70.62; H, 7.41; N, 3.35. Synthesis of 4 . A solution of 1-adamantyl isocyanide (AdNC) (6 mg, 0.374 mmol) in tetrahydrofuran (THF) (2.0 mL) was slowly introduced into another THF solution containing 3 (32 mg, 0.374 mmol) (2.0 mL) at room temperature. The resulting mixture was stirred at room temperature for 20 minutes, followed by the removal of volatiles under vacuum. The resulting yellow powder was subsequently washed with 1.0 mL of cold hexane, resulting in the formation of yellow solid 4 (25 mg, 0.0246 mmol) with a yield of 66%. To obtain yellow crystals suitable for single-crystal X-ray diffraction analysis, a concentrated hexane solution of compound 4 was subjected to slow evaporation at –30°C. 1 H NMR (600 MHz, C 6 D 6 ): δ (ppm) 0.98 (d, 3 J H-H = 6.7 Hz, 6H, two sets of CH(C H 3 ) 2 of Dipp), 1.26 (d, 3 J H-H = 6.8 Hz, 6H, two sets of CH(C H 3 ) 2 of Dipp), 1.31 (d, 3 J H-H = 6.9 Hz, 6H, two sets of CH(C H 3 ) 2 of Dipp), 1.35 (d, 3 J H-H = 6.9 Hz, 6H, two sets of CH(C H 3 ) 2 of Dipp), 1.39 – 1.44 (m, 2H, Ad- H ), 1.46 (s, 6H, Ad- H ), 1.48 (s, 1H, Ad- H ), 1.54 – 1.57 (m, 1H, Ad- H ), 1.66 (s, 1H, Ad- H ), 1.87 (s, 4H, Ad- H overlapped with o -C H 3 of Ter-Mes), 1.89 (s, 9 H, three sets of o -C H 3 ), 2.24 (s, 9H, Ad- H overlapped with p -C H 3 of Ter-Mes), 3.14 – 3.23 (m, 2H, NC H 2 ), 3.76 (sept, 3 J H-H = 6.9 Hz, 2H, two sets of C H (CH 3 ) 2 ), 3.86 (sept, 3 J H-H = 6.9 Hz, 2H, two sets of C H (CH 3 ) 2 ), 3.92 – 4.07 (m, 2 H, NC H 2 ), 6.55 (s, 4H, m -Mes), 6.87 (d, 3 J H-H = 7.4 Hz, 2H, m -C 6 H 3 of Ter), 7.14 (s, 1H, Ar- H ), 7.20 – 7.26 (m, 4H, Ar- H ), 7.31 (t, 3 J H-H = 7.6 Hz, 2H, Ar- H ). 13 C { 1 H} NMR (151 MHz, C 6 D 6 ): δ (ppm) 21.3, 21.4, 23.6, 25.1, 26.1, 26.8, 27.7, 28.8 (d, 4 J P-C = 6.5 Hz, C H(CH 3 ) 2 ), 30.1, 36.2, 44.7, 55.3 (d, 2 J P-C = 7.3 Hz, N C H 2 ), 57.5, 102.3 (d, J J P-C = 156.1 Hz, P C Sn), 124.8 (d, 2 J P-C = 59.9 Hz, C C N), 127.1, 128.8, 136.7, 136.9, 141.0 (d, 2 J P-C = 14.2 Hz, P-N- C Ar ), 146.9, 149.4, 150.1, 161.9, 177.0 (Sn- o - C Ar ). 31 P NMR (243 MHz, C 6 D 6 ): δ (ppm) 112.2 (s). 119 Sn NMR (149 MHz, C 6 D 6 ): δ (ppm)1486.8 (s). HRMS [M+H] + C 62 H 79 N 3 PSn + calc. 1016.50281 m/z, found 1016.50629 m/z. IR (ATR, neat): v =2908, 1967 (CCN stretching), 1441, 1056, 804, 766 cm – 1 . Anal. Calcd for C 62 H 78 N 3 PSn: C, 73.37; H, 7.75; N, 4.14; Found: C, 72.97; H, 7.83; N, 4.21. Synthesis of 5 . An excess of 2,3-dimethyl-1,3-butadiene was introduced into a solution of compound 3 (31 mg, 0.0364 mmol) in THF (1.0 mL). The resulting mixture was stirred for 16 hours at room temperature. Subsequently, all volatiles were removed under vacuum, resulting in the formation of a brown oil. The brown oil was dissolved in 0.5 mL of hexane and stored at -35°C in a freezer for a duration of one week, leading to the formation of colorless crystals of product 5 (22 mg, 0.0235 mmol) with a yield of 65%. 1 H NMR (600 MHz, C 6 D 6 ): δ (ppm) 0.34 (d, 2 J H-H = 15.7 Hz, 2H, SnC H 2 ), 0.81 (d, 2 J H-H = 15.5 Hz, 2H, SnC H 2 ), 1.24 (d, 3 J H-H = 5.4 Hz, 12H, four sets of CH(C H 3 ) 2 of Dipp), 1.30 (d, 3 J H-H = 5.4 Hz, 12H, four sets of CH(C H 3 ) 2 of Dipp), 1.62 (s, 6H, two sets of C H 3 of SnCH 2 CCH 3 ), 2.04 (s,12H, four sets of o -C H 3 of Ter-Mes), 2.31 (s, 6H, four sets of p -C H 3 of Ter-Mes), 3.23 (d, 3 J H-H = 5.4 Hz, 4H, four sets of C H (CH 3 ) 2 ), 3.40 – 3.51 (m, 4H, two sets of NC H 2 ), 6.83 (s, 4H, m -Mes), 6.87 (d, 3 J H-H = 7.6 Hz, 2H, m -C 6 H 3 of Ter), 7.08 (d, 3 J H-H = 7.4 Hz, 4H, Ar- H ), 7.16 – 7.20 (m, 3H, Ar- H ). 13 C{ 1 H} NMR (151 MHz, C 6 D 6 ): δ (ppm) 21.4, 21.4, 21.6, 24.7, 25.0, 27.3, 29.3, 47.7 (d, 2 J P-C = 6.1 Hz, N C H 2 ), 124.4, 127.6, 128.4, 128.6, 128.6, 129.1, 130.9, 130.9 (d, 1 J P-C = 34.0 Hz, P C Sn), 135.5, 135.6, 136.7, 142.0, 148.7, 150.0. 31 P NMR (243 MHz, C 6 D 6 ): δ (ppm) 3.7 (singlet with two satellites, 2 J Sn-P =181.4 Hz). 119 Sn NMR (149 MHz, C 6 D 6 ): δ (ppm) –43.6 (d, 2 J Sn-P =181.4 Hz). HRMS [M+H] + C 57 H 74 N 2 PSn + calc. 937.46061 m/z, found 937.46191 m/z. IR (ATR, neat): v = 2960, 1442, 1256, 1074, 847, 802 cm – 1 . Anal. Calcd for C 57 H 73 N 2 PSn: C, 73.15; H, 7.86; N, 2.99; Found: C, 71.29; H, 7.86; N, 3.09. Synthesis of 6 . Inside the glovebox, a pre-cooled solution of THF (3 mL) was added dropwise to a mixture comprising compound 3 (38.6 mg, 0.0452 mmol) and Et 3 N·HCl (12.4 mg, 0.0904 mmol). Following stirring at –35°C for 15 minutes, the resulting mixture was filtered through a Celite pad, resulting in the formation of a white solution. Subsequently, all volatiles were removed under vacuum. The resulting white powder was then washed with 3.0 mL of cold hexane, affording white solid 6 (28.5 mg, 0.307 mmol) with a yield of 68%. To obtain colorless crystals suitable for single-crystal X-ray diffraction analysis, a concentrated hexane solution of compound 6 was subjected to slow evaporation at –30°C. 1 H NMR (600 MHz, C 6 D 6 ): δ (ppm) 1.21 (d, 3 J H-H = 6.6 Hz, 6H, two sets of CH(C H 3 ) 2 of Dipp), 1.28 (m, 12H, four sets of CH(C H 3 ) 2 of Dipp), 1.41 (d, 3 J H-H = 6.6 Hz, 6H, two sets of CH(C H 3 ) 2 of Dipp), 1.64 (d, 2 J H-H = 5.0 Hz, 2H, PC H 2 ), 2.00 (s, 12H, four sets of o -C H 3 of Ter-Mes), 2.18 (s, 6H, two sets of p -C H 3 of Ter-Mes), 3.08 – 3.20 (m, 2H, NC H 2 ), 3.26 – 3.38 (m, 2H, two sets of C H (CH 3 ) 2 of Dipp), 3.61 (sept, 3 J H-H = 6.6 Hz, 2H, two sets of C H (CH 3 ) 2 of Dipp), 3.72 (m, 2H, NC H 2 ), 6.66 (s, 4H, m -Mes), 6.78 (d, 3 J H-H = 7.5 Hz, 2H, m -C 6 H 3 of Ter), 7.08 (t, 3 J H-H = 7.5 Hz, 1H, p -C 6 H 3 of Ter), 7.15 (s, 2H, Ar- H ), 7.17 (s, 2H, Ar- H ), 7.19 – 7.23 (m, 2H, Ar- H ). 13 C{ 1 H} NMR (151 MHz, C 6 D 6 ): δ (ppm) 21.3, 21.6 (d, 4 J P-C = 3.0 Hz, C H(CH 3 ) 2 ), 24.0, 24.8, 26.5, 29.0, 29.2 (d, 4 J P-C = 11.9 Hz, C H(CH 3 ) 2 ), 36.2 (d, 1 J P-C = 89.2 Hz, P C H 2 ), 55.1 (d, 2 J P-C = 6.1 Hz, N C H 2 ), 124.5, 124.8, 127.0, 128.3, 129.1, 129.6, 131.9, 136.8, 138.0, 138.2, 140.2 (d, 2 J P-C = 12.5 Hz, P-N- C Ar ), 141.6, 148.0, 149.0, 149.4. 31 P NMR (243 MHz, C 6 D 6 ): δ (ppm) 111.3 (singlet with two satellites, 2 J Sn-P = 263.1 Hz). 119 Sn NMR (149 MHz, C 6 D 6 ): δ (ppm) –13.2 (d, 2 J Sn-P = 263.1 Hz). HRMS [M] + C 51 H 65 N 2 Cl 2 PSn + calc. 926.32789 m/z, found 926.32904 m/z. HRMS [M] + C 51 H 65 N 2 Cl 37 ClPSn + calc. 928.32494 m/z, found 928.33063 m/z. IR (ATR, neat): v = 2963, 1443, 1070, 850, 804, 757 cm – 1 . Anal. Calcd for C 51 H 65 Cl 2 N 2 PSn: C, 66.10; H, 7.07; N, 3.02; Found: C, 63.11; H, 7.00; N, 2.93. Synthesis of 7. A solution of isopropyl isocyanate ( i PrNCO) (10 mg, 0.12 mmol) in THF (2.0 mL) was slowly introduced into another THF solution containing 3 (50 mg, 0.059 mmol) (2.0 mL) at –35°C. The resulting mixture was stirred at room temperature for 10 minutes, followed by the removal of volatiles under vacuum. The resulting white powder was subsequently washed with 1.0 mL of cold pentane, resulting in the formation of white solid 7 (32 mg, 0.031 mmol) with a yield of 54%. To obtain colorless crystals suitable for single-crystal X-ray diffraction analysis, a concentrated pentane and toluene solution of compound 7 was subjected to slow evaporation at –30°C. 1 H NMR (500 MHz, C 6 D 6 ): δ (ppm) 0.16 (t, 3 J H-H = 7.5 Hz, 6H, two sets of NCH(C H 3 ) 2 ), 0.54 (s, 3H, NC(C H 3 ) 2 N), 0.70 (s, 3H, NC(C H 3 ) 2 N), 1.04 (d, 3 J H-H = 6.7 Hz, 3H, CH(C H 3 ) 2 of Dipp), 1.16 (d, 3 J H-H = 6.7 Hz, 3H, CH(C H 3 ) 2 of Dipp), 1.26 (d, 3 J H-H = 6.9 Hz, 3H, CH(C H 3 ) 2 of Dipp), 1.40 (d, 3 J H-H = 6.6 Hz, 6H, two sets of CH(C H 3 ) 2 of Dipp), 1.45 (d, 3 J H-H = 6.9 Hz, 3H, CH(C H 3 ) 2 of Dipp), 1.68 (d, J = 6.7 Hz, 3H, CH(C H 3 ) 2 of Dipp), 1.72 (d, 3 J H-H = 6.6 Hz, 3H, CH(C H 3 ) 2 of Dipp), 2.06 (s, 3H, C H 3 of Ter-Mes), 2.20 (s, 3H, C H 3 of Ter-Mes), 2.30 (s, 3H, C H 3 of Ter-Mes), 2.34 (s, 3H, C H 3 of Ter-Mes), 2.40 (t, 3 J H-H = 7.5 Hz, 1H, NC H Me 2 ), 2.49 (s, 3H, C H 3 of Ter-Mes), 2.55 (s, 3H, C H 3 of Ter-Mes), 3.25 – 3.39 (m, 1H, NC H 2 ), 3.64 (sept, 3 J H-H = 6.7 Hz, 1H, C H (CH 3 ) 2 of Dipp), 3.68 – 3.75 (m, 1H, NC H 2 ), 3.77 – 3.86 (m, 1H, NC H 2 ), 4.01 (sept, 3 J H-H = 6.9 Hz, 1H, C H (CH 3 ) 2 of Dipp), 4.22 – 4.31 (m, 1H, NC H 2 ), 4.35 (sept, 3 J H-H = 6.7 Hz, 1H, C H (CH 3 ) 2 of Dipp), 4.43 (sept, 3 J H-H = 6.6 Hz, 1H, C H (CH 3 ) 2 of Dipp), 6.77 – 6.90 (m, 4H, Ar- H ), 6.94 – 7.03 (m, 1H, Ar- H ), 7.16 – 7.21 (m, 3H, Ar- H ), 7.20 – 7.26 (m, 4H, Ar- H ), 7.30 (t, 3 J H-H = 7.7 Hz, 1H, p -C 6 H 3 of Ter), 7.41 (d, 3 J P-H = 12.0 Hz, 1H, PCC H ). 13 C{ 1 H} NMR (126 MHz, C 6 D 6 ): δ (ppm) 21.0, 21.4, 21.8, 21.9, 22.5, 22.6, 22.9, 23.1, 25.0, 25.3, 25.5, 25.9, 26.0, 26.2, 26.6, 27.1, 27.4, 27.6, 28.8, 29.2, 29.4, 47.7 (N C H), 48.8 (d, 2 J P-C = 13.6 Hz, N C H 2 ), 50.5 (d, 2 J P-C = 13.4 Hz, N C H 2 ), 75.8 (N C N), 90.3 (d, 1 J P-C = 192.1 Hz, P- C ), 124.2, 125.2, 125.4, 128.8 (d, 2 J P-C = 12.0 Hz, P-N- C , Ar- C ), 129.2, 129.9, 135.4, 135.5, 136.1, 136.8, 137.0, 138.0, 139.6, 142.7, 146.2, 148.2, 150.7, 150.9 (d, 3 J P-C = 3.3 Hz, P-N-C- C , Ar- C ), 151.0, 151.2, 154.7 (d, 2 J P-C = 16.2 Hz, PC C H), 169.0 (d, 2 J P-C = 6.1 Hz, O- C -N), 174.3 (Sn- o - C Ar ). 31 P NMR (243 MHz, C 6 D 6 ): δ (ppm) 15.7. 119 Sn NMR (149 MHz, C 6 D 6 ): δ (ppm) 342.9. HRMS [M+H] + C 59 H 78 N 4 O 2 PSn + calc. 1025.48789 m/z, found 1025.49072 m/z. IR (ATR, neat): v = 2946, 1587, 1442, 1292, 1094, 805 cm – 1 . Anal. Calcd for C 59 H 77 N 4 O 2 PSn: C, 69.21; H, 7.58; N, 5.47; Found: C, 66.72; H, 7.64; N, 5.77. Computational details Geometry optimizations were carried out using the Gaussian 16 package 62 with the BP86 functional 63,64 augmented with the D3BJ version of Grimme’s empirical dispersion correction. 65,66,67 The def2-TZVPP basis set was used for all the atoms. Frequency calculations at the same level of theory were performed to identify the number of imaginary frequencies (zero for local minimum). Natural bond orbital (NBO) calculations and natural resonance theory (NRT) calculations were carried out using NBO 7.0 program 68 at the BP86-D3(BJ)/def2-TZVPP level of theory, intrinsic bond orbitals (IBOs) were carried out using ORCA program 69 at the same level. Optimized structures were visualized by the Chemcraft 70 or IBOview program. 46 The electron localization function (ELF) analysis 47 were carried out using Amsterdam Modeling Suite 71 at the BP86-D3(BJ)/TZP level of theory using the BP86-D3(BJ)/def2-TZVPP optimized geometries, the relativistic scalar effect was included by using the zeroth-order regular approximation (ZORA). 72,73 TD-DFT calculations were carried out at the M062X/def2-TZVP level of theory. Isotropic shifts for Int2A were computed at the GIAO-B97-2 74 /Def2-TZVP 75,76 //BP86-D3(BJ)/def2-SVP level of theory. Data availability Crystallographic data for the structures reported in this Article have been deposited at the Cambridge Crystallographic Data Centre, under deposition numbers 2261177 ( 2 ), 2261179 ( 3 ), 2261180 ( 4 ), 2261178 ( 5 ), 2261181 ( 6 ) and 2261213 ( 7 ). Copies of the data can be obtained free of charge via https://www.ccdc.cam.ac.uk/structures/. All other data are presented in the main text and the Supplementary Information, and are also available from the corresponding authors on reasonable request. Methods-only references APEX suite of crystallographic software (APEX 3 version 2015.5-2 & Bruker AXS Inc.: Madison, Wisconsin, USA. 2015). Bruker AXS Inc., in Bruker Apex CCD, SAINT v8.40B, WI, USA, Madison, 2019. Sheldrick, G. M. SHELXT-Integrated space-group and crystal-structure determination. Acta Cryst. A , A71 , 3-8 (2015). Sheldrick, G. M. Crystal structure refinement with SHELXL. Acta Cryst. C71 , 3–8 (2015). Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K., Puschmann, H. OLEX2: a complete structure solution, refinement and analysis program. J. Appl. Cryst. 42 , 339- 341 (2009). Frisch, M. J. et al. Gaussin 16 rev. B.01 (Gaussian, Inc., Wallingford CT, 2016). Lee, C., Yang, W. & Parr, R. G. Development of the colle-salvetti correlation-energy formula into a functional of the electron density. Phys. Rev. B 37 , 785-789 (1988). Stephens, P. J., Devlin, F. J., Chabalowski, C. F. & Frisch, M. J. Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields. J. Phys. Chem. 98 , 11623-11627 (1994). Grimme, S., Antony, J., Ehrlich, S. & Krieg, H. A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu. J. Chem. Phys . 132 , 154104-154133 (2010). Grimme, S. Semiempirical GGA-type density functional constructed with a long-range dispersion correction, J. Comput. Chem. 27 , 1787-1799 (2006). Grimme, S. Accurate description of van der waals complexes by density functional theory including empirical corrections. J. Comput. Chem . 25 , 1463-1473 (2004). Glendening, E. D., Badenhoop, J. K., Reed, A. E., Carpenter, J. E., Bohmann, J. A., Morales, C. M., Karafiloglou P., Landis C. R. & Weinhold, F., NBO 7.0, University of Wisconsin: Madison, WI, 2018. Neese, F. The ORCA program system. WIREs Comput. Mol. Sci. 2 , 73-78 (2012). Andrienko, G. A. ChemCraft, http://www.chemcraftprog.com. Van Gisbergen, S., Snijders, J. & Ziegler, T. Chemistry with ADF. J. Comput. Chem 22 , 931-967 (2001). Chang, C., Pelissier, M. & Durand, P. Regular two-component pauli-like effective hamiltonians in dirac theory. Phys. Scr . 