Molecular-Squeeze Triggers Guest Desorption from Sponge-Like Macrocyclic Crystals

Molecular-Squeeze Triggers Guest Desorption from Sponge-Like Macrocyclic Crystals | 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 Molecular-Squeeze Triggers Guest Desorption from Sponge-Like Macrocyclic Crystals Kecheng Jie, Linnan Zhang, Lifeng Zheng, Yingying Song, Jingwei Huang, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4248303/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Desorption in conventional porous sorbents often employ external forces including inert gas blowing, heating, vacuum treatment to trigger guest release through competitive intermolecular interactions. We here report an unprecedented molecular–squeeze triggered guest release behavior from sponge–like macrocyclic crystals. The crystals function as typical sponge to include guest molecules within their microscopic voids that are adaptively formed, thus acting as adsorbents for toluene/pyridine separations. Intriguingly, vaporized ethyl acetate molecules trigger the guest release from the crystals without entering the pores or voids of the adsorbent to replace the guest. Instead, they work as external forces applied directly onto the crystals themselves, squeezing the materials to close the voids and release the guest molecules. Various experimental techniques as well as molecular dynamics simulations reveal the mechanism of the molecular–squeeze induced guest release procedure. The vapor–regenerated crystals can be recycled multiple times without the loss of separation performance. Compared with conventional guest release procedure, this method is manipulated in a mild condition, showing the potential in saving cost and energy. Physical sciences/Chemistry/Supramolecular chemistry/Crystal engineering Physical sciences/Chemistry/Materials chemistry Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Introduction Porous materials have long been recognized for their sponge–like ability to adsorb guest molecules within their internal pores at the molecular level. This property has positioned task–specific porous materials as valuable candidates for deployment in adsorptive separation processes, leveraging selective adsorption to achieve energy–efficient and environmentally friendly separation in the chemical industry 1–3 . An array of porous framework materials, including zeolites 4,5 , metal–organic frameworks (MOFs) 6–9 , covalent–organic frameworks (COFs) 10–12 , porous organic polymers (POPs) 13,14 , as well as porous molecular materials including porous organic cages (POCs) 15,16 and metal–organic polyhedra (MOPs) 17,18 , have been extensively investigated as adsorbents in adsorptive separation applications. In the context of energy–intensive adsorption separation processes, optimizing energy conservation hinges on the facile desorption or release of selectively–trapped guests, coupled with the efficient regeneration and recyclability of the adsorbents. Traditional desorption processes for porous materials involve inert gas or vacuum pump usage, often combined with heating treatment, known as temperature–swing adsorption (TSA) and pressure–swing adsorption (PSA) 19–23 . However, the substantial heat cost incurred due to either the high binding energy between the adsorbent and the guest or the high boiling point of the guest, resulting in elevated energy expenses that can be comparable to those associated with traditional distillation. Beyond conventional porous materials, we recently discovered a novel class of adsorbents based on macrocyclic crystals, which are termed as nonporous adaptive crystals (NACs) in terms of their unique properties 24–31 . These materials can function as sponges to adsorb guests in the solid–vapor phase. Triggered by guest vapors, these nonporous crystalline materials undergo a structural transformation, creating voids that are absent in their initial state to accommodate guest molecules. The adaptive property, combined with distinct host–guest interactions, facilitates the adsorption and separation of various hydrocarbons 32–43 . Despite achieving reversible adsorption and desorption within these materials, the release or desorption of trapped guests, along with material regeneration, remains energy–intensive. Prolonged and relatively high–temperature heating in a vacuum is essential for releasing guest molecules due to the strong binding between the guest and macrocycles, with hydrocarbons boasting high boiling points posing additional challenges for one–step desorption. In addition to guest uptake capability, another notable characteristic of typical sponges is their exceptional mechanical performance, enabling adaptation to external forces 44 . Consequently, desorption typically occurs in sponge–like soft adsorbents (e.g., sponges, towels, fabrics), where external forces such as squeezing, twisting, and screwing induce material deformation, compress voids, and ultimately release guests. However, the material squeeze method is challenging to apply to current adsorbents, including porous materials and NACs, the majority of which are hard solids in bulk and lack sufficient mechanical performance 45–49 . For these materials, external forces (inert gas, heating, vacuum) are often employed to interact with guests, triggering guest release through competitive intermolecular interactions (Scheme 1a). External forces applied to these host adsorbents for guest squeeze may prove ineffective or lead to material collapse. Despite the lack of softness in bulk, NACs exhibit flexibility at the molecular level, as evidenced by their transformable crystal structures upon adsorption and desorption 31 . We thus anticipated that applying soft external forces at the molecular level to squeeze the adsorbents might facilitate energy–efficient desorption. Herein, we present a molecular–squeeze–triggered guest release behavior in these sponge–like macrocyclic crystals, a phenomenon that has been unprecedented previously. These macrocyclic crystals operate similarly to typical sponges, accommodating guest molecules within adaptively formed voids, resulting in enhanced separation performance for the toluene/pyridine azeotrope. In contrast to conventional desorption methods, specific vaporized molecules can induce guest release from the guest–loaded crystals without penetrating the pores or voids. Instead, these vaporized molecules serve as external forces directly applied to the adsorbents, squeezing the crystals to close the voids and release the guest molecules (Scheme 1b). A combination of experimental techniques and molecular simulations unequivocally reveals the mechanism underlying the guest release process, emphasizing the significance of interactions between the vapor and the crystals. The fundamental principle is that these crystals tend to form the most thermodynamically stable, guest–free structures in the presence of these vapors. Compared to previous guest release methods 22 – 23 , this approach operates under mild conditions, ensuring high recyclability of the materials and consequently reducing both cost and energy consumption. Results and Discussion Synthesis, Characterizations and Phase Transitions of Desolvated pillar [ 5 ] arene [ 1 ] quinone (EtP5Q1) Crystals. The sponge–like macrocyclic crystals are composed of pure pillar[ 5 ]arene[ 1 ]quinone ( EtP5Q1 ) molecules (Fig. 1 a). EtP5Q1 was firstly synthesized as brownish red powders by partial oxidation of perethylated pillar[ 6 ]arene 25 . Heating the as–synthesized powders overnight at 80°C in vacuum afforded a desolvated sample, as confirmed by 1 H NMR and thermogravimetric analysis (TGA) data (Supplementary Figs. S1 and S2). Powder X–ray diffraction (PXRD) experiments showed its high crystallinity (Fig. 1 b and S3, referred to as EtP5Q1α ). Interestingly, recrystallization of the as–synthesized EtP5Q1 in ethyl acetate ( EA ) followed by a similar desolvation procedure afforded a new desolvated sample (Supplementary Figs. S4 and S5), which was demonstrated by PXRD to be a different polymorph of the material (referred to as EtP5Q1β , Fig. 1 b and S6). It is worth mentioning that polymorphism is common for molecular crystals but relatively rare for pillararene crystals 32–43 . N 2 adsorption experiments showed that both EtP5Q1α and EtP5Q1β