34 , 394-404 (1986). Heully, J. L., Lindgren, I., Lindroth, E., Lundqvist, S. & Martensson-Pendrill, A. M. Diagonalisation of the dirac hamiltonian as a basis for a relativistic many-body procedure. J. Phys. B 19 , 2799-2815 (1986). Wilson, P. J., Bradley, T. J. & Tozer, D. J. Hybrid exchange-correlation functional determined from thermochemical data and ab initio potentials, J. Chem. Phys. 115 , 9233-9242 (2001). Weigend, F., Ahlrichs, R. Balanced basis sets of split valence, triple zeta vlence and quadruple zeta valence quality for H to Rn: design and assessment of accuracy, Phys. Chem. Chem. Phys. 7 , 3297-3305 (2005). Weigend, F. Accurate coulomb-fitting basis sets for H to Rn, Phys. Chem. Chem. Phys. 8 , 1057-1065 (2006). Additional Declarations There is NO Competing Interest. Supplementary Files figure5.cdx Compound2.cif Supplementary Data Set 1 Compound3.cif Supplementary Data Set 2 Compound4.cif Supplementary Data Set 3 Compound5.cif Supplementary Data Set 4 Compound6.cif Supplementary Data Set 5 Compound7.cif Supplementary Data Set 6 CartesianCooradinates.xlsx Supplementary Data Set 7 SupportingInformation.pdf Cite Share Download PDF Status: Published Journal Publication published 17 Jun, 2024 Read the published version in Nature Chemistry → Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-3050761","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":283728239,"identity":"1af1a5af-6b2e-4790-aa06-616db10000cc","order_by":0,"name":"Liu Leo Liu","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA9UlEQVRIiWNgGAWjYBACPmYGxgMMDBY8DOwNEBEDIJbAp4WNmYEBqEWCh4EHSDEkEKOFAaIFiBKI1cLOY3DgQ4WEjMHN588kf/6wkTdnYD54m4fBLg+3w3gMDs44I8FjcDvHTJonIc1wZwNbsjUPQ3IxPi2HedvAWtikGRIOJxgc4AHqZTiQ2IBPy1+QlpvHn0n+SPgP1ML/jbAWRpCWGwxmEjwJB0C2sBHQwlZwsAfoF8kzOcbWPGnJhhsOsxlbzjFIxqmFn//wxgc/Kmzs+Y4ff3jzh42dvMHx5oc33lTY4dSCBTCDCAPi1Y+CUTAKRsEowAQAO3pMk/Hi5vsAAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0003-4934-0367","institution":"Southern University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"Liu","middleName":"Leo","lastName":"Liu","suffix":""},{"id":283728240,"identity":"08c9f25f-94b2-4a1c-8300-bb1ef5115df9","order_by":1,"name":"Xin-Feng Wang","email":"","orcid":"https://orcid.org/0009-0003-5834-4009","institution":"Southern University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Xin-Feng","middleName":"","lastName":"Wang","suffix":""},{"id":283728241,"identity":"fd03815c-3625-44be-bcf0-f780f7155378","order_by":2,"name":"Chaopeng Hu","email":"","orcid":"https://orcid.org/0000-0002-5746-3650","institution":"Southern University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Chaopeng","middleName":"","lastName":"Hu","suffix":""},{"id":283728242,"identity":"94108495-d00b-49c6-9619-286ffa164781","order_by":3,"name":"Jiancheng Li","email":"","orcid":"https://orcid.org/0000-0002-5873-730X","institution":"Southern University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Jiancheng","middleName":"","lastName":"Li","suffix":""},{"id":283728243,"identity":"51cc0b8e-f160-4822-8fcc-038700a1452e","order_by":4,"name":"Rui Wei","email":"","orcid":"","institution":"Southern University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Rui","middleName":"","lastName":"Wei","suffix":""},{"id":283728244,"identity":"e3a059fc-1e73-4004-8aaa-7a5e7e4653ec","order_by":5,"name":"Xin Zhang","email":"","orcid":"","institution":"Southern University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Xin","middleName":"","lastName":"Zhang","suffix":""}],"badges":[],"createdAt":"2023-06-12 02:56:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-3050761/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-3050761/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41557-024-01555-4","type":"published","date":"2024-06-17T04:00:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":54033619,"identity":"6f855520-c911-44e9-9bf3-758c64014003","added_by":"auto","created_at":"2024-04-03 16:36:06","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":23949,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eConceptual overview and notable examples.\u003c/strong\u003e \u003cstrong\u003ea\u003c/strong\u003e, Comparative illustration of alkynes alongside their heavier group 14 analogs. \u003cstrong\u003eb\u003c/strong\u003e, A selection of known compounds: singlet carbene \u003cstrong\u003eA\u003c/strong\u003e, base-stabilized silynes \u003cstrong\u003eB\u003c/strong\u003e and \u003cstrong\u003eD\u003c/strong\u003e, base-stabilized germynes \u003cstrong\u003eC\u003c/strong\u003e, copper carbyne anion complex \u003cstrong\u003eE\u003c/strong\u003e, and transient stannyne \u003cstrong\u003eF\u003c/strong\u003e. PR\u003csub\u003e2\u003c/sub\u003e = P(N\u003csup\u003e\u003cem\u003et\u003c/em\u003e\u003c/sup\u003eBu)\u003csub\u003e2\u003c/sub\u003eSiMe\u003csub\u003e2\u003c/sub\u003e or P(N\u003csup\u003e\u003cem\u003ei\u003c/em\u003e\u003c/sup\u003ePrCH\u003csub\u003e2\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e; \u003csup\u003eTip\u003c/sup\u003eTer = 2,6-Tip\u003csub\u003e2\u003c/sub\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e (Tip = 2,4,6-\u003csup\u003e\u003cem\u003ei\u003c/em\u003e\u003c/sup\u003ePr\u003csub\u003e3\u003c/sub\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e2\u003c/sub\u003e); Dipp = 2,6-diisopropylphenyl. Dipentp = 2,6-di-(3-pentyl)phenyl.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/6600edd4b0ef9aa3ff04c01a.png"},{"id":54033624,"identity":"ac1fadb3-e128-4074-bf41-91014e227f7c","added_by":"auto","created_at":"2024-04-03 16:36:07","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":23949,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSynthesis of stannylenyl diazomethane 2 and stannyne 3 along with its resonance forms. \u003c/strong\u003eCondition ⅰ) reagent: 1.0 equiv. of potassium\u003cem\u003e tert\u003c/em\u003e-butoxide (\u003csup\u003e\u003cem\u003et\u003c/em\u003e\u003c/sup\u003eBuOK); solvent: tetrahydrofuran (THF); reaction temperature (time): –35 °C (10 minutes) to room temperature (7 hours). Condition ⅱ) reagent: 1.0 equiv. of TerSnCl (Ter = 2,6-Mes\u003csub\u003e2\u003c/sub\u003eC\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e, Mes = mesityl); solvent: THF; reaction temperature (time): –35 °C (10 minutes) in the absence of light. Condition ⅲ) reagent: neat \u003cstrong\u003e2\u003c/strong\u003e under irradiation of 303 nm light; reaction temperature (time): room temperature (10 minutes).\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/eea0cfdf2a83228d81caca09.png"},{"id":54033613,"identity":"b26e8470-6ce5-4b7d-a135-01b52e992d3c","added_by":"auto","created_at":"2024-04-03 16:36:06","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":184255,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSingle-crystal X-ray diffraction solid-state structures of stannylenyl diazomethane 2 and stannyne 3 at 100 K with thermal ellipsoids at the 30% probability level and selective labelling. a\u003c/strong\u003e, Solid-state structures of \u003cstrong\u003e2\u003c/strong\u003e. Selected experimental bond length (Å) and angles (deg): P(1)–C(1) 1.879(8); C(1)–N(1) 1.331(10); N(1)–N(2) 1.145(10); C(1)–Sn(1) 2.134(8); Sn(1)–C(2) 2.168(8); P(1)–C(1)–Sn(1) [138.0(5)]; C(1)–Sn(1)–C(2) [105.6(5)]. \u003cstrong\u003eb\u003c/strong\u003e, Solid-state structures of \u003cstrong\u003e3\u003c/strong\u003e. Selected experimental bond length (Å) and angles (deg): P(1)–C(1) 1.561(6); C(1)–Sn(1) 2.082(6); Sn(1)–C(2) 2.217(5); P(1)–C(1)–Sn(1) [136.7(3)]; C(1)–Sn(1)–C(2) [98.0(2)]. Hydrogen atoms are omitted for clarity.\u003c/p\u003e","description":"","filename":"figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/f92c4887adebf87652253d50.png"},{"id":54034234,"identity":"7b577b2f-0a2f-46c4-968d-e02e308dd48d","added_by":"auto","created_at":"2024-04-03 16:44:06","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1532957,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDepiction of selected frontier molecular orbitals (FMOs) (isovalue = 0.035) and electron localization function (ELF) plot of stannyne 3.\u003c/strong\u003eFMO analysis reveals the multiple bond character of the P(1)−C(1)−Sn(1) chain in \u003cstrong\u003e3 \u003c/strong\u003eand suggests that both C(1) and Sn(1) exhibit ambiphilicity. \u003cstrong\u003ea\u003c/strong\u003e, HOMO: the P(1)−C(1) π-bonding orbital and the lone pair orbital at Sn(1). \u003cstrong\u003eb\u003c/strong\u003e, HOMO–1: P(1)−C(1)−Sn(1) out-of-plane 3-center-2-electron (3c2e) π-bonding orbital. \u003cstrong\u003ec\u003c/strong\u003e, HOMO–2: a slipped C(1)−Sn(1) π bond, exhibiting lone pair characteristics at both C(1) and Sn(1). \u003cstrong\u003ed\u003c/strong\u003e, LUMO: the C(1)−Sn(1) π*-antibonding orbital with the significant vacant 5p orbital character at Sn(1). \u003cstrong\u003ee\u003c/strong\u003e, LUMO+2: the P(1)−C(1) π*-antibonding orbital. \u003cstrong\u003ef\u003c/strong\u003e, The ELF plot of \u003cstrong\u003e3\u003c/strong\u003e shows the ionic interaction between the C and Sn atoms in the P(1)−C(1)−Sn(1) plane, with limited electron density localized at the C(1)−Sn(1) and Sn(1)−C(2) bonds, whereas the P(1)−C(1) bond exhibits a strong covalent character.\u003c/p\u003e","description":"","filename":"figure4.png","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/febca7132b28d87533b27ae9.png"},{"id":54033622,"identity":"45e740fd-2805-4387-9f1f-30c714825da2","added_by":"auto","created_at":"2024-04-03 16:36:07","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":23949,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eThe reactivity of stannyne 3 towards 1-adamantyl isocyanide, 2,3-dimethyl-1,3-butadiene, triethylammonium chloride and isopropyl isocyanate. \u003c/strong\u003eCondition ⅰ) reagent: 1.0 equiv. of 1-adamantyl isocyanide (AdNC); solvent: tetrahydrofuran (THF); reaction temperature (time): room temperature (20 minutes). Condition ⅱ) reagent: excess of 2,3-dimethyl-1,3-butadiene; solvent: THF; reaction temperature (time): room temperature (16 hours). Condition ⅲ) 2.0 equiv. of triethylammonium chloride (Et\u003csub\u003e3\u003c/sub\u003eN·HCl), solvent: THF; reaction temperature (time): –35 °C (15 minutes). Condition ⅳ) 2.0 equiv. of isopropyl isocyanate (\u003csup\u003e\u003cem\u003ei\u003c/em\u003e\u003c/sup\u003ePrNCO), solvent: THF; reaction temperature (time): –35 °C (5 minutes) to room temperature (10 min).\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/b62a8ec7d3d70f5f5c90a272.png"},{"id":54034235,"identity":"8e124881-bfb0-447a-9fd8-520ad035a597","added_by":"auto","created_at":"2024-04-03 16:44:06","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":271925,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSingle-crystal X-ray diffraction solid-state structures of compounds 4, 5, 6 and 7 at 100 K with thermal ellipsoids at the 30% probability level and selective labelling.\u003c/strong\u003e \u003cstrong\u003ea\u003c/strong\u003e, Solid-state structures of \u003cstrong\u003e4\u003c/strong\u003e. Selected experimental bond length (Å) and angles (deg): P(1)–C(1) 1.834(3); C(1)–Sn(1) 2.191(2); Sn(1)–C(2) 2.216(3); P(1)–C(1)–Sn(1) [129.26(13)]; C(1)–Sn(1)–C(2) [104.62(9)]; \u003cstrong\u003eb\u003c/strong\u003e, Solid-state structures of \u003cstrong\u003e5\u003c/strong\u003e. Selected experimental bond length (Å) and angles (deg): P(1)–C(1) 1.568(2); C(1)–Sn(1) 2.080(2); Sn(1)–C(2) 2.1691(18); P(1)–C(1)–Sn(1) [134.47(12)]; C(1)–Sn(1)–C(2) [105.23(7)]; \u003cstrong\u003ec\u003c/strong\u003e, Solid-state structures of \u003cstrong\u003e6\u003c/strong\u003e. Selected experimental bond length (Å) and angles (deg): P(1)–C(1) 1.859(4); C(1)–Sn(1) 2.126(4); Sn(1)–C(2) 2.153(4); P(1)–C(1)–Sn(1) [122.9(2)]; C(1)–Sn(1)–C(2) [125.58(16)]. \u003cstrong\u003ed\u003c/strong\u003e, Solid-state structures of \u003cstrong\u003e7\u003c/strong\u003e. Selected experimental bond length (Å) and angles (deg): P(1)–C(1) 1.784(2); P(1)–O(1) 1.4811(18); C(1)–C(3) 1.376(3); Sn(1)–C(2) 2.233(2); Sn(1)–N(2) 2.257(2); Sn(1)–O(2) 2.2269(16); O(1)–P(1)–C(1) [107.19(10)]; P(1)–C(1)–C(3) [116.57(17)]. Hydrogen atoms except C(1)\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e of \u003cstrong\u003e6\u003c/strong\u003e are omitted for clarity.\u003c/p\u003e","description":"","filename":"figure6.png","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/0230276fdde34bb7812cf130.png"},{"id":58552182,"identity":"ddc55949-55e4-497a-ad87-0f0ffede50a7","added_by":"auto","created_at":"2024-06-18 07:06:23","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3368253,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/f9c3709c-64f4-4b28-8ad5-20bc5520cb4d.pdf"},{"id":54033625,"identity":"ddaed90a-e5c9-4ff9-8999-b01a2e52a92a","added_by":"auto","created_at":"2024-04-03 16:36:07","extension":"cdx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":23380,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"figure5.cdx","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/293e5531fb0c613a01ea6ae5.cdx"},{"id":54033621,"identity":"b68f23e1-6350-4edb-9f39-89edbeb89155","added_by":"auto","created_at":"2024-04-03 16:36:07","extension":"cif","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":1485365,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Data Set 1\u003c/p\u003e","description":"","filename":"Compound2.cif","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/e319b7950a3a61dd7e13d21a.cif"},{"id":54033623,"identity":"f2cdfc1e-773e-4c2d-9475-f170e15549a3","added_by":"auto","created_at":"2024-04-03 16:36:07","extension":"cif","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":1526861,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Data Set 2\u003c/p\u003e","description":"","filename":"Compound3.cif","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/4e548e909844a298f94386c6.cif"},{"id":54033611,"identity":"2ac2c86f-b131-4c1a-86df-deaeb74e0c0b","added_by":"auto","created_at":"2024-04-03 16:36:06","extension":"cif","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":2155114,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Data Set 3\u003c/p\u003e","description":"","filename":"Compound4.cif","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/38fce66981c30a4b88de2b8e.cif"},{"id":54033615,"identity":"270e22a3-0b6a-45b9-aea4-9cf5af867ce4","added_by":"auto","created_at":"2024-04-03 16:36:06","extension":"cif","order_by":7,"title":"","display":"","copyAsset":false,"role":"supplement","size":1953312,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Data Set 4\u003c/p\u003e","description":"","filename":"Compound5.cif","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/8e326c428312a6c74f5b7915.cif"},{"id":54033610,"identity":"2a8ea229-439a-4f11-9a4e-8c20590cdbe5","added_by":"auto","created_at":"2024-04-03 16:36:05","extension":"cif","order_by":8,"title":"","display":"","copyAsset":false,"role":"supplement","size":3987612,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Data Set 5\u003c/p\u003e","description":"","filename":"Compound6.cif","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/c31c697d9b5ec61dd13d065a.cif"},{"id":54033612,"identity":"8e697231-b552-4e4d-bb65-b7cdb5777407","added_by":"auto","created_at":"2024-04-03 16:36:06","extension":"cif","order_by":9,"title":"","display":"","copyAsset":false,"role":"supplement","size":997993,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Data Set 6\u003c/p\u003e","description":"","filename":"Compound7.cif","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/dc752ec78841b9965ea882de.cif"},{"id":54033617,"identity":"05f2f669-0ecb-4b70-b4d9-e03aaaacf899","added_by":"auto","created_at":"2024-04-03 16:36:06","extension":"xlsx","order_by":10,"title":"","display":"","copyAsset":false,"role":"supplement","size":34608,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Data Set 7\u003c/p\u003e","description":"","filename":"CartesianCooradinates.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/58659d45cf2cf062bd100d0c.xlsx"},{"id":54033618,"identity":"0cc31426-8399-4282-9d0c-757d3a34ebc9","added_by":"auto","created_at":"2024-04-03 16:36:06","extension":"pdf","order_by":11,"title":"","display":"","copyAsset":false,"role":"supplement","size":5253068,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"SupportingInformation.pdf","url":"https://assets-eu.researchsquare.com/files/rs-3050761/v1/705f4906fbbbf45954914e47.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"A crystalline stannyne","fulltext":[{"header":"Main Text","content":"\u003cp\u003eAlkynes are ubiquitous organic compounds containing a carbon-carbon triple bond (Fig. 1a). They possess valuable versatility, participating in various reactions that lead to the formation of diverse functional groups and structures.\u003csup\u003e1\u003c/sup\u003e Consequently, alkynes play significant roles in both chemistry and biology. Substituting the carbon atoms involved in the triple bond of alkynes with heavier group 14 elements such as silicon, germanium, tin, and lead provides access to unique compounds known as heavier homonuclear alkyne analogs, namely disilyne,\u003csup\u003e2,3\u003c/sup\u003e digermyne,\u003csup\u003e4\u003c/sup\u003e distannyne,\u003csup\u003e5\u003c/sup\u003e and diplumyne\u003csup\u003e6\u003c/sup\u003e (R\u003csup\u003e1\u003c/sup\u003e\u0026minus;E\u0026equiv;E\u0026minus;R\u003csup\u003e2\u003c/sup\u003e, E = Si, Ge, Sn, Pb) (Fig. 1a). The groups led by Power,\u003csup\u003e4-6\u003c/sup\u003e Sekiguchi\u003csup\u003e2\u003c/sup\u003e and Wiberg\u003csup\u003e3\u003c/sup\u003e made significant contributions by isolating these compounds, opening up avenues for further exploration.