had very low Brunauer–Emmett–Teller (BET) surface area, similar to the nonporous nature of other pillararene crystals (Supplementary Figs. S7 and S8). To get deeper understanding of the two polymorphs, attempts were made to obtain their single crystal structures. After several trials, single crystals of EtP5Q1 were successfully obtained using vapor diffusion of cyclohexane ( CH ) into a chloroform solution. These crystals were further characterized using single crystal X–ray diffraction (SC–XRD) and are referred to as CH @ EtP5Q1 . The structure of CH @ EtP5Q1 adopts a Cc space group. In this structure, one CH molecule is situated in the hexagonal cavity center of EtP5Q1 , forming a 1:1 host–guest complex. The stabilization of this complex is achieved through multiple CH···π interactions (Fig. 1 c). The packing mode reveals that no interconnected channels are formed within the structure; instead, a staggered packing arrangement is observed (Fig. 1 c, right). It is noteworthy that direct desolvation of a CH @ EtP5Q1 single crystal resulted in its destruction into crystalline powders. This challenging outcome made it difficult to elucidate the structure of desolvated EtP5Q1 through single crystal X–ray diffraction (SC–XRD). However, the PXRD patterns between EtP5Q1α and the desolvated CH @ EtP5Q1 were almost identical, implying that they are the same phase (Supplementary Fig. S9). Meanwhile, compared with the PXRD pattern simulated from CH @ EtP5Q1 , the pattern of EtP5Q1α remains almost unchanged with an exception that the diffraction peaks appear at slightly lower scattering angles (Supplementary Fig. S9). This is a typical phenomenon that the crystal lattice undergoes a slight expansion without changing the unit cell parameters, which on the other hand confirms the structural similarity between EtP5Q1α and CH @ EtP5Q1 (Fig. 1 e). Luckily, single crystals of EtP5Q1 were also obtained by slow evaporation of an EA solution. As characterized by SC–XRD, the crystal structure has P –1 space group. Different from CH @ EtP5Q1 , no EA molecules can be found within the structure, indicating a desolvated phase (Fig. 1 d). EtP5Q1 molecules adopt a densely–packing mode, where one of the p –diethoxybenzene subunits rotates along the methylene axis into the cavity and is further stabilized by intramolecular CH···π interaction. EtP5Q1 molecules are thus deformed with dense packing. The PXRD pattern simulated from the single crystal structure shows a good agreement with the experimental one of EtP5Q1β (Supplementary Fig. S10), confirming that they are the same phase. This also indicates that recrystallization of EtP5Q1 from EA could afford EtP5Q1β without further desolvation. The phase transition between the two polymorphs were then explored. Our previous studies show that pillararene crystals can act as adsorbents to adsorb vaporized guests along with crystal structure transitions 24 . We first exposed EtP5Q1α to CH vapor and observed that adsorption of CH as well as crystal lattice shrinkage occurred (Figs. 1 e, S11 and S12). However, when EtP5Q1β crystals were exposed to CH vapor, neither CH adsorption nor crystal structure transition occurred, implying that the structure transition from EtP5Q1β to EtP5Q1α cannot be achieved (Figs. 1 e, S13 and S14). Interestingly, when EtP5Q1α was exposed to EA vapor, the PXRD pattern as well as 1 H NMR spectrum showed a clear phase transition from EtP5Q1α to EtP5Q1β without the adsorption of EA (Figs. 1 e, S15 and S16), which is unprecedented previously. This behavior is similar to sponges where EA acts as external forces to trigger the material deformation at the molecular level. In the context of differential scanning calorimetry (DSC) analysis, the obtained curves revealed distinctive thermal behavior for EtP5Q1α and EtP5Q1β (Supplementary Fig. S17). Specifically, EtP5Q1α exhibited two discernible endothermic peaks, occurring at 137°C and 165°C, respectively. In contrast, EtP5Q1β displayed a singular endothermic peak at 165°C. This DSC data unequivocally establishes that the endothermic peak at 137°C in EtP5Q1α corresponds to a phase transition, while the peaks at 