\u003csup\u003e7-15\u003c/sup\u003e These compounds possess distinct characteristics compared to linear alkynes due to the second-order Jahn-Teller effect\u003csup\u003e16-19\u003c/sup\u003e observed in the heavier main group analogs. This effect leads to a slipped \u0026pi;-bond and substantial geometric distortion, providing a \u003cem\u003etrans\u003c/em\u003e-bent molecular geometry. These unique electronic features render the heavier element centers ambiphilic, enabling them to display reactivity towards small molecules with strong enthalpic bonds.\u003csup\u003e7-11,20-23\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eBy replacing one carbon atom in alkynes with a heavier group 14 element, their heteronuclear analogs are obtained: silyne, germyne, stannyne, and plumyne (R\u003csup\u003e1\u003c/sup\u003e\u0026minus;C\u0026equiv;E\u0026minus;R\u003csup\u003e2\u003c/sup\u003e, E = Si, Ge, Sn, Pb) (Fig. 1a). Theoretical predictions suggest that similar to R\u003csup\u003e1\u003c/sup\u003e\u0026minus;E\u0026equiv;E\u0026minus;R\u003csup\u003e2\u003c/sup\u003e, the R\u003csup\u003e1\u003c/sup\u003e\u0026minus;C\u0026equiv;E\u0026minus;R\u003csup\u003e2\u003c/sup\u003e compounds adopt a \u003cem\u003etrans\u003c/em\u003e-bent molecular geometry.\u003csup\u003e24-30\u003c/sup\u003e However, without Lewis base stabilization, these compounds are completely unknown as isolable species. A major challenge in synthesizing R\u003csup\u003e1\u003c/sup\u003e\u0026minus;C\u0026equiv;E\u0026minus;R\u003csup\u003e2\u003c/sup\u003e is the energetically favored isomerization of R\u003csup\u003e1\u003c/sup\u003e\u0026minus;C\u0026equiv;E\u0026minus;R\u003csup\u003e2\u003c/sup\u003e into R\u003csup\u003e1\u003c/sup\u003eR\u003csup\u003e2\u003c/sup\u003eC=E, especially when R\u003csup\u003e1\u003c/sup\u003e and R\u003csup\u003e2\u003c/sup\u003e are small substituents.\u003csup\u003e24-30\u003c/sup\u003e Indeed, the isolation of these compounds as stable, isolable species has been a long-standing objective. As of now, the only neutral species proven to be sufficiently stable for structural characterization below \u0026ndash;30 \u0026deg;C are silyne \u003cstrong\u003eB\u003c/strong\u003e\u003csup\u003e31\u003c/sup\u003e and two germynes \u003cstrong\u003eC\u003c/strong\u003e,\u003csup\u003e32\u003c/sup\u003e which were stabilized by a Lewis base,\u0026nbsp;as reported by Kato and Baceiredo over a decade ago (Fig. 1b). It has been observed that they undergo intramolecular rearrangement reactions above this temperature threshold.\u003csup\u003e31,32\u003c/sup\u003e More recently, Kato isolated a base-stabilized cationic silyne \u003cstrong\u003eD\u003c/strong\u003e with moderate stability at room temperature (t\u003csub\u003e1/2\u003c/sub\u003e = 7 days in THF).\u003csup\u003e33\u003c/sup\u003e By contrast, stannyne and plumyne have not yet been identified as isolable species, even in the presence of a Lewis base for stabilization. Based on UV-vis spectroscopic observations, Kira and Sakamoto demonstrated the transient existence of stannyne \u003cstrong\u003eF\u003c/strong\u003e\u003csup\u003e34\u003c/sup\u003e during low-temperature photolysis of the corresponding diazo precursor (\u0026ndash;196 \u0026deg;C). However, \u003cstrong\u003eF\u003c/strong\u003e is considered a highly transient species at room temperature, defying direct observation.\u003csup\u003e34,35\u003c/sup\u003e These findings underscore the inherent difficulty of isolating these highly reactive compounds under typical laboratory conditions.\u003c/p\u003e\n\u003cp\u003eLandmark studies by Bertrand,\u003csup\u003e36\u003c/sup\u003e as well as more recent work by Kato,\u003csup\u003e31,32\u003c/sup\u003e Baceiredo,\u003csup\u003e31,32\u003c/sup\u003e and our group,\u003csup\u003e37,38\u003c/sup\u003e have showcased the remarkable potential of phosphinodiazomethyl anion salt as a versatile synthon for introducing a singlet carbyne anion (R\u0026minus;C\u003csup\u003e\u0026ndash;\u003c/sup\u003e) fragment to both main group and transition metal centers. This unique reactivity has led to the preparation of unusual species such as singlet carbene \u003cstrong\u003eA\u003c/strong\u003e and \u003cstrong\u003eB\u003c/strong\u003e-\u003cstrong\u003eE\u003c/strong\u003e (Fig. 1b). In our previous work, we isolated a copper phosphinocarbyne anion complex \u003cstrong\u003eE\u003c/strong\u003e by employing a bulky phosphino substituent.\u003csup\u003e38\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eComplementary computational studies conducted by Su have shed light on the properties of stannynes and suggested that appropriate bulky substituents can encapsulate the central C\u0026equiv;Sn unit, protecting it and enabling its isolation as a stable species.\u003csup\u003e29\u003c/sup\u003e Herein, we demonstrate the isolation of a base-free crystalline stannyne via the strategic combination of a bulky cyclic phosphino and a bulky terphenyl substituent. This species represents an example of a base-free heteronuclear analog of alkynes containing a heavier group 14 element, and it is also the unprecedented main group species to possess diverse adjacent ambiphilic centers. This work has significant implications for the future design of adjacent bis-ambiphile main group systems.\u003c/p\u003e"},{"header":"Results and Discussion","content":"\u003cp\u003e\u003cstrong\u003eSynthesis and characterization\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn our pursuit of a stannyne, we aimed to introduce a π-donor substituent at the carbon center. This substitution has proven to effectively stabilize the singlet state of low-valent carbon species.\u003csup\u003e39,40\u003c/sup\u003e Additionally, increasing the steric bulk of the substituents at both carbon and tin atoms would provide desirable kinetic protection.\u003csup\u003e5\u003c/sup\u003e To achieve this goal, we synthesized a stannylenyl diazomethane \u003cstrong\u003e2\u003c/strong\u003e (\u003csup\u003e31\u003c/sup\u003eP NMR: 125.5 ppm) as a precursor, bearing a bulky cyclic phosphino at the carbon center and a bulky terphenyl substituent at the tin center (Fig. 2). This compound was prepared by treating \u003cstrong\u003e1\u003c/strong\u003e\u003csup\u003e37\u003c/sup\u003e with potassium \u003cem\u003etert\u003c/em\u003e-butoxide (\u003cem\u003e\u003csup\u003et\u003c/sup\u003e\u003c/em\u003eBuOK) in THF followed by 2,6-Mes\u003csub\u003e2\u003c/sub\u003eC\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003eSnCl\u003csup\u003e41\u003c/sup\u003e (Mes = mesityl) in the absence of light. The infrared absorption ν(CN\u003csub\u003e2\u003c/sub\u003e) in \u003cstrong\u003e2\u003c/strong\u003e occurs at 1966 cm\u003csup\u003e–1\u003c/sup\u003e, showing similarity to the corresponding absorption observed in metal-substituted phosphinodiazaomethanes.\u003csup\u003e37,38\u003c/sup\u003e Yellow single crystals of \u003cstrong\u003e2\u003c/strong\u003e were obtained by slowly evaporating its concentrated pentane solution at\u0026nbsp;–30 ℃, and its\u0026nbsp;structure was confirmed by X-ray diffraction (Fig. 3a).\u003c/p\u003e\n\u003cp\u003eWe observed an intriguing phenomenon whereby N\u003csub\u003e2\u003c/sub\u003e was gradually eliminated from a C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e solution of \u003cstrong\u003e2\u003c/strong\u003e at room temperature over a period of approximately 7 hours (Supplementary Fig. S17). This elimination was concurrent with the intensity loss of the infrared ν(CN\u003csub\u003e2\u003c/sub\u003e) absorption, affording\u0026nbsp;species \u003cstrong\u003e3\u003c/strong\u003e. Alternatively, irradiating (303 nm) a solid of \u003cstrong\u003e2\u0026nbsp;\u003c/strong\u003eat room temperature for 30 minutes followed by washing with cold pentane resulted in the isolation of \u003cstrong\u003e3\u003c/strong\u003e as a yellow solid with a 96% yield (217 mg, 0.254 mmol). The \u003csup\u003e31\u003c/sup\u003eP NMR resonance of \u003cstrong\u003e3\u003c/strong\u003e displays a singlet at 67.9 ppm accompanied by a satellite doublet arising from the P-Sn coupling (168.7 Hz).\u0026nbsp;Meanwhile, its\u0026nbsp;\u003csup\u003e119\u003c/sup\u003eSn NMR signal shows a doublet at 1149.3 ppm\u0026nbsp;(168.7 Hz). This stands in stark contrast to the spectroscopic characteristics of \u003cstrong\u003e2\u003c/strong\u003e, where no two-bond P-Sn coupling was observed and singlet resonances were detected in both the \u003csup\u003e31\u003c/sup\u003eP (125.3 ppm) and \u003csup\u003e119\u003c/sup\u003eSn NMR (92.7 ppm) spectra.\u003c/p\u003e\n\u003cp\u003eSurprisingly, we found that \u003cstrong\u003e3\u003c/strong\u003e was exceptionally stable in both its solid and solution states at room temperature and could be safely stored for several months in a glove box with a nitrogen atmosphere. However, it should be noted that \u003cstrong\u003e3\u003c/strong\u003e is sensitive to air and gradually decomposes into unknown substances in 1 h (Supplementary Fig. S22). The electronic spectrum of \u003cstrong\u003e3\u003c/strong\u003e reveals the presence of two broad absorption bands, ranging from 320 to 360 nm and 400 to 480 nm (Supplementary Fig. S60), which are responsible for its characteristic yellow color. Time-dependent density functional theory (TD-DFT) calculations indicate that these bands originate from HOMO to LUMO and HOMO–1 to LUMO transitions, respectively (Supplementary Fig. S71).\u003c/p\u003e\n\u003cp\u003eCompound \u003cstrong\u003e3\u003c/strong\u003e crystalized as yellow crystals from a concentrated pentane solution at –30 ℃, and its X-ray diffraction analysis confirmed its formulation as [(CH\u003csub\u003e2\u003c/sub\u003e)(NDipp)]\u003csub\u003e2\u003c/sub\u003ePCSn(C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e-2,6-Mes) (Dipp = 2,6-diisopropylphenyl; Mes = mesityl) (Fig. 3b). In contrast to the pyramidalization observed at P(1) in \u003cstrong\u003e2\u0026nbsp;\u003c/strong\u003e(Fig.3a), the P(1) atom of \u003cstrong\u003e3\u003c/strong\u003e adopts a trigonal planar geometry with a sum of angles of 358.6°. Notably, the P(1)−C(1) bond in \u003cstrong\u003e3\u003c/strong\u003e is significantly shortened (1.561(6) Å) compared to that of \u003cstrong\u003e2\u003c/strong\u003e (1.879(8) Å), indicating strong P-to-C π-donation and resulting in multiple bond character. This is similar to observations in Bertrand’s (phosphino)(silyl)carbene Me\u003csub\u003e2\u003c/sub\u003eSi(\u003cem\u003e\u003csup\u003et\u003c/sup\u003e\u003c/em\u003eBuN)\u003csub\u003e2\u003c/sub\u003ePCSiMe\u003csub\u003e3\u003c/sub\u003e\u003csup\u003e42\u003c/sup\u003e and our copper phosphinocarbyne anion complex [(CH\u003csub\u003e2\u003c/sub\u003e)(NDipp)]\u003csub\u003e2\u003c/sub\u003ePCCu(IPent) (IPent = 1,3-bis(2,6-di(3-pentyl)phenyl)imidazol-2-ylidene).\u003csup\u003e38\u003c/sup\u003e Additionally, the C(1)−Sn(1) bond length in \u003cstrong\u003e3\u003c/strong\u003e (2.082(6) Å) is shortened relative to \u003cstrong\u003e2\u003c/strong\u003e (2.134(8) Å) and lies between Pyykkö’s standard values for C−Sn single (2.15 Å) and double bonds (1.97 Å).\u003csup\u003e43\u003c/sup\u003e For comparison, the Sn(1)−C(2) bond length in \u003cstrong\u003e3\u003c/strong\u003e is 2.217(5) Å. These data indicate the presence of a multiple bond between C(1) and Sn(1) in \u003cstrong\u003e3\u003c/strong\u003e. The bond angles of P(1)−C(1)−Sn(1) (136.7(3)°) and C(1)−Sn(1)−C(2) (98.0(2)°) in \u003cstrong\u003e3\u003c/strong\u003e are slightly more acute than those in \u003cstrong\u003e2\u003c/strong\u003e (138.0(5) and 105.6(5)°, respectively).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComputational studies\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe conducted quantum chemical calculations to elucidate the electronic structure of compound \u003cstrong\u003e3\u003c/strong\u003e. The optimized structural parameters of \u003cstrong\u003e3\u003c/strong\u003e obtained at the BP86-D3(BJ)/def2-TZVPP level of theory are in good agreement with the X-ray data (Supplementary Table 7). NBO analysis (BP86-D3(BJ)/def2-TZVPP) revealed that P(1) (1.59 a.u.) and Sn(1) (1.09 a.u.) atoms carry considerable positive charges, while C(1) (–1.45 a.u.) and C(2) (–0.39 a.u.) atoms are negatively charged. This charge separation is due to the lower electronegativity of phosphorus (2.19) and tin (1.96) compared to nitrogen (3.04) and carbon (2.55) elements.\u003c/p\u003e\n\u003cp\u003eFurthermore, the Wiberg bond indexes (WBIs) of P(1)−C(1), C(1)−Sn(1), and Sn(1)−C(2) are 2.08, 0.80, and 0.60, respectively. These values indicate a pronounced multiple bond character for P(1)−C(1) and a relatively stronger bonding interaction between C(1) and Sn(1) than between Sn(1) and C(2). Notably, the WBI for the C(1)−Sn(1) bond in \u003cstrong\u003e3\u003c/strong\u003e (0.80) is slightly higher compared to those in \u003cstrong\u003e5\u003c/strong\u003e (0.77) and \u003cstrong\u003e6\u003c/strong\u003e (0.72) (vide infra) (Supplementary Table 8). This distinction can be attributed to the absence of a lone pair and a vacant 5p orbital at Sn(1) in \u003cstrong\u003e5\u0026nbsp;\u003c/strong\u003eand \u003cstrong\u003e6\u003c/strong\u003e, which mitigates the extent of π-interaction with adjacent atoms (vide infra). It is important to acknowledge, however, that WBI values may not always precisely reflect the nature of multiple bonds, especially those with high ionic character, as exemplified by the relatively low WBI (0.89) of an Al−N triple bond in an iminoalane.\u003csup\u003e44\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eTo gain further insights into the bonding situation of \u003cstrong\u003e3\u003c/strong\u003e, frontier molecular orbital (FMO), intrinsic bond orbital (IBO)\u003csup\u003e45,46\u003c/sup\u003e and electron localization function (ELF)\u003csup\u003e47\u003c/sup\u003e calculations were carried out (Fig. 4 and Supplementary Fig. S67). The HOMO (–4.47 eV) consists of the P(1)−C(1) π-bonding orbital and the lone pair orbital at Sn(1) (Fig. 4a). The HOMO–1 (–4.94 eV) corresponds to the P(1)−C(1)−Sn(1) out-of-plane 3-center-2-electron (3c2e) π-bonding orbital (Fig. 4b). Further, the HOMO–2 level, at –5.40 eV, is primarily composed of a slipped C(1)−Sn(1) π bond, exhibiting lone pair characteristics at both C(1) and Sn(1) (Fig. 4c). This form of slipped π bond contributes to the bent geometry observed at C(1) and is a feature commonly associated with heavier main group elements forming multiple bonds,\u003csup\u003e7-9\u003c/sup\u003e as seen in disilyne,\u003csup\u003e2\u003c/sup\u003e digermyne,\u003csup\u003e4\u003c/sup\u003e distannyne,\u003csup\u003e5\u003c/sup\u003e and diplumbyne.\u003csup\u003e6\u003c/sup\u003e Moreover, the LUMO (–2.01 eV) represents a C(1)−Sn(1) π*-antibonding orbital with a significant vacant 5p orbital character at Sn(1), along with the P−N σ*-antibonding orbitals (Fig. 4d). The LUMO+2 (–1.45 eV) features the P(1)−C(1) π*-antibonding orbital (Fig. 4e). Overall, this FMO analysis reveals the multiple bond character of the P(1)−C(1)−Sn(1) chain in \u003cstrong\u003e3\u003c/strong\u003e (see resonance forms in Fig. 2) and suggests that both C(1) and Sn(1) exhibit ambiphilicity. Notably, the ELF plot of \u003cstrong\u003e3\u003c/strong\u003e shows the ionic interaction between the C and Sn atoms in the P(1)−C(1)−Sn(1) plane, with limited electron density localized at the C(1)−Sn(1) and Sn(1)−C(2) bonds (Fig. 4f), whereas the P(1)−C(1) bond exhibits a strong covalent character.\u003c/p\u003e\n\u003cp\u003eOur IBO analysis indicates that C(1) forms two σ bonds, one each with P(1) and Sn(1) (\u003cstrong\u003eIBO1\u003c/strong\u003e and \u003cstrong\u003eIBO5\u003c/strong\u003e, Supplementary Fig. S67). Additionally, there is a slipped P(1)−C(1) π bond (\u003cstrong\u003eIBO2\u003c/strong\u003e), arising from the donation of a lone pair by P(1). The lone pair on Sn(1) remains highly localized (\u003cstrong\u003eIBO4\u003c/strong\u003e), while \u003cstrong\u003eIBO3\u003c/strong\u003e illustrates a 3c2e π bond centered at C(1), consistent with the HOMO–1 of \u003cstrong\u003e3\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eNatural resonance theory (NRT) calculations on a simplified model of \u003cstrong\u003e3\u003c/strong\u003e (where Dipp groups are replaced by H atoms and the Ter group by a CH\u003csub\u003e3\u003c/sub\u003e), the predominant resonance form is identified as the allenic structure (26.65%) (Supplementary Figure S68). Other significant resonance forms include P(1)−C(1)=Sn(1) (11.02%) and P(1)−C(1)≡Sn(1) (5.35%), along with two forms of P(1)≡C(1)−Sn(1) contributing 10.33% and 7.67%, respectively. Taken together, these results, combined with the FMO and IBO findings, suggest that the electronic structure of \u003cstrong\u003e3\u003c/strong\u003e is most appropriately represented as an allenic structure \u003cstrong\u003e3A\u003c/strong\u003e. This structure is characterized by considerable π-electron delocalization across the P(1)−C(1)−Sn(1) atoms, with P bearing a formal positive charge and Sn a negative charge. Despite an allenic structure of \u003cstrong\u003e3\u003c/strong\u003e, both NRT and FMO analyses (HOMO–1 and HOMO–2) suggest a minor contribution of the stannye form of P(1)−C(1)≡Sn(1).\u003c/p\u003e\n\u003cp\u003eA salient structural characteristic of \u003cstrong\u003e3\u003c/strong\u003e is the near-perpendicular orientation of the N(1)−P(1)−N(2) plane to the P(1)−C(1)−Sn(1) plane (Fig. 3b). The trigonal-planar configuration of the phosphino moiety exhibits a pronounced twist relative to the P(1)−C(1)−Sn(1) plane, indicated by a torsion angle of –97.9(6)° for N(1)−P(1)−C(1)−Sn(1). Notably, this angle exceeds those reported for germmyne \u003cstrong\u003eC\u003c/strong\u003e,\u003csup\u003e32\u003c/sup\u003e which has a torsion angle of –73.6(6)°, and the methylenephosphonium salt [(\u003cem\u003e\u003csup\u003ei\u003c/sup\u003e\u003c/em\u003ePr\u003csub\u003e2\u003c/sub\u003eN)\u003csub\u003e2\u003c/sub\u003eP=C(TMS)\u003csub\u003e2\u003c/sub\u003e][OTf], with a torsion angle of –59.5(3)°.\u003csup\u003e48\u003c/sup\u003e The distinct spatial configuration observed in \u003cstrong\u003e3\u003c/strong\u003e can be largely attributed to π-interactions. These interactions involve the lone pairs present on P(1) and Sn(1) and the formally unoccupied p orbital on C(1). Furthermore, the delocalization of the C(1) lone pair into the vacant p orbital of Sn(1) and into the N−P σ* antibonding orbitals plays a significant role (Supplementary Fig. S66). This type of out-of-plane negative hyperconjugation, emanating from the C(1) lone pair to the N−P σ* antibonding orbitals, is in line with stabilization approaches for a unique carbene with a σ\u003csup\u003e0\u003c/sup\u003eπ\u003csup\u003e2\u003c/sup\u003e electronic configuration.\u003csup\u003e49\u003c/sup\u003e Upon performing a constrained geometry optimization, it has been determined that the alternative co-planar conformation is energetically disfavored by 4.2 kcal/mol relative to the experimentally observed structure of \u003cstrong\u003e3\u003c/strong\u003e (Supplementary Fig. S65).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eReactivity\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDiarylstannylene with electron-withdrawing aryl substituents reacts with isocyanide, forming Lewis acid-base adducts.\u003csup\u003e50,51\u003c/sup\u003e However, treatment of \u003cstrong\u003e3\u003c/strong\u003e with 1-adamantyl isocyanide (AdNC) at room temperature yields the sole product \u003cstrong\u003e4\u003c/strong\u003e (\u003csup\u003e31\u003c/sup\u003eP NMR: 112.2 ppm; \u003csup\u003e119\u003c/sup\u003eSn NMR: 1486.9 ppm) (Fig. 5), regardless of the amount of AdNC used. Through multi-nuclear NMR and X-ray diffraction data, \u003cstrong\u003e4\u003c/strong\u003e is identified as a (phosphino)(stannylenyl)ketenimine with the stannylene center remaining intact (Fig. 6a). This reaction demonstrates the synthetic potential of stannynes for unique stannylenes with unconventional substituents.\u003csup\u003e52\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eThe stannyne \u003cstrong\u003e3\u003c/strong\u003e not only functions as a carbene but also exhibits properties of stannylene. While the [4+1] cycloaddition of stannylenes with dienes is typically limited to stannylenes with electropositive substituents like germyl\u003csup\u003e53\u003c/sup\u003e and boryl,\u003csup\u003e54\u003c/sup\u003e the addition of excess 2,3-dimethyl-1,3-butadiene to a THF solution of \u003cstrong\u003e3\u003c/strong\u003e generates species \u003cstrong\u003e5\u0026nbsp;\u003c/strong\u003e(\u003csup\u003e31\u003c/sup\u003eP NMR:\u0026nbsp;3.7\u0026nbsp;ppm; \u003csup\u003e119\u003c/sup\u003eSn NMR: –43.6\u0026nbsp;ppm) (Fig. 5). Isolation of \u003cstrong\u003e5\u003c/strong\u003e as colorless X-ray quality crystals in 65% yield confirms its formulation as a (phosphino)(stannyl)carbene (Fig. 6b). Contrasting with \u003cstrong\u003e3\u003c/strong\u003e, the phosphino group in \u003cstrong\u003e5\u003c/strong\u003e adopts a co-planar arrangement concerning the P(1)−C(1)−Sn(1) plane. This structural arrangement can be attributed to the absence of a lone pair and an unoccupied 5p orbital at Sn(1) in \u003cstrong\u003e5\u003c/strong\u003e. It is noteworthy that (phosphino)(stannyl)carbenes were previously considered reactive intermediates incapable of isolation,\u003csup\u003e55\u003c/sup\u003e making \u003cstrong\u003e5\u003c/strong\u003e the first example of its kind. This reaction highlights the versatility of stannynes as a versatile synthon for novel carbenes with unusual substituents.\u003csup\u003e40\u003c/sup\u003e To the best of our knowledge, \u003cstrong\u003e3\u003c/strong\u003e represents the first example of a main group compound with diverse adjacent ambiphilic centers.\u003c/p\u003e\n\u003cp\u003eWe then investigated the reactivity of the C(1)−Sn(1) multiple bonding character in \u003cstrong\u003e3\u003c/strong\u003e. When \u003cstrong\u003e3\u003c/strong\u003e was treated with dry HCl in dioxane, a complex mixture was observed. Nonetheless, addition reactions of \u003cstrong\u003e3\u003c/strong\u003e with excess Et\u003csub\u003e3\u003c/sub\u003eN·HCl at –35 \u003csup\u003eo\u003c/sup\u003eC, a mild Brønsted acid, proceeded smoothly, giving rise to the formation of \u003cstrong\u003e6\u003c/strong\u003e (\u003csup\u003e31\u003c/sup\u003eP NMR:\u0026nbsp;111.3\u0026nbsp;ppm; \u003csup\u003e119\u003c/sup\u003eSn NMR: –13.2\u0026nbsp;ppm). X-ray diffraction analysis confirmed that \u003cstrong\u003e6\u003c/strong\u003e is a double addition product, with two hydrogen atoms and two chlorine atoms attached to C(1) and Sn(1), respectively (Figure 6c). The C(1)−Sn(1) bond length in \u003cstrong\u003e6\u003c/strong\u003e elongates to 2.126(4) Å compared to 2.082(6) Å in \u003cstrong\u003e3\u003c/strong\u003e. By adjusting the reaction ratio of \u003cstrong\u003e3\u003c/strong\u003e:Et\u003csub\u003e3\u003c/sub\u003eN·HCl to 1:1, we observed the formation of \u003cstrong\u003e6\u003c/strong\u003e as well as a major intermediate (\u003csup\u003e31\u003c/sup\u003eP NMR:\u0026nbsp;90.7\u0026nbsp;ppm), along with unreacted \u003cstrong\u003e3\u0026nbsp;\u003c/strong\u003e(Supplementary Fig. S35). Although we were unable to isolate the intermediate, our calculations suggest that it is likely the monoaddition intermediate, specifically the stannaalkene [(CH\u003csub\u003e2\u003c/sub\u003e)(NDipp)]\u003csub\u003e2\u003c/sub\u003ePC(H)=Sn(Cl)(C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e-2,6-Mes) (calc. \u003csup\u003e31\u003c/sup\u003eP NMR: 97.6 ppm, Supplementary Figure S72) (for a proposed mechanism, refer to Supplementary Fig. S61).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn comparison, our experiments with a previous copper carbyne anion complex demonstrated that protonation of the [(CH\u003csub\u003e2\u003c/sub\u003e)(NDipp)]\u003csub\u003e2\u003c/sub\u003ePC\u003csup\u003e–\u003c/sup\u003e anion produced a transient monosubstituted carbene, spontaneously dimerizing into the alkene [(CH\u003csub\u003e2\u003c/sub\u003e)(NDipp)]\u003csub\u003e2\u003c/sub\u003eP(H)C=C(H)P[(NDipp)(CH\u003csub\u003e2\u003c/sub\u003e)]\u003csub\u003e2\u003c/sub\u003e.\u003csup\u003e38\u003c/sup\u003e However, when treating \u003cstrong\u003e3\u003c/strong\u003e with an equivalent of Et\u003csub\u003e3\u003c/sub\u003eN·HCl, the same alkene did not form, implying a minimal contribution from the stannyliumylidene resonance form (i.e. a complex of [(CH\u003csub\u003e2\u003c/sub\u003e)(NDipp)]\u003csub\u003e2\u003c/sub\u003ePC\u003csup\u003e–\u003c/sup\u003e anion and [(C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e-2,6-Mes)Sn]\u003csup\u003e+\u003c/sup\u003e cation).\u003c/p\u003e\n\u003cp\u003eRemarkably, \u003cstrong\u003e3\u003c/strong\u003e exhibited a facile reaction involving cleavage of the C−Sn bond when treated with isopropyl isocyanate (\u003cem\u003e\u003csup\u003ei\u003c/sup\u003e\u003c/em\u003ePrNCO) (Fig. 5). The reaction, conducted with either one or two equivalents of \u003cem\u003e\u003csup\u003ei\u003c/sup\u003e\u003c/em\u003ePrNCO, predominantly produced \u003cstrong\u003e7\u003c/strong\u003e, while in the former case a portion of \u003cstrong\u003e3\u003c/strong\u003e remained unchanged. In the \u003csup\u003e31\u003c/sup\u003eP and \u003csup\u003e119\u003c/sup\u003eSn NMR spectra of \u003cstrong\u003e7\u003c/strong\u003e, singlet resonances were observed at 15.7 and 342.9 ppm, respectively. To our surprise, single-crystal X-ray diffraction analysis of colorless crystals of \u003cstrong\u003e7\u003c/strong\u003e revealed complete splitting of the C−Sn bond through the formal insertion of two \u003cem\u003e\u003csup\u003ei\u003c/sup\u003e\u003c/em\u003ePrNCO molecules, accompanied by rearrangement involving H- and O-shifts (Figure 6d) (for a proposed mechanism, refer to Supplementary Fig. S63). This O-migration bears resemblance to the rearrangement observed in phosphaketenes to phosphaheteroallenes.\u003csup\u003e56\u003c/sup\u003e\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eMore than two decades after Power's groundbreaking work on distannyne\u003csup\u003e5\u003c/sup\u003e and a decade following the seminal contributions of Kato and Baceiredo in base-stabilized silyne and germyne,\u003csup\u003e31,32\u003c/sup\u003e the isolation of \u003cstrong\u003e3\u003c/strong\u003e stands as a testament to the feasibility of stabilizing base-free stannynes at room temperature. Compound \u003cstrong\u003e3\u003c/strong\u003e, featuring adjacent ambiphilic carbon and tin atoms, represents an unprecedented example of a main group species with such diverse ambiphilic centers. It showcases a carbon-tin multiple bond with ionic characteristics. Intriguingly, this stannyne can act as either a singlet carbene or a stannylene depending on the substrates involved, highlighting its versatility as a precursor for unique carbenes and stannylenes. Given the substantial impact of alkynes and their heavier homonuclear analogs across various disciplines, we believe that with continued development and research, their heteronuclear heavier counterparts will similarly find widespread applications in a variety of fields.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe gratefully acknowledge financial support from the National Natural Science Foundation of China (22350004; 22271132; 22101114), Shenzhen Science and Technology Innovation Program (JCYJ20220530114806015), Guangdong Innovation \u0026amp; Entrepreneurial Research Team Program (2021ZT09C278), and Guangdong Provincial Key Laboratory of Catalysis (2020B121201002). We also acknowledge the assistance of SUSTech Core Research Facilities. The theoretical work was supported by the Center for Computational Science and Engineering at SUSTech.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eL.L.L. conceptualized and supervised the project. X.F.W. and R.W. performed the experimental work. L.L.L., X.F.W., C.H, and R.W. performed the computational work. X.F.W., C.P.H., J.C.L., R.W. and X.Z. performed the X-ray crystallographic analyses. L.L.L. wrote the paper with the input from all authors. All authors discussed the results in detail and commented on the paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eDiederich, F. \u0026amp; Stang, P. J. \u003cem\u003eModern acetylene chemistry\u003c/em\u003e. (John Wiley \u0026amp; Sons, 2008).\u003c/li\u003e\n\u003cli\u003eSekiguchi, A., Kinjo, R. \u0026amp; Ichinohe, M. A stable compound containing a silicon-silicon triple bond. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e305\u003c/strong\u003e, 1755-1757 (2004).\u003c/li\u003e\n\u003cli\u003eWiberg, N., Vasisht, S. K., Fischer, G. \u0026amp; Mayer, P. Disilynes. III [1] A relatively stable disilyne RSi\u0026equiv;SiR (R = SiMe(SitBu\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e). \u003cem\u003eZ. Anorg. Allg. Chem.\u003c/em\u003e \u003cstrong\u003e630\u003c/strong\u003e, 1823-1828 (2004).\u003c/li\u003e\n\u003cli\u003eStender, M., Phillips, A. D., Wright, R. J. \u0026amp; Power, P. P. Synthesis and characterization of a digermanium analogue of an alkyne. \u003cem\u003eAngew. Chem., Int. Ed.\u003c/em\u003e \u003cstrong\u003e41\u003c/strong\u003e, 1785-1787 (2002).\u003c/li\u003e\n\u003cli\u003ePhillips, A. D., Wright, R. J., Olmstead, M. M. \u0026amp; Power, P. P. Synthesis and characterization of 2,6-Dipp\u003csub\u003e2\u003c/sub\u003e-H\u003csub\u003e3\u003c/sub\u003eC\u003csub\u003e6\u003c/sub\u003eSnSnC\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e-2,6-Dipp\u003csub\u003e2\u003c/sub\u003e (Dipp = C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e-2,6-Pri\u003csub\u003e2\u003c/sub\u003e):\u0026thinsp; a tin analogue of an alkyne. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e124\u003c/strong\u003e, 5930-5931 (2002).\u003c/li\u003e\n\u003cli\u003ePu, L., Twamley, B. \u0026amp; Power, P. P. Synthesis and characterization of 2,6-Trip\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003eC\u003csub\u003e6\u003c/sub\u003ePbPbC\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e-2,6-Trip\u003csub\u003e2\u003c/sub\u003e (Trip = C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e2\u003c/sub\u003e-2,4,6-i-Pr\u003csub\u003e3\u003c/sub\u003e):\u0026thinsp; a stable heavier group 14 element analogue of an alkyne. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e122\u003c/strong\u003e, 3524-3525 (2000).\u003c/li\u003e\n\u003cli\u003ePower, P. P. Main-group elements as transition metals. \u003cem\u003eNature\u003c/em\u003e \u003cstrong\u003e463\u003c/strong\u003e, 171-177 (2010).\u003c/li\u003e\n\u003cli\u003eFischer, R. C. \u0026amp; Power, P. P. \u0026pi;-Bonding and the lone pair effect in multiple bonds involving heavier main group elements: developments in the new millennium. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e110\u003c/strong\u003e, 3877-3923 (2010).\u003c/li\u003e\n\u003cli\u003ePower, P. P. An Update on multiple bonding between heavier main group elements: the importance of pauli repulsion, charge-shift character, and london dispersion force effects. \u003cem\u003eOrganometallics\u003c/em\u003e \u003cstrong\u003e39\u003c/strong\u003e, 4127-4138 (2020).\u003c/li\u003e\n\u003cli\u003eSekiguchi, A. Disilyne with a silicon-silicon triple bond: a new entry to multiple bond chemistry. \u003cem\u003ePure Appl. Chem.\u003c/em\u003e \u003cstrong\u003e80\u003c/strong\u003e, 447-457 (2008).\u003c/li\u003e\n\u003cli\u003ePower, P. P. Silicon, germanium, tin and lead analogues of acetylenes. \u003cem\u003eChem. Commun.\u003c/em\u003e \u003cstrong\u003e38\u003c/strong\u003e, 2091-2101 (2003).\u003c/li\u003e\n\u003cli\u003eSugiyama, Y.\u003cem\u003e et al.\u003c/em\u003e Synthesis and properties of a new kinetically stabilized digermyne:\u0026thinsp; new insights for a germanium analogue of an alkyne. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e128\u003c/strong\u003e, 1023-1031 (2006).\u003c/li\u003e\n\u003cli\u003eLai, T. Y., Tao, L., Britt, R. D. \u0026amp; Power, P. P. Reversible Sn\u0026ndash;Sn triple bond dissociation in a distannyne: support for charge-shift bonding character. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e141\u003c/strong\u003e, 12527-12530 (2019).\u003c/li\u003e\n\u003cli\u003eQueen, J. D., Phung, A. C., Caputo, C. A., Fettinger, J. C. \u0026amp; Power, P. P. Metathetical exchange between metal\u0026ndash;metal triple bonds. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e142\u003c/strong\u003e, 2233-2237 (2020).\u003c/li\u003e\n\u003cli\u003eDing, Y., Zhang, J., Li, Y. \u0026amp; Cui, C. Disilicon dicarbonyl complex: synthesis and protonation of CO with O\u0026ndash;H bond. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e144\u003c/strong\u003e, 20566-20570 (2022).\u003c/li\u003e\n\u003cli\u003eBader, R. F. W. Vibrationally induced perturbations of molecular electron distribution. \u003cem\u003eCan. J. Chem.\u003c/em\u003e \u003cstrong\u003e40\u003c/strong\u003e, 1164-1175 (1962).\u003c/li\u003e\n\u003cli\u003ePearson, R. G. Symmetry rule for predicting molecular structure and reactivity. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e91\u003c/strong\u003e, 1252-1254 (1969).\u003c/li\u003e\n\u003cli\u003ePearson, R. G. Concerning Jahn-Teller effects. \u003cem\u003eProc. Natl. Acad. Sci. U. S. A.\u003c/em\u003e \u003cstrong\u003e72\u003c/strong\u003e, 2104-2106 (1975).\u003c/li\u003e\n\u003cli\u003eGrev, R. S. Structure and bonding in the parent hydrides and multiply bonded silicon and germanium compounds: from MHn to R\u003csub\u003e2\u003c/sub\u003eM=M\u0026apos;R\u003csub\u003e2\u003c/sub\u003e and RM\u0026equiv;M\u0026apos;R. \u003cem\u003eAdv. Organomet. Chem.\u003c/em\u003e \u003cstrong\u003e33\u003c/strong\u003e, 125-170 (1991).\u003c/li\u003e\n\u003cli\u003ePower, P. P. Interaction of multiple bonded and unsaturated heavier main group compounds with hydrogen, ammonia, olefins, and related molecules. \u003cem\u003eAcc. Chem. Res.\u003c/em\u003e \u003cstrong\u003e44\u003c/strong\u003e, 627-637 (2011).\u003c/li\u003e\n\u003cli\u003ePeng, Y., Ellis, B. D., Wang, X., Fettinger, J. C. \u0026amp; Power, P. P. Reversible reactions of ethylene with distannynes under ambient conditions. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e325\u003c/strong\u003e, 1668-1670 (2009).\u003c/li\u003e\n\u003cli\u003eMelen, R. L. Frontiers in molecular p-block chemistry: from structure to reactivity. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e363\u003c/strong\u003e, 479-484 (2019).\u003c/li\u003e\n\u003cli\u003eSpikes, G. H., Fettinger, J. C. \u0026amp; Power, P. P. Facile activation of dihydrogen by an unsaturated heavier main group compound. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e127\u003c/strong\u003e, 12232-12233 (2005).\u003c/li\u003e\n\u003cli\u003eApeloig, Y. \u0026amp; Karni, M. Triple bonds to silicon. Substituent effects on the thermodynamic and kinetic stabilities of silynes relative to their isomeric silylidenes and silavinylidenes. \u003cem\u003eOrganometallics\u003c/em\u003e \u003cstrong\u003e16\u003c/strong\u003e, 310-312 (1997).\u003c/li\u003e\n\u003cli\u003eDanovich, D.\u003cem\u003e et al.\u003c/em\u003e Silynes (RC\u0026equiv;SiR\u0026prime;) and disilynes (RSi\u0026equiv;SiR\u0026prime;): why are less bonds worth energetically more? \u003cem\u003eAngew. Chem., Int. Ed.\u003c/em\u003e \u003cstrong\u003e40\u003c/strong\u003e, 4023-4026 (2001).\u003c/li\u003e\n\u003cli\u003eBibal, C., Mazi\u0026egrave;res, S., Gornitzka, H. \u0026amp; Couret, C. A route to a germanium\u0026ndash;carbon triple bond: first chemical evidence for a germyne. \u003cem\u003eAngew. Chem., Int. Ed.\u003c/em\u003e \u003cstrong\u003e40\u003c/strong\u003e, 952-954 (2001).\u003c/li\u003e\n\u003cli\u003eWu, P.-C. \u0026amp; Su, M.-D. Theoretical designs for germaacetylene (RCGeR\u0026prime;): a new target for synthesis. \u003cem\u003eDalton Trans.\u003c/em\u003e \u003cstrong\u003e40\u003c/strong\u003e, 4253-4259 (2011).\u003c/li\u003e\n\u003cli\u003ePloshnik, E., Danovich, D., Hiberty, P. C. \u0026amp; Shaik, S. The nature of the idealized triple bonds between principal elements and the \u0026sigma; origins of trans-bent geometries\u0026mdash;a valence bond study. \u003cem\u003eJ. Chem. Theory Comput.\u003c/em\u003e \u003cstrong\u003e7\u003c/strong\u003e, 955-968 (2011).\u003c/li\u003e\n\u003cli\u003eWu, P.-C. \u0026amp; Su, M.-D. Triply bonded stannaacetylene (RC\u0026equiv;SnR): theoretical designs and characterization. \u003cem\u003eInorg. Chem.\u003c/em\u003e \u003cstrong\u003e50\u003c/strong\u003e, 6814-6822 (2011).\u003c/li\u003e\n\u003cli\u003eWu, P.-C. \u0026amp; Su, M.-D. A new target for synthesis of triply bonded plumbacetylene (RC\u0026equiv;PbR): a theoretical design. \u003cem\u003eOrganometallics\u003c/em\u003e \u003cstrong\u003e30\u003c/strong\u003e, 3293-3301 (2011).\u003c/li\u003e\n\u003cli\u003eGau, D.\u003cem\u003e et al.\u003c/em\u003e Synthesis and structure of a base-stabilized C-phosphino-Si-amino silyne. \u003cem\u003eAngew. Chem., Int. Ed.\u003c/em\u003e \u003cstrong\u003e49\u003c/strong\u003e, 6585-6588 (2010).\u003c/li\u003e\n\u003cli\u003eBerthe, J.\u003cem\u003e et al.\u003c/em\u003e Synthesis and reactivity of a phosphine-stabilized monogermanium analogue of alkynes. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e133\u003c/strong\u003e, 15930-15933 (2011).\u003c/li\u003e\n\u003cli\u003eTakahashi, S.\u003cem\u003e et al.\u003c/em\u003e Base-stabilized cationic silyne with a \u0026pi;-accepting phosphonio substituent. \u003cem\u003eInorg. Chem.\u003c/em\u003e \u003cstrong\u003e62\u003c/strong\u003e, 6488-6498 (2023).\u003c/li\u003e\n\u003cli\u003eSetaka, W., Hirai, K., Tomioka, H., Sakamoto, K. \u0026amp; Kira, M. Stannaacetylene (RSn⋮CR\u0026apos;) showing carbene-like reaction mode. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e126\u003c/strong\u003e, 2696-2697 (2004).\u003c/li\u003e\n\u003cli\u003eSetaka, W., Hirai, K., Tomioka, H., Sakamoto, K. \u0026amp; Kira, M. Formation of a stannylstannylenevia intramolecular carbene addition of a transient stannaacetylene (RSnCR\u0026prime;). \u003cem\u003eChem. Commun.\u003c/em\u003e \u003cstrong\u003e43\u003c/strong\u003e, 6558-6560 (2008).\u003c/li\u003e\n\u003cli\u003eIgau, A., Grutzmacher, H., Baceiredo, A. \u0026amp; Bertrand, G. Analogous \u0026alpha;,\u0026alpha;\u0026apos;-bis-carbenoid, triply bonded species: synthesis of a stable \u0026gamma;3-phosphino carbene-\u0026gamma;5-phosphaacetylene. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e110\u003c/strong\u003e, 6463-6466 (1988).\u003c/li\u003e\n\u003cli\u003eHu, C.\u003cem\u003e et al.\u003c/em\u003e Crystalline monometal-substituted free carbenes. \u003cem\u003eChem\u003c/em\u003e \u003cstrong\u003e8\u003c/strong\u003e, 2278-2289 (2022).\u003c/li\u003e\n\u003cli\u003eWei, R., Wang, X.-F., Hu, C. \u0026amp; Liu, L. L. Synthesis and reactivity of copper carbyne anion complexes. \u003cem\u003eNat. Synth.\u003c/em\u003e \u003cstrong\u003e2\u003c/strong\u003e, 357-363 (2023).\u003c/li\u003e\n\u003cli\u003eBourissou, D., Guerret, O., Gabba\u0026iuml;, F. P. \u0026amp; Bertrand, G. Stable Carbenes. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e100\u003c/strong\u003e, 39-92 (2000).\u003c/li\u003e\n\u003cli\u003eVignolle, J., Catto\u0026euml;n, X. \u0026amp; Bourissou, D. Stable noncyclic singlet carbenes. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e109\u003c/strong\u003e, 3333-3384 (2009).\u003c/li\u003e\n\u003cli\u003eSimons, R. S., Pu, L., Olmstead, M. M. \u0026amp; Power, P. P. Synthesis and characterization of the monomeric diaryls M{C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e-2,6-Mes\u003csub\u003e2\u003c/sub\u003e}\u003csub\u003e2\u003c/sub\u003e (M = Ge, Sn, or Pb; Mes = 2,4,6-Me\u003csub\u003e3\u003c/sub\u003eC\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e2\u003c/sub\u003e\u0026minus;) and dimeric aryl\u0026minus;metal chlorides [M(Cl){C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003e-2,6-Mes\u003csub\u003e2\u003c/sub\u003e}]\u003csub\u003e2\u003c/sub\u003e (M = Ge or Sn). \u003cem\u003eOrganometallics\u003c/em\u003e \u003cstrong\u003e16\u003c/strong\u003e, 1920-1925 (1997).\u003c/li\u003e\n\u003cli\u003eKato, T., Gornitzka, H., Baceiredo, A., Savin, A. \u0026amp; Bertrand, G. On the electronic structure of (phosphino)(silyl)carbenes:\u0026thinsp; single-crystal X-ray diffraction and ELF analyses. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e122\u003c/strong\u003e, 998-999 (2000).\u003c/li\u003e\n\u003cli\u003ePyykk\u0026ouml;, P. \u0026amp; Atsumi, M. Molecular double-bond covalent radii for elements Li\u0026ndash;E112. \u003cem\u003eChem. Eur. J.\u003c/em\u003e \u003cstrong\u003e15\u003c/strong\u003e, 12770-12779 (2009).\u003c/li\u003e\n\u003cli\u003eQueen, J. D., Irvankoski, S., Fettinger, J. C., Tuononen, H. M. \u0026amp; Power, P. P. A monomeric aluminum imide (iminoalane) with Al\u0026ndash;N triple-bonding: bonding analysis and dispersion energy stabilization. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e143\u003c/strong\u003e, 6351-6356 (2021).\u003c/li\u003e\n\u003cli\u003eKlein, J. E. M. N. \u0026amp; Knizia, G. cPCET versus HAT: A direct theoretical method for distinguishing X\u0026ndash;H bond-activation mechanisms. \u003cem\u003eAngew. Chem., Int. Ed.\u003c/em\u003e \u003cstrong\u003e57\u003c/strong\u003e, 11913-11917 (2018).\u003c/li\u003e\n\u003cli\u003eKnizia, G. Intrinsic Atomic Orbitals: An unbiased bridge between quantum theory and chemical concepts. \u003cem\u003eJ. Chem. Theory Comput.\u003c/em\u003e \u003cstrong\u003e9\u003c/strong\u003e, 4834-4843 (2013).\u003c/li\u003e\n\u003cli\u003eSavin, A., Nesper, R., Wengert, S. \u0026amp; F\u0026auml;ssler, T. F. ELF: the electron localization function. \u003cem\u003eAngew. Chem. Int. Ed. Engl.\u003c/em\u003e \u003cstrong\u003e36\u003c/strong\u003e, 1808-1832 (1997).\u003c/li\u003e\n\u003cli\u003eIgau, A., Baceiredo, A., Gruetzmacher, H., Pritzkow, H. \u0026amp; Bertrand, G. Synthesis, reactivity, and crystal structure of the first methylenephosphonium ion: a severely twisted valence isoelectronic olefin. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e111\u003c/strong\u003e, 6853-6854 (1989).\u003c/li\u003e\n\u003cli\u003eHu, C., Wang, X.-F., Li, J., Chang, X.-Y. \u0026amp; Liu, L. L. A stable rhodium-coordinated carbene with a \u0026sigma;\u003csup\u003e0\u003c/sup\u003e\u0026pi;\u003csup\u003e2\u003c/sup\u003e electronic configuration. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e383\u003c/strong\u003e, 81-85 (2024).\u003c/li\u003e\n\u003cli\u003eGr\u0026uuml;tzmacher, H., Freitag, S., Herbst-Irmer, R. \u0026amp; Sheldrick, G. S. Investigations of the structure and reactivity of a stannaketenimine. \u003cem\u003eAngew. Chem. Int. Ed. Engl.\u003c/em\u003e \u003cstrong\u003e31\u003c/strong\u003e, 437-438 (1992).\u003c/li\u003e\n\u003cli\u003eMansikkam\u0026auml;ki, A., Power, P. P. \u0026amp; Tuononen, H. M. Computational analysis of n\u0026rarr;\u0026pi;* back-bonding in metallylene\u0026ndash;isocyanide complexes R\u003csub\u003e2\u003c/sub\u003eMCNR\u0026prime; (M = Si, Ge, Sn; R = tBu, Ph; R\u0026prime; = Me, tBu, Ph). \u003cem\u003eOrganometallics\u003c/em\u003e \u003cstrong\u003e32\u003c/strong\u003e, 6690-6700 (2013).\u003c/li\u003e\n\u003cli\u003eMizuhata, Y., Sasamori, T. \u0026amp; Tokitoh, N. Stable heavier carbene analogues. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e109\u003c/strong\u003e, 3479-3511 (2009).\u003c/li\u003e\n\u003cli\u003eSetaka, W., Sakamoto, K., Kira, M. \u0026amp; Power, P. P. Synthesis and structure of stable tri-tert-butylgermyl-substituted stannylene and germylene. \u003cem\u003eOrganometallics\u003c/em\u003e \u003cstrong\u003e20\u003c/strong\u003e, 4460-4462 (2001).\u003c/li\u003e\n\u003cli\u003eProtchenko, A. V.\u003cem\u003e et al.\u003c/em\u003e Enabling and probing oxidative addition and reductive elimination at a group 14 metal center: cleavage and functionalization of E\u0026ndash;H bonds by a bis(boryl)stannylene. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e138\u003c/strong\u003e, 4555-4564 (2016).\u003c/li\u003e\n\u003cli\u003eEmig, N., Tejeda, J., R\u0026eacute;au, R. \u0026amp; Bertrand, G. The surprising instability of (phosphino)(stannyl)carbenes! \u003cem\u003eTetrahedron Lett.\u003c/em\u003e \u003cstrong\u003e36\u003c/strong\u003e, 4231-4234 (1995).\u003c/li\u003e\n\u003cli\u003eLi, Z.\u003cem\u003e et al.\u003c/em\u003e N-Heterocyclic carbenes as promotors for the rearrangement of phosphaketenes to phosphaheteroallenes: A case study for OCP to OPC constitutional isomerism. \u003cem\u003eAngew. Chem., Int. Ed.\u003c/em\u003e \u003cstrong\u003e55\u003c/strong\u003e, 6018-6022 (2016).\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eExperimental details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthetic methods.\u003c/strong\u003e All manipulations were conducted within a nitrogen-filled glovebox or under a dry nitrogen atmosphere, employing standard Schlenk techniques, unless otherwise specified. Toluene, \u003cem\u003en\u003c/em\u003e-hexane, \u003cem\u003en\u003c/em\u003e-pentane, and tetrahydrofuran were subjected to distillation over sodium or LiAlH\u003csub\u003e4\u0026nbsp;\u003c/sub\u003eand subsequently stored over activated molecular sieves in the glove box. Commercial reagents were obtained from Energy Chemical, J\u0026amp;K, or TCI Chemical Co. and were used without further purification. The reagents \u003cstrong\u003e1\u003c/strong\u003e\u003csup\u003e37\u003c/sup\u003e and 2,6-Mes\u003csub\u003e2\u003c/sub\u003eC\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003eSnCl\u003csup\u003e41\u003c/sup\u003e were prepared according to the reported literature.