165°C signify the melting points of EtP5Q1 crystals. The presence of a single endothermic peak in EtP5Q1β at the higher temperature suggests that it is the thermodynamically more stable polymorph than EtP5Q1α . Adsorption and Separation Performance of the Two EtP5Q1 Polymorphs. Given the observed phase transitions and the cavity size of EtP5Q1 , we conducted adsorption experiments with common cyclic hydrocarbons, including CH , benzene ( Bz ), toluene ( Tol ), and pyridine ( Py ), utilizing the two polymorphs of EtP5Q1 . The single–component vapor sorption isotherms (Fig. 2 ) reveal that both polymorphs function as adsorbents to effectively adsorb all four hydrocarbons, albeit with variations in adsorption capacity and kinetics. Notably, for Bz , the adsorption capacity and kinetics were similar in both EtP5Q1α and EtP5Q1β (Fig. 2 b). In contrast, the adsorption amounts of the other three guests in EtP5Q1α were nearly twice those in EtP5Q1β , underscoring the pivotal role of crystalline phases in dictating the adsorption behavior of molecular crystals. It is crucial to highlight the presence of hysteresis loops in the desorption process, indicating a notable challenge in the release of adsorbed hydrocarbons. Even under reduced pressure, a certain amount of hydrocarbons remained trapped, indicating the high binding strength between EtP5Q1 crystals and hydrocarbon guests. Consequently, the desorption process proves to be energy–consuming, posing a potential limitation if these materials were to be applied as adsorbents in adsorptive separation processes. 1 H NMR and TGA further confirmed the adsorption and storage of these hydrocarbons in EtP5Q1α and EtP5Q1β . The uptake of CH , Py , Bz and Tol can be calculated to be one molecule per EtP5Q1 molecule (mole/ EtP5Q1 ) in EtP5Q1α , respectively. The uptake of Py and Bz in EtP5Q1β is similar to that of EtP5Q1α while the uptake of CH and Tol is negligible (Supplementary Figs. S18−S29). PXRD experiments were carried out to investigate the structures of EtP5Q1α and EtP5Q1β after uptake of the hydrocarbons. The PXRD patterns of EtP5Q1α became different after adsorption of the four hydrocarbons (Supplementary Fig. S30), indicating the formation of new EtP5Q1 structures. Similarly, the PXRD patterns of EtP5Q1β after uptake of Py and Bz were different from the original one, implying the formation of new EtP5Q1 structures (Supplementary Fig. S31), while the patterns remained unchanged upon exposure to CH and Tol (Supplementary Fig. S32). It is worth noting that the patterns of EtP5Q1α and EtP5Q1β after adsorption of Py or Bz are almost the same with each other, respectively, meaning that two original phases switch to the same crystal structure after adsorption of the same guest (Supplementary Figs. S33 and S34). To reveal these new structures, hydrocarbon–loaded single crystal structures of EtP5Q1 were obtained. In the crystal structure of Bz –loaded EtP5Q1 ( Bz 2 @ EtP5Q1 , Fig. 3 a), one Bz molecule was loaded inside the cavity center of EtP5Q1 with the other Bz molecule trapped in the extrinsic space of EtP5Q1 (Fig. 3 a, middle), forming a 2:1 complex crystal. Similarly, in the analogous Tol –loaded crystal structure of EtP5Q1 ( Tol 2 @ EtP5Q1 , Fig. 3 b), a Tol molecule is located in the center of the EtP5Q1 cavity, while the other one is located in the extrinsic space of EtP5Q1 molecules (Fig. 3 b), also forming a 2:1 complex crystal. In Py –loaded EtP5Q1 crystal structure ( Py 3 @ EtP5Q1 , Fig. 3 c), all three Py molecules are located in the cavity of EtP5Q1 , forming a 1:3 host–guest complex (Fig. 3 c, middle), which is rarely observed in pillararene–based host–guest systems 26 . The window–to–window packing mode of hexagonal EtP5Q1 molecules in Py 3 @ EtP5Q1 contributes to the formation of honeycomb–like infinite 1D channels (Fig. 3 c, right). We proceeded to investigate whether EtP5Q1α and EtP5Q1β could effectively discriminate between mixtures of CH and Bz or mixtures of Tol and Py , both of which hold significant relevance in the chemical industry. To assess selectivity, time–dependent solid–vapor sorption experiments were conducted using a 1:1 