\u0026nbsp;Note: Although we have not experienced any problems, cautions should be exercised when handling diazo reagents due to their potentially explosive nature, especially for large scale reactions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSpectroscopic methods.\u0026nbsp;\u003c/strong\u003eNMR spectra were acquired at 298 K on a Bruker Avance 400 (\u003csup\u003e1\u003c/sup\u003eH: 400 MHz, \u003csup\u003e31\u003c/sup\u003eP: 162 MHz, \u003csup\u003e13\u003c/sup\u003eC: 101 MHz, \u003csup\u003e119\u003c/sup\u003eSn: 149 MHz) or 500 (\u003csup\u003e1\u003c/sup\u003eH: 500 MHz, \u003csup\u003e31\u003c/sup\u003eP: 202 MHz, \u003csup\u003e13\u003c/sup\u003eC: 126 MHz) or 600 (\u003csup\u003e1\u003c/sup\u003eH: 600 MHz, \u003csup\u003e31\u003c/sup\u003eP: 243 MHz, \u003csup\u003e13\u003c/sup\u003eC: 151 MHz) NMR spectrometer. The \u003csup\u003e1\u003c/sup\u003eH, \u003csup\u003e13\u003c/sup\u003eC{\u003csup\u003e1\u003c/sup\u003eH} spectra were referenced to residual internal C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003e, \u003csup\u003e31\u003c/sup\u003eP spectra was referenced externally to an 85% H\u003csub\u003e3\u003c/sub\u003ePO\u003csub\u003e4\u003c/sub\u003e solution in H\u003csub\u003e2\u003c/sub\u003eO, while \u003csup\u003e119\u003c/sup\u003eSn spectra was referenced with respect to SnMe\u003csub\u003e4\u003c/sub\u003e. The provided data is presented as follows: chemical shift, multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, sept = septet, m = multiplet and/or multiple resonances), coupling constant in hertz (Hz), integration and attribution). Deuterated solvent, such as C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e, THF-d\u003csub\u003e8\u003c/sub\u003e, CDCl\u003csub\u003e3,\u003c/sub\u003e were degassed by employing three freeze-pump-thaw cycles and stored over activated molecular sieves in the glove box.\u0026nbsp;High-resolution mass spectrometry (HRMS) was conducted using a Thermo Fisher Scientific Q-Exactive MS System. Infrared spectra were recorded on a FT-IR spectrometer (Bruker ALPHA II) using a DLaTGS detector. UV-Vis absorption spectra were recorded on Lambda 365 spectrophotometer (PerkinElmer) at room temperature. Elemental analyses (C, H, N) were conducted utilizing a Vario Micro Cube analyzer (Elementar, Germany).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCrystallographic methods.\u0026nbsp;\u003c/strong\u003eCrystal data was collected on a Bruker D8 VENTURE Diffractometer equipped with an Excillum METALJET diffractometer utilizing Ga-K\u0026alpha; (\u0026lambda; = 1.34139) radiation by APEX-Ⅲ\u0026nbsp;software suite.\u003csup\u003e57\u003c/sup\u003e SAINT was employed for integrating frames data. And the data was corrected for absorption effects using the empirical multi-scan method (SADABS).\u003csup\u003e58\u003c/sup\u003e The structures were solved using the SHELXT\u003csup\u003e59\u003c/sup\u003e structure solution program through the Intrinsic Phasing solution method and refined through Least Squares minimization method using SHELXL\u003csup\u003e60\u003c/sup\u003e\u003cem\u003e\u0026nbsp;\u003c/em\u003ein the graphical user interface Olex2.\u003csup\u003e61\u003c/sup\u003e Anisotropic refinement was applied to all non-hydrogen atoms, while structure factor calculations accounted for hydrogen atoms. The hydrogen atoms were positioned according to idealized geometric positions.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e A solution of \u003cem\u003e\u003csup\u003et\u003c/sup\u003e\u003c/em\u003eBuOK (21.5 mg, 0.19 mmol) in THF (3.0 mL) was gradually added to a THF solution of \u003cstrong\u003e1\u003c/strong\u003e (100 mg, 0.19 mmol) (3.0 mL) at a temperature of \u0026ndash;35℃. The resulting mixture was stirred for 10 minutes at \u0026ndash;35℃, followed by warming to room temperature and subsequent stirring for 7 hours. This reaction resulted in the complete consumption of \u003cstrong\u003e1\u003c/strong\u003e, yielding the formation of \u003cstrong\u003e1a\u003c/strong\u003e (\u003csup\u003e31\u003c/sup\u003eP NMR (THF): 131 ppm (s)). The solution was then cooled back to \u0026ndash;35℃, and a THF (3.0 mL) solution of\u0026nbsp;2,6-Mes\u003csub\u003e2\u003c/sub\u003eC\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u003c/sub\u003eSnCl\u0026nbsp;(89.4 mg, 0.19 mmol) was added slowly. After 10 minutes of stirring in the absence of light, all volatile components were removed under vacuum, resulting in the formation of a deep red oil. Pentane was introduced into the mixture, which was then filtered through a Celite pad, yielding a red solution. The remaining volatiles were subsequently removed under vacuum, and the resulting red powder was washed with cold pentane (3.0 mL), resulting in the isolation of \u003cstrong\u003e2\u003c/strong\u003e as a yellow solid (133 mg, 0.15 mmol) in a yield of 79%. Yellow crystals of \u003cstrong\u003e2\u003c/strong\u003e suitable for single-crystal X-ray diffraction were obtained by allowing a concentrated pentane solution to undergo slow evaporation at \u0026ndash;30℃.\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH NMR (500 MHz,\u0026nbsp;C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 1.01\u0026nbsp;(d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.8 Hz, 6H,\u0026nbsp;two sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eof Dipp), 1.21 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 7.1 Hz, 6H,\u0026nbsp;two sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eof Dipp), 1.30 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.9 Hz, 12H,\u0026nbsp;four sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eof Dipp), 1.97 (s, 12H,\u0026nbsp;four sets of\u0026nbsp;\u003cem\u003eo\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 2.21 (s, 6H,\u0026nbsp;two sets of\u0026nbsp;\u003cem\u003ep\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 3.11 (sept, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 7.1 Hz, 2H,\u0026nbsp;two sets of C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 3.55 \u0026ndash; 3.62 (m, 2H, NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 3.94 (sept, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.9 Hz, 2H,\u0026nbsp;two sets of C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 3.98 \u0026ndash; 4.09 (m, 2H, NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 6.55 (s, 4H, \u003cem\u003em\u003c/em\u003e-Mes), 6.86 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 7.5 Hz, 2H, \u003cem\u003em\u003c/em\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u0026nbsp;\u003c/sub\u003eof Ter), 7.08 \u0026ndash; 7.16 (m, 4H, Ar-\u003cem\u003eH\u003c/em\u003e), 7.25 (t, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 7.6 Hz, 3H, Ar-\u003cem\u003eH\u003c/em\u003e).\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC{\u003csup\u003e1\u003c/sup\u003eH} NMR (126 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 21.3, 21.5\u0026nbsp;(d, \u003csup\u003e4\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 4.0 Hz, \u003cem\u003eC\u003c/em\u003eH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e), 24.0, 24.2, 25.8, 26.1, 27.9, 29.0 (d, \u003csup\u003e4\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 9.1 Hz, \u003cem\u003eC\u003c/em\u003eH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e), 55.2 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u0026nbsp;\u003c/sub\u003e= 6.7 Hz, N\u003cem\u003eC\u003c/em\u003eH\u003csub\u003e2\u003c/sub\u003e), 124.6, 124.7, 127.5, 128.9, 129.0, 129.5, 136.4, 137.2, 139.4 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 13.9 Hz, P-N-\u003cem\u003eC\u003c/em\u003e\u003csub\u003eAr\u003c/sub\u003e), 146.9, 149.0, 150.1, 174.8 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 15.0 Hz, Sn-\u003cem\u003eo\u003c/em\u003e-\u003cem\u003eC\u003c/em\u003e\u003csub\u003eAr\u003c/sub\u003e). (Note: The signal corresponding to the quaternary carbon in close proximity to both Sn and P was not observed in the spectrum.). \u003csup\u003e31\u003c/sup\u003eP NMR (243 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 125.3 (s).\u0026nbsp;\u003csup\u003e119\u003c/sup\u003eSn NMR (149 MHz,\u0026nbsp;C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm)\u0026nbsp;92.7 (s).\u0026nbsp;HRMS [M-N\u003csub\u003e2\u003c/sub\u003e+H]\u003csup\u003e+\u003c/sup\u003e C\u003csub\u003e51\u003c/sub\u003eH\u003csub\u003e64\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003ePSn\u003csup\u003e+\u003c/sup\u003e calc. 855.38236 m/z, found 855.38195 m/z.\u0026nbsp;IR (ATR, neat): v = 2901, 1966 (N=N stretching), 1440, 1103, 961, 519 cm\u003csup\u003e\u0026ndash;\u003c/sup\u003e\u003csup\u003e1\u003c/sup\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e3.\u003c/strong\u003e A sample of compound \u003cstrong\u003e2\u003c/strong\u003e (234 mg, 0.265 mmol) was sealed in thick-walled pressure bottle. Subsequently, the solid was exposed to 303 nm light for a duration of 30 minutes at room temperature, resulting in the clean formation of compound \u003cstrong\u003e3\u003c/strong\u003e. Afterward, the resulting brown powder was washed with 2 mL of cold pentane. This procedure yielded compound \u003cstrong\u003e3\u003c/strong\u003e as a yellow solid (217 mg, 0.254 mmol, 96% yield). To obtain suitable single-crystal samples for X-ray diffraction analysis, yellow crystals of compound \u003cstrong\u003e3\u003c/strong\u003e were grown by gradually evaporating a concentrated pentane solution at a temperature of\u0026nbsp;\u0026ndash;30 \u0026deg;C over a duration of 48 hours.\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH NMR (600 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 1.20\u0026nbsp;(d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.9 Hz, 12H,\u0026nbsp;four sets of\u0026nbsp;CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003eof Dipp), 1.23 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.8 Hz, 12H,\u0026nbsp;four sets of\u0026nbsp;CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003eof Dipp), 2.13 (s,12H,\u0026nbsp;four sets of\u003cem\u003e\u0026nbsp;o\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 2.26 (s, 6H,\u0026nbsp;two sets of\u003cem\u003e\u0026nbsp;p\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 3.26 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.2 Hz, 4H, two sets of NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 3.45 (sept, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.9 Hz, 4H, four\u0026nbsp;sets of\u0026nbsp;C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e\u003csub\u003e\u0026nbsp;\u003c/sub\u003eof Dipp), 6.56 (s, 4H, \u003cem\u003em\u003c/em\u003e-Mes), 6.98 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 7.5 Hz, 2H, \u003cem\u003em\u003c/em\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u0026nbsp;\u003c/sub\u003eof Ter), 7.11 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 7.5 Hz, 4H, Ar-\u003cem\u003eH\u003c/em\u003e), 7.24 (q, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 8.0 Hz, 3H, Ar-\u003cem\u003eH\u003c/em\u003e).\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC {\u003csup\u003e1\u003c/sup\u003eH} NMR (151 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm)\u0026nbsp;21.5, 21.8, 24.7, 25.0, 29.2, 47.8 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u0026nbsp;\u003c/sub\u003e= 8.1 Hz, N\u003cem\u003eC\u003c/em\u003eH\u003csub\u003e2\u003c/sub\u003e), 124.5, 127.5, 127.6, 128.3, 128.5, 128.6, 130.5 (d, \u003csup\u003e1\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 50.1 Hz, P\u003cem\u003eC\u003c/em\u003eSn), 134.9 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 3.8 Hz, P-N-\u003cem\u003eC\u003c/em\u003e\u003csub\u003eAr\u003c/sub\u003e), 135.7, 136.6, 138.3, 146.5, 148.6, 179.5 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 35.4 Hz, Sn-\u003cem\u003eo\u003c/em\u003e-\u003cem\u003eC\u003c/em\u003e\u003csub\u003eAr\u003c/sub\u003e).\u0026nbsp;\u003csup\u003e31\u003c/sup\u003eP NMR (243 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 67.9 (singlet with two satellites, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eSn-P\u0026nbsp;\u003c/sub\u003e= 168.7 Hz).\u0026nbsp;\u003csup\u003e119\u003c/sup\u003eSn NMR (149 MHz,\u0026nbsp;C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e):\u0026nbsp;\u0026delta; 1149.3 (d,\u0026nbsp;\u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eSn-P\u0026nbsp;\u003c/sub\u003e= 168.7 Hz).\u0026nbsp;HRMS [M+H]\u003csup\u003e+\u003c/sup\u003e C\u003csub\u003e51\u003c/sub\u003eH\u003csub\u003e64\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003ePSn\u003csup\u003e+\u003c/sup\u003e calc. 855.38236 m/z, found 855.38196 m/z.\u0026nbsp;IR (ATR, neat): v = 2952, 1364, 1178, 909, 755, 537 cm\u003csup\u003e\u0026ndash;\u003c/sup\u003e\u003csup\u003e1\u003c/sup\u003e. Anal. Calcd for\u0026nbsp;C\u003csub\u003e51\u003c/sub\u003eH\u003csub\u003e63\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003ePSn: C, 71.75; H, 7.44; N, 3.28; Found: C, 70.62; H, 7.41; N, 3.35.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e4\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e A solution of 1-adamantyl isocyanide (AdNC) (6 mg, 0.374 mmol) in tetrahydrofuran (THF) (2.0 mL) was slowly introduced into another THF solution containing \u003cstrong\u003e3\u003c/strong\u003e (32 mg, 0.374 mmol) (2.0 mL) at room temperature. The resulting mixture was stirred at room temperature for 20 minutes, followed by the removal of volatiles under vacuum. The resulting yellow powder was subsequently washed with 1.0 mL of cold hexane, resulting in the formation of yellow solid \u003cstrong\u003e4\u003c/strong\u003e (25 mg, 0.0246 mmol) with a yield of 66%. To obtain yellow crystals suitable for single-crystal X-ray diffraction analysis, a concentrated hexane solution of compound \u003cstrong\u003e4\u003c/strong\u003e was subjected to slow evaporation at\u0026nbsp;\u0026ndash;30\u0026deg;C.