volumetric ratio of Bz : CH or Tol : Py . In the case of CH / Bz separation, neither EtP5Q1α nor EtP5Q1β exhibited selective uptake of Bz or CH , as evidenced by NMR analyses (Supplementary Figs. S35 and S36). However, in the Tol / Py separation scenario, both EtP5Q1α and EtP5Q1β demonstrated remarkable selectivity towards Py (Fig. 4 a and 4 b). The sole difference lay in sorption kinetics, with the uptake rate of Py in EtP5Q1α being slightly faster than that in EtP5Q1β . Gas chromatography (GC) experiments indicated that the percentages of Py adsorbed in EtP5Q1α and EtP5Q1β were 99.7% and 99.5%, respectively (Supplementary Figs. S37 and S38). The PXRD patterns of both EtP5Q1α and EtP5Q1β after adsorption of the Tol / Py mixture align with that simulated from Py 3 @ EtP5Q1 (Supplementary Fig. S33), underscoring structural transformations from the original phases to Py 3 @ EtP5Q1 , respectively (Fig. 4 c). This attests to the potential of EtP5Q1α and EtP5Q1β as promising candidates for the selective separation of Tol / Py mixtures, offering valuable applications in chemical processes. Vapor–Triggered Guest Release. The ease of guest release is a critical consideration in practical adsorptive separation processes, as this step typically accounts for the majority of energy consumption in the overall process. However, the formidable binding between the guest and EtP5Q1 presents a challenge in releasing adsorbates from EtP5Q1 crystals. This challenge is evident in the vapor desorption isotherm, where a substantial amount of guests cannot be released from the crystals even under reduced pressure (Fig. 2 ). This difficulty is not unique to EtP5Q1 crystals but is a common issue encountered with other crystalline adsorbents based on pillararenes and macrocycles 24 . Previous studies have indicated that only prolonged heating at elevated temperatures in a vacuum environment could effectively release adsorbates 27 . In the case of Py , for instance, only overnight heating at an elevated temperature in a vacuum could achieve desorption. This process is undeniably energy–intensive and time–consuming, presenting a significant barrier to the practical application of these materials in real production scenarios. Additionally, the challenging conditions make the collection of the desorbed guest extremely difficult. Therefore, there is a pressing need to develop new and more efficient desorption methods for these materials to enhance their practical utility in industrial applications. The intriguing phase transition observed from EtP5Q1α to EtP5Q1β triggered by EA vapor has captured our attention, as EA essentially functions as an external force to induce molecular–level deformation inside the crystals. This raises a compelling question: could EA trigger the phase transition of guest–loaded EtP5Q1 crystals to EtP5Q1β , potentially leading to the desorption of guests through structural deformation? Given the structural similarity between EtP5Q1α and CH @ EtP5Q1 , we conducted an initial experiment by exposing CH @ EtP5Q1 to EA vapor at room temperature. Surprisingly, time–dependent 1 H NMR spectra revealed a gradual decrease in the content of CH within CH @ EtP5Q1 , eventually disappearing entirely after 150 minutes (Fig. 5 a). Concurrently, ex situ PXRD patterns demonstrated a time–dependent transformation process in the PXRD pattern of CH @ EtP5Q1 , ultimately converging to the same pattern as that of EtP5Q1β (Fig. 5 b). These findings collectively indicate that EA vapor has the ability to trigger the release of CH from CH @ EtP5Q1 under ambient conditions, accompanied by the phase transition from CH –loaded CH @ EtP5Q1 to guest–free EtP5Q1β (Fig. 5 c). Subsequent experiments involving other guest–loaded EtP5Q1 crystals were conducted with the anticipation that the observed phenomenon with CH in CH @ EtP5Q1 could be extended to different guests. Exposure to EA vapor at ambient conditions resulted in similar outcomes for Py 3 @ EtP5Q1 and Bz 2 @ EtP5Q1 . Time–dependent 1 H NMR spectra revealed a gradual decrease in the content of Bz within Bz 2 @ EtP5Q1 and Py within Py 3 @ EtP5Q1 , respectively (Fig. 6 a and 6 b). The