\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH NMR (600 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 0.98\u0026nbsp;(d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.7 Hz, 6H, two sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp),\u0026nbsp;1.26 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.8 Hz, 6H, two sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.31 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.9 Hz, 6H, two sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.35 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.9 Hz, 6H, two sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.39 \u0026ndash; 1.44 (m, 2H, Ad-\u003cem\u003eH\u003c/em\u003e), 1.46 (s, 6H, Ad-\u003cem\u003eH\u003c/em\u003e), 1.48 (s, 1H, Ad-\u003cem\u003eH\u003c/em\u003e), 1.54 \u0026ndash; 1.57 (m, 1H, Ad-\u003cem\u003eH\u003c/em\u003e), 1.66 (s, 1H, Ad-\u003cem\u003eH\u003c/em\u003e), 1.87 (s, 4H, Ad-\u003cem\u003eH\u003c/em\u003e overlapped with \u003cem\u003eo\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 1.89 (s, 9 H, three sets of \u003cem\u003eo\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e), 2.24 (s, 9H, Ad-\u003cem\u003eH\u003c/em\u003e overlapped with \u003cem\u003ep\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 3.14 \u0026ndash; 3.23 (m, 2H, NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 3.76 (sept, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.9 Hz, 2H, two\u0026nbsp;sets of C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e), 3.86 (sept, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.9 Hz, 2H, two\u0026nbsp;sets of C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e), 3.92 \u0026ndash; 4.07 (m, 2 H, NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 6.55 (s, 4H, \u003cem\u003em\u003c/em\u003e-Mes), 6.87 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 7.4 Hz, 2H, \u003cem\u003em\u003c/em\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u0026nbsp;\u003c/sub\u003eof Ter), 7.14 (s, 1H, Ar-\u003cem\u003eH\u003c/em\u003e), 7.20 \u0026ndash; 7.26 (m, 4H, Ar-\u003cem\u003eH\u003c/em\u003e), 7.31 (t, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 7.6 Hz, 2H, Ar-\u003cem\u003eH\u003c/em\u003e).\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC {\u003csup\u003e1\u003c/sup\u003eH} NMR (151 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm)\u0026nbsp;21.3, 21.4, 23.6, 25.1, 26.1, 26.8, 27.7, 28.8 (d, \u003csup\u003e4\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 6.5 Hz, \u003cem\u003eC\u003c/em\u003eH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e), 30.1, 36.2, 44.7, 55.3 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u0026nbsp;\u003c/sub\u003e= 7.3 Hz, N\u003cem\u003eC\u003c/em\u003eH\u003csub\u003e2\u003c/sub\u003e), 57.5, 102.3 (d, \u003csup\u003eJ\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u0026nbsp;\u003c/sub\u003e= 156.1 Hz, P\u003cem\u003eC\u003c/em\u003eSn), 124.8 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u0026nbsp;\u003c/sub\u003e= 59.9 Hz, C\u003cem\u003eC\u003c/em\u003eN), 127.1, 128.8, 136.7, 136.9, 141.0 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 14.2 Hz, P-N-\u003cem\u003eC\u003c/em\u003e\u003csub\u003eAr\u003c/sub\u003e), 146.9, 149.4, 150.1, 161.9, 177.0 (Sn-\u003cem\u003eo\u003c/em\u003e-\u003cem\u003eC\u003c/em\u003e\u003csub\u003eAr\u003c/sub\u003e).\u0026nbsp;\u003csup\u003e31\u003c/sup\u003eP NMR (243 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 112.2 (s).\u0026nbsp;\u003csup\u003e119\u003c/sup\u003eSn NMR (149 MHz,\u0026nbsp;C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm)1486.8\u0026nbsp;(s).\u0026nbsp;HRMS [M+H]\u003csup\u003e+\u003c/sup\u003e C\u003csub\u003e62\u003c/sub\u003eH\u003csub\u003e79\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003ePSn\u003csup\u003e+\u003c/sup\u003e calc. 1016.50281 m/z, found 1016.50629 m/z.\u003c/p\u003e\n\u003cp\u003eIR (ATR, neat): v =2908, 1967\u0026nbsp;(CCN stretching), 1441, 1056, 804, 766 cm\u003csup\u003e\u0026ndash;\u003c/sup\u003e\u003csup\u003e1\u003c/sup\u003e. Anal. Calcd for\u0026nbsp;C\u003csub\u003e62\u003c/sub\u003eH\u003csub\u003e78\u003c/sub\u003eN\u003csub\u003e3\u003c/sub\u003ePSn: C, 73.37; H, 7.75; N, 4.14; Found: C, 72.97; H, 7.83; N, 4.21.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e5\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eAn excess of 2,3-dimethyl-1,3-butadiene was introduced into a solution of compound \u003cstrong\u003e3\u003c/strong\u003e (31 mg, 0.0364 mmol) in THF\u0026nbsp;(1.0 mL). The resulting mixture was stirred for 16 hours at room temperature. Subsequently, all volatiles were removed under vacuum, resulting in the formation of a brown oil. The brown oil was dissolved in 0.5 mL of hexane and stored at -35\u0026deg;C in a freezer for a duration of one week, leading to the formation of colorless crystals of product \u003cstrong\u003e5\u003c/strong\u003e (22 mg, 0.0235 mmol) with a yield of 65%.\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH NMR (600 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 0.34\u0026nbsp;(d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 15.7 Hz, 2H, SnC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e),\u0026nbsp;0.81\u0026nbsp;(d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 15.5 Hz, 2H, SnC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 1.24 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 5.4 Hz, 12H,\u0026nbsp;four sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.30 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 5.4 Hz, 12H,\u0026nbsp;four sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.62 (s, 6H, two\u0026nbsp;sets of\u0026nbsp;C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of SnCH\u003csub\u003e2\u003c/sub\u003eCCH\u003csub\u003e3\u003c/sub\u003e), 2.04 (s,12H, four sets of \u003cem\u003eo\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 2.31 (s, 6H, four sets of \u003cem\u003ep\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 3.23 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 5.4 Hz, 4H, four\u0026nbsp;sets of C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e), 3.40 \u0026ndash; 3.51 (m, 4H, two sets of NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 6.83 (s, 4H, \u003cem\u003em\u003c/em\u003e-Mes), 6.87 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 7.6 Hz, 2H, \u003cem\u003em\u003c/em\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u0026nbsp;\u003c/sub\u003eof Ter), 7.08 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 7.4 Hz, 4H, Ar-\u003cem\u003eH\u003c/em\u003e), 7.16 \u0026ndash; 7.20 (m, 3H, Ar-\u003cem\u003eH\u003c/em\u003e).\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC{\u003csup\u003e1\u003c/sup\u003eH} NMR (151 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm)\u0026nbsp;21.4, 21.4, 21.6, 24.7, 25.0, 27.3, 29.3, 47.7 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e= 6.1 Hz, N\u003cem\u003eC\u003c/em\u003eH\u003csub\u003e2\u003c/sub\u003e), 124.4, 127.6, 128.4, 128.6, 128.6, 129.1, 130.9, 130.9 (d, \u003csup\u003e1\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 34.0 Hz, P\u003cem\u003eC\u003c/em\u003eSn), 135.5, 135.6, 136.7, 142.0, 148.7, 150.0.\u0026nbsp;\u003csup\u003e31\u003c/sup\u003eP NMR (243 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 3.7 (singlet with two satellites, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eSn-P\u0026nbsp;\u003c/sub\u003e=181.4 Hz).\u0026nbsp;\u003csup\u003e119\u003c/sup\u003eSn NMR (149 MHz,\u0026nbsp;C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) \u0026ndash;43.6 (d,\u0026nbsp;\u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eSn-P\u0026nbsp;\u003c/sub\u003e=181.4 Hz).\u0026nbsp;HRMS [M+H]\u003csup\u003e+\u003c/sup\u003e C\u003csub\u003e57\u003c/sub\u003eH\u003csub\u003e74\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003ePSn\u003csup\u003e+\u003c/sup\u003e calc. 937.46061 m/z, found 937.46191 m/z.\u0026nbsp;IR (ATR, neat): v = 2960, 1442, 1256, 1074, 847, 802 cm\u003csup\u003e\u0026ndash;\u003c/sup\u003e\u003csup\u003e1\u003c/sup\u003e. Anal. Calcd for\u0026nbsp;C\u003csub\u003e57\u003c/sub\u003eH\u003csub\u003e73\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003ePSn: C, 73.15; H, 7.86; N, 2.99; Found: C, 71.29; H, 7.86; N, 3.09.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e6\u003c/strong\u003e\u003cstrong\u003e.\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eInside the glovebox, a pre-cooled solution of THF (3 mL) was added dropwise to a mixture comprising compound \u003cstrong\u003e3\u003c/strong\u003e (38.6 mg, 0.0452 mmol) and Et\u003csub\u003e3\u003c/sub\u003eN\u0026middot;HCl (12.4 mg, 0.0904 mmol). Following stirring at\u0026nbsp;\u0026ndash;35\u0026deg;C for 15 minutes, the resulting mixture was filtered through a Celite pad, resulting in the formation of a white solution. Subsequently, all volatiles were removed under vacuum. The resulting white powder was then washed with 3.0 mL of cold hexane, affording white solid \u003cstrong\u003e6\u003c/strong\u003e (28.5 mg, 0.307 mmol) with a yield of 68%. To obtain colorless crystals suitable for single-crystal X-ray diffraction analysis, a concentrated hexane solution of compound \u003cstrong\u003e6\u003c/strong\u003e was subjected to slow evaporation at\u0026nbsp;\u0026ndash;30\u0026deg;C.\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH NMR (600 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm)\u0026nbsp;1.21 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.6 Hz, 6H, two sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.28 (m, 12H,\u0026nbsp;four\u0026nbsp;sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.41 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.6 Hz, 6H,\u0026nbsp;two\u0026nbsp;sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.64 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 5.0 Hz, 2H, PC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 2.00 (s, 12H, four sets of \u003cem\u003eo\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 2.18 (s, 6H, two sets of\u003cem\u003e\u0026nbsp;p\u003c/em\u003e-C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 3.08 \u0026ndash; 3.20 (m, 2H, NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 3.26 \u0026ndash; 3.38 (m, 2H,\u0026nbsp;two sets of\u0026nbsp;C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eof Dipp), 3.61 (sept, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.6 Hz, 2H, two\u0026nbsp;sets of\u0026nbsp;C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eof Dipp), 3.72 (m, 2H, NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 6.66 (s, 4H, \u003cem\u003em\u003c/em\u003e-Mes), 6.78 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 7.5 Hz, 2H, \u003cem\u003em\u003c/em\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u0026nbsp;\u003c/sub\u003eof Ter), 7.08 (t, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 7.5 Hz, 1H, \u003cem\u003ep\u003c/em\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u0026nbsp;\u003c/sub\u003eof Ter), 7.15 (s, 2H, Ar-\u003cem\u003eH\u003c/em\u003e), 7.17 (s, 2H, Ar-\u003cem\u003eH\u003c/em\u003e), 7.19 \u0026ndash; 7.23 (m, 2H, Ar-\u003cem\u003eH\u003c/em\u003e).\u0026nbsp;\u003csup\u003e13\u003c/sup\u003eC{\u003csup\u003e1\u003c/sup\u003eH} NMR (151 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm)\u0026nbsp;21.3, 21.6 (d, \u003csup\u003e4\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 3.0 Hz, \u003cem\u003eC\u003c/em\u003eH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e), 24.0, 24.8, 26.5, 29.0, 29.2 (d, \u003csup\u003e4\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 11.9 Hz, \u003cem\u003eC\u003c/em\u003eH(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e), 36.2 (d, \u003csup\u003e1\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 89.2 Hz, P\u003cem\u003eC\u003c/em\u003eH\u003csub\u003e2\u003c/sub\u003e), 55.1 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u0026nbsp;\u003c/sub\u003e= 6.1 Hz, N\u003cem\u003eC\u003c/em\u003eH\u003csub\u003e2\u003c/sub\u003e), 124.5, 124.8, 127.0, 128.3, 129.1, 129.6, 131.9, 136.8, 138.0, 138.2, 140.2 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 12.5 Hz, P-N-\u003cem\u003eC\u003c/em\u003e\u003csub\u003eAr\u003c/sub\u003e), 141.6, 148.0, 149.0, 149.4.\u0026nbsp;\u003csup\u003e31\u003c/sup\u003eP NMR (243 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 111.3 (singlet with two satellites, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eSn-P\u0026nbsp;\u003c/sub\u003e= 263.1 Hz).\u0026nbsp;\u003csup\u003e119\u003c/sup\u003eSn NMR (149 MHz,\u0026nbsp;C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm)\u0026nbsp;\u0026ndash;13.2 (d,\u0026nbsp;\u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eSn-P\u0026nbsp;\u003c/sub\u003e= 263.1 Hz).\u0026nbsp;HRMS [M]\u003csup\u003e+\u003c/sup\u003e C\u003csub\u003e51\u003c/sub\u003eH\u003csub\u003e65\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003eCl\u003csub\u003e2\u003c/sub\u003ePSn\u003csup\u003e+\u003c/sup\u003e calc. 926.32789 m/z, found 926.32904 m/z.\u0026nbsp;HRMS [M]\u003csup\u003e+\u003c/sup\u003e C\u003csub\u003e51\u003c/sub\u003eH\u003csub\u003e65\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003eCl\u003csup\u003e37\u003c/sup\u003eClPSn\u003csup\u003e+\u003c/sup\u003e calc. 928.32494 m/z, found 928.33063 m/z.\u0026nbsp;IR (ATR, neat): v = 2963, 1443, 1070, 850, 804, 757 cm\u003csup\u003e\u0026ndash;\u003c/sup\u003e\u003csup\u003e1\u003c/sup\u003e.\u0026nbsp;Anal. Calcd for\u0026nbsp;C\u003csub\u003e51\u003c/sub\u003eH\u003csub\u003e65\u003c/sub\u003eCl\u003csub\u003e2\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003ePSn: C, 66.10; H, 7.07; N, 3.02; Found: C, 63.11; H, 7.00; N, 2.93.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSynthesis of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e7.\u003c/strong\u003e A solution of isopropyl isocyanate (\u003cem\u003e\u003csup\u003ei\u003c/sup\u003e\u003c/em\u003ePrNCO) (10 mg, 0.12 mmol) in THF (2.0 mL) was slowly introduced into another THF solution containing \u003cstrong\u003e3\u003c/strong\u003e (50 mg, 0.059 mmol) (2.0 mL) at\u0026nbsp;\u0026ndash;35\u0026deg;C. The resulting mixture was stirred at room temperature for 10 minutes, followed by the removal of volatiles under vacuum. The resulting white powder was subsequently washed with 1.0 mL of cold pentane, resulting in the formation of white solid \u003cstrong\u003e7\u003c/strong\u003e (32 mg, 0.031 mmol) with a yield of 54%. To obtain colorless crystals suitable for single-crystal X-ray diffraction analysis, a concentrated pentane and toluene solution of compound \u003cstrong\u003e7\u003c/strong\u003e was subjected to slow evaporation at\u0026nbsp;\u0026ndash;30\u0026deg;C.