absence of these guest molecules within the crystals post–exposure to EA vapor was also confirmed by 1 H NMR spectra and TGA curves (Supplementary Figs. S41−S45). Additionally, the PXRD patterns of these guest–loaded crystals all transitioned to match that of EtP5Q1β after exposure to EA vapor (Figs. 6 c, S40 and S43). These comprehensive characterizations collectively indicate that regardless of the nature of the guest molecules included in EtP5Q1 crystals, EA vapor has the remarkable capability to trigger their release from the crystals without necessitating entry into the pores. To uncover the unconventional desorption mechanism, we systematically investigated a dozen molecules structurally similar to EA and explored their ability to induce guest release from CH @ EtP5Q1 . Table S1 summarizes the results obtained from PXRD experiments, demonstrating the squeeze–induced guest release properties of these molecules. Notably, molecules with similar or longer chain lengths and bearing ketone groups on the chain exhibited the same capacity as EA to trigger CH release, as evidenced by PXRD experiments (Supplementary Fig. S46). Diethyl ether, lacking ketone groups, was the sole exception among the molecules that can initiate CH release. Conversely, molecules with shorter chain lengths or lacking ketone groups were unable to induce guest release from EtP5Q1 crystals. This observation implies that both the functional groups and chain length play crucial roles in conferring the molecule's ability to function as a squeeze force, triggering guest release from the crystalline structure. Guest Release Mechanism. To further understand how the vapor triggers the guest release along with the structural transition, we carried out binding/lattice energy calculations. As shown in Table S3 and S4, the calculated energy of EtP5Q1β is lower than EtP5Q1α , indicating that EtP5Q1β is the thermodynamically more stable polymorph, which is consistent with the experimental result. Molecular dynamics (MD) simulations also revealed the configuration transition from guest–loaded EtP5Q1 structures to EtP5Q1β in EA atmosphere (Fig. 7 ). For instance, in the case of CH @ EtP5Q1 , the host–guest intermolecular distance is gradually increased during MD simulations. And at about 10 ns, the backbone of pillar–shape EtP5Q1 collapsed and changed to the deformed configuration within EtP5Q1β , along with CH release from the cavity as well as the unit cell, whereas EA molecules neither enter the cavity nor the crystal lattice in the whole simulation procedure. Instead, EA molecules function more likely as external force to squeeze and deform the hexagonal EtP5Q1 and close the cavity in the end (Fig. 7 a). This behavior further confirms the guest release is triggered via molecular squeeze rather than competitive guest–host or gust–guest interactions. Meanwhile, the similar dynamics simulation results were also observed for Bz 2 @ EtP5Q1 and Py 3 @ EtP5Q1 in the presence of EA vapor (Fig. 7 b and 7 c), further confirming the universality of the molecular squeeze triggered guest release behavior in these sponge–like crystals. Recyclability of EA–Regenerated EtP5Q1β Crystals. For an adsorbent to be practically useful, it must exhibit consistent and reliable performance over multiple cycles without degradation. In a previous demonstration, we illustrated that the material could be reproduced through long–term heating in a vacuum. However, this method is both energy and time–consuming. An important question arises regarding whether the vapor–regenerated EtP5Q1β crystals can be recycled effectively in the separation process. Conducting repeated experiments in Tol / Py separation, we found that the vapor–regenerated EtP5Q1β crystals maintained their separation performance over at least five cycles without any loss in efficiency (Fig. 8 ). This highlights the potential of our method as a rapid and efficient route to achieve adsorbent recyclability, addressing a critical aspect for the practical application of these materials in adsorptive separation processes. In conclusion, a molecular–squeeze triggered guest release behavior from sponge–like macrocyclic crystals was reported for the first time. The material functions akin to a typical sponge by encapsulating guest molecules within adaptively formed voids, serving as adsorbents for separating toluene and pyridine. Interestingly, vaporized EA molecules could trigger the guest release from the sponge without entering the pores or voids of the adsorbent to replace the guest. Instead, they work as external forces applied directly onto the adsorbents themselves, squeezing the materials to close the voids and release the guest molecules. Through various experimental techniques and molecular dynamics simulations, the mechanism behind the molecular–squeeze guest release process was elucidated. The regenerated material from vapor–induced release can be recycled multiple times without compromising separation performance. Compared to conventional guest release methods, this approach operates under mild conditions, leading to cost and energy savings. This discovery not only provides inspiration to develop new desorption process and mechanism, but also suggests the possibility of utilizing external forces to squeeze other soft crystalline adsorbents such as flexible MOFs and soft porous crystals for energy–efficient desorption process. Declarations Data availability The data generated in this study are provided in this article and Supplementary Information file. Additional data are available from the corresponding author upon request. Crystallographic data for Tol 2 @EtP5Q1 , EtP5Q1 β , Py 3 @EtP5Q1 , CH @ EtP5Q1 and Bz 2 @EtP5Q1 have been deposited at the Cambridge Crystallographic Data Centre (www.ccdc.cam.ac.uk/data_request/cif) and could be downloaded free of charge by the deposition number of 2339419, 2339420, 2339421, 2339422 and 2339423, respectively. Acknowledgements This work was supported by the Natural Science Foundation of China (22301131 and 22033004), the Natural Science Foundation of Jiangsu Province (BK20220781), the Fundamental Research Funds for the Central Universities (020514380285), and the State Key Laboratory of Coordination Chemistry (119001). Author contributions L.Z. and K.J. conceived the project and designed the experiments. L.Z. and Y.S. conducted the synthesis, adsorption and separation experiments. L.N.Z. performed vapor–triggered guest release experiments and analyzed the data. L.F.Z. and J.M. performed the theoretical calculation and analyzed data. L.Z.N, J.M., K.J. co-wrote the paper. L.N.Z., L.F.Z., J.H., H.N., J.M. and K.J. discussed the results and commented on the manuscript. Competing interests The authors declare no competing interests. Additional information The authors declare no competing financial interests. Supplementary information accompanies this paper at https://www.nature.com/natchemeng. Reprints and permission information is available online at http://www.nature.com/reprints. Correspondence and requests for materials should be addressed to K.J. References Sholl, D. S. & Lively, R. P. Seven Chemical Separations to Change the World. Nature 532 , 435–437 (2016). Wu, Y. & Weckhuysen, B. M. Separation and Purification of Hydrocarbons with Porous Materials. Angew. Chem. Int. Ed. 60 , 18930–18949 (2021). Farmahini, A. H., Krishnamurthy, S., Friedrich, D., Brandani, S. & Sarkisov, L. Performance–Based Screening of Porous Materials for Carbon Capture. Chem. Rev. 121 , 10666–10741 (2021). Ma, X., Kumar, P., Daoutidis, P., Mkhoyan, K. A. & Tsapatsis, M. Zeolitic imidazolate framework membranes made by ligand–induced permselectivation. Science 361 , 1008–1011 (2018). Pérez-Botella, E., Valencia, S. & Rey, F. Zeolites in Adsorption Processes: State of the Art and Future Prospects. Chem. Rev. 122 , 17647–17695 (2022). Zhao, X., Wang, Y., Li, D. S., Bu, X. & Feng, P. Metal–Organic Frameworks for Separation. Adv. Mater. 30 , 1705189 (2018). Cui, W. G., Hu, T. L. & Bu, X. H. Metal–Organic Framework Materials for the Separation and Purification of Light Hydrocarbons. Adv. Mater. 32 , 1806445 (2019). Qian, Q., Asinger, P. A., Lee, M. J., Chi, W. S. & Smith, Z. P. MOF–Based Membranes for Gas Separations. Chem. Rev. 120 , 8161–8266 (2020). Wang, H., Liu, Y. & Li, J. Designer Metal–Organic Frameworks for Size–Exclusion–Based Hydrocarbon Separations: Progress and Challenges. Adv. Mater. 