\u0026nbsp;\u003csup\u003e1\u003c/sup\u003eH NMR (500 MHz,\u0026nbsp;C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 0.16\u0026nbsp;(t, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 7.5 Hz, 6H, two sets of NCH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e), 0.54 (s, 3H, NC(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003eN), 0.70 (s, 3H, NC(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003eN), 1.04 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.7 Hz, 3H, CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.16 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.7 Hz, 3H, CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.26 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.9 Hz, 3H, CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.40 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.6 Hz, 6H, two sets of CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.45 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.9 Hz, 3H, CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.68 (d, \u003cem\u003eJ\u003c/em\u003e = 6.7 Hz, 3H, CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 1.72 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.6 Hz, 3H, CH(C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e of Dipp), 2.06 (s, 3H, C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 2.20 (s, 3H, C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes),\u0026nbsp;2.30\u0026nbsp;(s, 3H, C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes),\u0026nbsp;2.34\u0026nbsp;(s, 3H, C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes),\u0026nbsp;2.40\u0026nbsp;(t, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 7.5 Hz, 1H, NC\u003cem\u003eH\u003c/em\u003eMe\u003csub\u003e2\u003c/sub\u003e),\u0026nbsp;2.49\u0026nbsp;(s, 3H, C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes),\u0026nbsp;2.55 (s, 3H,\u0026nbsp;C\u003cem\u003eH\u003c/em\u003e\u003csub\u003e3\u003c/sub\u003e of Ter-Mes), 3.25 \u0026ndash; 3.39 (m, 1H,\u0026nbsp;NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 3.64 (sept, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e= 6.7 Hz, 1H, C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eof Dipp), 3.68 \u0026ndash; 3.75 (m, 1H,\u0026nbsp;NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 3.77 \u0026ndash; 3.86 (m, 1H,\u0026nbsp;NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 4.01 (sept, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e= 6.9 Hz, 1H, C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eof Dipp), 4.22 \u0026ndash; 4.31 (m, 1H,\u0026nbsp;NC\u003cem\u003eH\u003c/em\u003e\u003csub\u003e2\u003c/sub\u003e), 4.35 (sept, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.7 Hz, 1H, C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eof Dipp), 4.43 (sept, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u0026nbsp;\u003c/sub\u003e= 6.6 Hz, 1H, C\u003cem\u003eH\u003c/em\u003e(CH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eof Dipp), 6.77 \u0026ndash; 6.90 (m, 4H,\u0026nbsp;Ar-\u003cem\u003eH\u003c/em\u003e), 6.94 \u0026ndash; 7.03 (m, 1H,\u0026nbsp;Ar-\u003cem\u003eH\u003c/em\u003e), 7.16 \u0026ndash; 7.21 (m, 3H,\u0026nbsp;Ar-\u003cem\u003eH\u003c/em\u003e), 7.20 \u0026ndash; 7.26 (m, 4H,\u0026nbsp;Ar-\u003cem\u003eH\u003c/em\u003e), 7.30 (t, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eH-H\u003c/sub\u003e = 7.7 Hz, 1H, \u003cem\u003ep\u003c/em\u003e-C\u003csub\u003e6\u003c/sub\u003eH\u003csub\u003e3\u0026nbsp;\u003c/sub\u003eof Ter), 7.41 (d,\u0026nbsp;\u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-H\u003c/sub\u003e = 12.0 Hz, 1H, PCC\u003cem\u003eH\u003c/em\u003e). \u003csup\u003e13\u003c/sup\u003eC{\u003csup\u003e1\u003c/sup\u003eH} NMR (126 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e):\u0026nbsp;\u0026delta;\u0026nbsp;(ppm)\u0026nbsp;21.0, 21.4, 21.8, 21.9, 22.5, 22.6, 22.9, 23.1, 25.0, 25.3, 25.5, 25.9, 26.0, 26.2, 26.6, 27.1, 27.4, 27.6, 28.8, 29.2, 29.4, 47.7 (N\u003cem\u003eC\u003c/em\u003eH), 48.8 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 13.6 Hz, N\u003cem\u003eC\u003c/em\u003eH\u003csub\u003e2\u003c/sub\u003e), 50.5 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 13.4 Hz, N\u003cem\u003eC\u003c/em\u003eH\u003csub\u003e2\u003c/sub\u003e), 75.8 (N\u003cem\u003eC\u003c/em\u003eN), 90.3 (d, \u003csup\u003e1\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 192.1 Hz, P-\u003cem\u003eC\u003c/em\u003e), 124.2, 125.2, 125.4, 128.8 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 12.0 Hz, P-N-\u003cem\u003eC\u003c/em\u003e, Ar-\u003cem\u003eC\u003c/em\u003e), 129.2, 129.9, 135.4, 135.5, 136.1, 136.8, 137.0, 138.0, 139.6, 142.7, 146.2, 148.2, 150.7, 150.9 (d, \u003csup\u003e3\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 3.3 Hz, P-N-C-\u003cem\u003eC\u003c/em\u003e, Ar-\u003cem\u003eC\u003c/em\u003e), 151.0, 151.2, 154.7 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 16.2 Hz, PC\u003cem\u003eC\u003c/em\u003eH), 169.0 (d, \u003csup\u003e2\u003c/sup\u003e\u003cem\u003eJ\u003c/em\u003e\u003csub\u003eP-C\u003c/sub\u003e = 6.1 Hz, O-\u003cem\u003eC\u003c/em\u003e-N), 174.3 (Sn-\u003cem\u003eo\u003c/em\u003e-\u003cem\u003eC\u003c/em\u003e\u003csub\u003eAr\u003c/sub\u003e).\u0026nbsp;\u003csup\u003e31\u003c/sup\u003eP NMR (243 MHz, C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e): \u0026delta; (ppm) 15.7.\u0026nbsp;\u003csup\u003e119\u003c/sup\u003eSn NMR (149 MHz,\u0026nbsp;C\u003csub\u003e6\u003c/sub\u003eD\u003csub\u003e6\u003c/sub\u003e):\u0026nbsp;\u0026delta;\u0026nbsp;(ppm) 342.9.\u0026nbsp;HRMS [M+H]\u003csup\u003e+\u003c/sup\u003e C\u003csub\u003e59\u003c/sub\u003eH\u003csub\u003e78\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003ePSn\u003csup\u003e+\u003c/sup\u003e calc. 1025.48789 m/z, found 1025.49072 m/z.\u0026nbsp;IR (ATR, neat): v = 2946, 1587, 1442, 1292, 1094, 805 cm\u003csup\u003e\u0026ndash;\u003c/sup\u003e\u003csup\u003e1\u003c/sup\u003e.\u0026nbsp;Anal. Calcd for\u0026nbsp;C\u003csub\u003e59\u003c/sub\u003eH\u003csub\u003e77\u003c/sub\u003eN\u003csub\u003e4\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003ePSn: C, 69.21; H, 7.58; N, 5.47; Found: C, 66.72; H, 7.64; N, 5.77.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComputational details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGeometry optimizations were carried out using the Gaussian 16 package\u003csup\u003e62\u003c/sup\u003e with the BP86 functional\u003csup\u003e63,64\u003c/sup\u003e augmented with the D3BJ version of Grimme\u0026rsquo;s empirical dispersion correction.\u003csup\u003e65,66,67\u003c/sup\u003e The def2-TZVPP basis set was used for all the atoms. Frequency calculations at the same level of theory were performed to identify the number of imaginary frequencies (zero for local minimum). Natural bond orbital (NBO) calculations\u0026nbsp;and natural resonance theory (NRT) calculations\u0026nbsp;were carried out using NBO 7.0 program\u003csup\u003e68\u003c/sup\u003e at the BP86-D3(BJ)/def2-TZVPP level of theory, intrinsic bond orbitals (IBOs) were carried out using ORCA program\u003csup\u003e69\u003c/sup\u003e at the same level. Optimized structures were visualized by the Chemcraft\u003csup\u003e70\u003c/sup\u003e or IBOview program.\u003csup\u003e46\u0026nbsp;\u003c/sup\u003eThe electron localization function (ELF) analysis\u003csup\u003e47\u003c/sup\u003e were carried out using Amsterdam Modeling Suite\u003csup\u003e71\u003c/sup\u003e at the BP86-D3(BJ)/TZP level of theory using the BP86-D3(BJ)/def2-TZVPP optimized geometries, the relativistic scalar effect was included by using the zeroth-order regular approximation (ZORA).\u003csup\u003e72,73\u0026nbsp;\u003c/sup\u003eTD-DFT calculations were carried out at the M062X/def2-TZVP level of theory.\u0026nbsp;Isotropic shifts for \u003cstrong\u003eInt2A\u003c/strong\u003e were computed at the GIAO-B97-2\u003csup\u003e74\u003c/sup\u003e/Def2-TZVP\u003csup\u003e75,76\u003c/sup\u003e//BP86-D3(BJ)/def2-SVP\u0026nbsp;level of theory.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCrystallographic data for the structures reported in this Article have been deposited at the Cambridge Crystallographic Data Centre, under deposition numbers\u0026nbsp;2261177 (\u003cstrong\u003e2\u003c/strong\u003e), 2261179 (\u003cstrong\u003e3\u003c/strong\u003e), 2261180 (\u003cstrong\u003e4\u003c/strong\u003e), 2261178 (\u003cstrong\u003e5\u003c/strong\u003e), 2261181 (\u003cstrong\u003e6\u003c/strong\u003e) and 2261213 (\u003cstrong\u003e7\u003c/strong\u003e). Copies of the data can be obtained free of charge via https://www.ccdc.cam.ac.uk/structures/.\u0026nbsp;All other data are presented in the main text and the Supplementary Information, and are also available from the corresponding authors on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods-only references\u003c/strong\u003e\u003c/p\u003e\n\u003col start=\"57\"\u003e\n \u003cli\u003eAPEX suite of crystallographic software (APEX 3 version 2015.5-2 \u0026amp; Bruker AXS Inc.: Madison, Wisconsin, USA. 2015).\u003c/li\u003e\n \u003cli\u003eBruker AXS Inc., in Bruker Apex CCD, SAINT v8.40B, WI, USA, Madison, 2019.\u003c/li\u003e\n \u003cli\u003eSheldrick, G. M. SHELXT-Integrated space-group and crystal-structure determination. \u003cem\u003eActa Cryst. A\u003c/em\u003e, \u003cstrong\u003eA71\u003c/strong\u003e, 3-8 (2015).\u003c/li\u003e\n \u003cli\u003eSheldrick, G. M. Crystal structure refinement with SHELXL. \u003cem\u003eActa Cryst.\u003c/em\u003e \u003cstrong\u003eC71\u003c/strong\u003e, 3\u0026ndash;8 (2015).\u003c/li\u003e\n \u003cli\u003eDolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K., Puschmann, H. OLEX2: a complete structure solution, refinement and analysis program. \u003cem\u003eJ. Appl. Cryst.\u003c/em\u003e \u003cstrong\u003e42\u003c/strong\u003e, 339- 341 (2009).\u003c/li\u003e\n \u003cli\u003eFrisch, M. J. et al. Gaussin 16 rev. B.01 (Gaussian, Inc., Wallingford CT, 2016).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eLee, C., Yang, W. \u0026amp; Parr, R. G. Development of the colle-salvetti correlation-energy formula into a functional of the electron density. \u003cem\u003ePhys. Rev. B\u003c/em\u003e \u003cstrong\u003e37\u003c/strong\u003e, 785-789 (1988).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eStephens, P. J., Devlin, F. J., Chabalowski, C. F. \u0026amp; Frisch, M. J. Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields. \u003cem\u003eJ. Phys. Chem.\u003c/em\u003e \u003cstrong\u003e98\u003c/strong\u003e, 11623-11627 (1994).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eGrimme, S., Antony, J., Ehrlich, S. \u0026amp; Krieg, H. A consistent and accurate ab initio parametrization of density functional dispersion correction (DFT-D) for the 94 elements H-Pu. \u003cem\u003eJ. Chem. Phys\u003c/em\u003e. \u003cstrong\u003e132\u003c/strong\u003e, 154104-154133 (2010).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eGrimme, S. Semiempirical GGA-type density functional constructed with a long-range dispersion correction, \u003cem\u003eJ. Comput. Chem.\u003c/em\u003e \u003cstrong\u003e27\u003c/strong\u003e, 1787-1799 (2006).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eGrimme, S. Accurate description of van der waals complexes by density functional theory including empirical corrections.\u003cem\u003e\u0026nbsp;J. Comput. Chem\u003c/em\u003e. \u003cstrong\u003e25\u003c/strong\u003e, 1463-1473 (2004).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eGlendening, E. D., Badenhoop, J. K., Reed, A. E., Carpenter, J. E., Bohmann, J. A., Morales, C. M., Karafiloglou P., Landis C. R. \u0026amp; Weinhold, F., NBO 7.0, University of Wisconsin: Madison, WI, 2018.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eNeese, F. The ORCA program system. \u003cem\u003eWIREs Comput. Mol. Sci.\u003c/em\u003e \u003cstrong\u003e2\u003c/strong\u003e, 73-78 (2012).\u003c/li\u003e\n \u003cli\u003eAndrienko, G. A. ChemCraft, http://www.chemcraftprog.com.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eVan Gisbergen, S., Snijders, J. \u0026amp; Ziegler, T. Chemistry with ADF. \u003cem\u003eJ. Comput. Chem\u003c/em\u003e \u003cstrong\u003e22\u003c/strong\u003e, 931-967 (2001).\u003c/li\u003e\n \u003cli\u003eChang, C., Pelissier, M. \u0026amp; Durand, P. Regular two-component pauli-like effective hamiltonians in dirac theory. \u003cem\u003ePhys. Scr\u003c/em\u003e. \u003cstrong\u003e34\u003c/strong\u003e, 394-404 (1986).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eHeully, J. L., Lindgren, I., Lindroth, E., Lundqvist, S. \u0026amp; Martensson-Pendrill, A. M. Diagonalisation of the dirac hamiltonian as a basis for a relativistic many-body procedure.\u003cem\u003e\u0026nbsp;J. Phys. B\u003c/em\u003e \u003cstrong\u003e19\u003c/strong\u003e, 2799-2815 (1986).\u003c/li\u003e\n \u003cli\u003eWilson, P. J., Bradley, T. J. \u0026amp; Tozer, D. J. Hybrid exchange-correlation functional determined from thermochemical data and ab initio potentials, \u003cem\u003eJ. Chem. Phys.\u003c/em\u003e \u003cstrong\u003e115\u003c/strong\u003e, 9233-9242 (2001).\u003c/li\u003e\n \u003cli\u003eWeigend, F., Ahlrichs, R. Balanced basis sets of split valence, triple zeta vlence and quadruple zeta valence quality for H to Rn: design and assessment of accuracy, \u003cem\u003ePhys.\u003c/em\u003e \u003cem\u003eChem. Chem. Phys.\u003c/em\u003e \u003cstrong\u003e7\u003c/strong\u003e, 3297-3305 (2005).\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eWeigend, F. Accurate coulomb-fitting basis sets for H to Rn, \u003cem\u003ePhys. Chem. Chem. Phys.\u003c/em\u003e \u003cstrong\u003e8\u003c/strong\u003e, 1057-1065 (2006).\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-3050761/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-3050761/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe synthesis of heteronuclear alkyne analogs incorporating heavier group 14 elements (R\u003csup\u003e1\u003c/sup\u003e−C≡E−R\u003csup\u003e2\u003c/sup\u003e, E = Si, Ge, Sn, Pb) has posed a longstanding challenge, with no previous reports on isolable compounds of this nature. Until now, neutral silynes (R\u003csup\u003e1\u003c/sup\u003e−C≡Si(L)−R\u003csup\u003e2\u003c/sup\u003e) and germynes (R\u003csup\u003e1\u003c/sup\u003e−C≡Ge(L)−R\u003csup\u003e2\u003c/sup\u003e) stabilized by a Lewis base have achieved sufficient stability for structural characterization at low temperatures. Here we show the isolation of a base-free stannyne (R\u003csup\u003e1\u003c/sup\u003e−C≡Sn−R\u003csup\u003e2\u003c/sup\u003e) at room temperature, achieved through the strategic use of a bulky cyclic phosphino ligand in combination with a bulky terphenyl substituent. Despite an allenic structure with strong delocalization of π-electrons, this compound exhibits adjacent ambiphilic carbon and tin centers, forming a unique carbon-tin multiple bond with ionic character. The stannyne demonstrates reactivity similar to carbenes or stannylenes, reacting with 1-adamantyl isocyanide and 2,3-dimethyl-1,3-butadiene. Additionally, its carbon-tin bond can be saturated by Et\u003csub\u003e3\u003c/sub\u003eN·HCl or cleaved by isopropyl isocyanate.\u003c/p\u003e","manuscriptTitle":"A crystalline stannyne","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-03 16:35:57","doi":"10.21203/rs.3.rs-3050761/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"nature-chemistry","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"nchem","sideBox":"Learn more about [Nature Chemistry](http://www.nature.com/nchem/)","snPcode":"","submissionUrl":"","title":"Nature Chemistry","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature Research","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"8de887a2-2160-4ee4-b4e8-e398b82300b1","owner":[],"postedDate":"April 3rd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":29867574,"name":"Physical sciences/Chemistry/Coordination chemistry/Organometallic chemistry/Chemical bonding"},{"id":29867575,"name":"Physical sciences/Chemistry/Chemical synthesis/Reactive precursors"}],"tags":[],"updatedAt":"2024-06-18T07:06:16+00:00","versionOfRecord":{"articleIdentity":"rs-3050761","link":"https://doi.org/10.1038/s41557-024-01555-4","journal":{"identity":"nature-chemistry","isVorOnly":false,"title":"Nature Chemistry"},"publishedOn":"2024-06-17 04:00:00","publishedOnDateReadable":"June 17th, 2024"},"versionCreatedAt":"2024-04-03 16:35:57","video":"","vorDoi":"10.1038/s41557-024-01555-4","vorDoiUrl":"https://doi.org/10.1038/s41557-024-01555-4","workflowStages":[]},"version":"v1","identity":"rs-3050761","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-3050761","identity":"rs-3050761","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}