32 , 2002603 (2020). Wang, Z., Zhang, S., Chen, Y., Zhang, Z. & Ma, S. Covalent organic frameworks for separation applications. Chem. Soc. Rev. 49 , 708–735 (2020). Geng, K. et al. Covalent Organic Frameworks: Design, Synthesis, and Functions. Chem. Rev. 120 , 8814–8933 (2020). Yuan, S., Li, X., Zhang, G., Van Puyvelde, P. & Van der Bruggen, B. Covalent organic frameworks for membrane separation. Chem. Soc. Rev. 48 , 2665–2681 (2019). Song, K. S., Fritz, P. W. & Coskun, A. Porous organic polymers for CO 2 capture, separation and conversion. Chem. Soc. Rev. 51 , 9831–9852 (2022). Wu, J., Xu, F., Fu, R. & Wu, D. Porous Polymers as Multifunctional Material Platforms toward Task-Specific Applications. Adv. Mater. 31 , 1802922 (2018). Yang, X., Ullah, Z., Stoddart, J. F. & Yavuz, C. T. Porous Organic Cages. Chem. Rev. 123 , 4602–4634 (2023). Liu, M., Zhang, L., Ceriotti, M., Hirscher, M. & Cooper, A. I. Barely porous organic cages for hydrogen isotope separation. Science 366 , 613–620 (2019). Gosselin, A. J., Rowland, C. A. & Bloch, E. D. Permanently Microporous Metal–Organic Polyhedra. Chem. Rev. 120 , 8987–9014 (2020). Guo, X., Xu, S., Huang, H. & Zhong, C. Metal–organic polyhedron membranes for molecular separation. J. Membr. Sci. 632 , 119354 (2021). Ren, T., Patel, M. & Blok, K. Olefins from conventional and heavy feedstocks: Energy use in steam cracking and alternative processes. Energy 31 , 425–451 (2006). Wang, S.-M., Shivanna, M., Space, B., Kitagawa, S. & Zaworotko, M. J. Ethane/Ethylene Separations in Flexible Diamondoid Coordination Networks via an Ethane–Induced Gate–Opening Mechanism. J. Am. Chem. Soc. 146 , 4153–4161 (2024). Gu, C., Hosono, N., Kusaka, S., Sakaki, S. & Kitagawa, S. Design and control of gas diffusion process in a nanoporous soft crystal. Science 363 , 387–391 (2019). Lin, Y., Yu, L., Xia, Q., Thonhauser, T. & Li, J. Temperature-Programmed Separation of Hexane Isomers by a Porous Calcium Chloranilate Metal-Organic Framework. Angew. Chem. Int. Ed. 61 , e202214060 (2022). Xia, W., Yang, Y., Yang, Q., Ren, Q. & Bao, Z. Temperature–dependent molecular sieving of fluorinated propane/propylene mixtures by a flexible–robust metal–organic framework. Sci. Adv. 10 , eadj6473 (2024). Jie, K., Zhou, Y., Li, E. & Huang, F. Nonporous Adaptive Crystals of Pillararenes. Acc. Chem. Res. 51 , 2064–2072 (2018). Ogoshi, T., Yamagishi, T.-a. & Nakamoto, Y. Pillar–Shaped Macrocyclic Hosts Pillar[n]arenes: New Key Players for Supramolecular Chemistry. Chem. Rev. 116 , 7937–8002 (2016). Wu, J. R. & Yang, Y. W. Synthetic Macrocycle-Based Nonporous Adaptive Crystals for Molecular Separation. Angew. Chem. Int. Ed. 60 , 1690-1701 (2020). Jie, K., Liu, M., Chen, L., Huang, F. & Cooper, A. I. Styrene Purification by Guest–Induced Restructuring of Pillar[6]arene. J. Am. Chem. Soc. 139 , 2908–2911 (2017). Adachi, K., Fa, S., Akine, S. & Ogoshi, T. Adaptive Planar Chirality of Pillar[5]arenes Invertible by n –Alkane Lengths. J. Am. Chem. Soc. 145 , 8114–8121 (2023). Ogoshi, T., Saito, K., Kakuta, T. & Yamagishi, T. a. Separation of Linear and Branched Alkanes Using Host–Guest Complexation of Cyclic and Branched Alkane Vapors by Crystal State Pillar[6]arene. Angew. Chem. Int. Ed. 57 , 1592–1595 (2018). Jie, K., Zhou, Y., Li, E., Zhao, R. & Huang, F. Separation of Aromatics/Cyclic Aliphatics by Nonporous Adaptive Pillararene Crystals. Angew. Chem. Int. Ed. 57 , 12845–12849 (2018). Jie, K., Liu, M., Day, G. M., Huang, F. & Cooper, A. I. Near–Ideal Xylene Selectivity in Adaptive Molecular Pillar[n]arene Crystals. J. Am. Chem. Soc. 140 , 6921–6930 (2018). Zhu, H., Chen, L., Li, H., Stoddart, J. F. & Huang, F. Applications of macrocycle–based solid–state host–guest chemistry. Nat. Rev. Chem. 7 , 768–782 (2023). Li, Q., Zhu, H. & Huang, F. Pillararene–Based Supramolecular Functional Materials. Trends Chem. 2 , 850–864 (2020). Ogoshi, T. Pillar–Shaped Macrocyclic Hosts Pillar[ n ]arenes: From Simple Receptors to Supramolecular Assemblies. AsiaChem Magazine 2 , 72–79 (2021). Zeng, F., Cheng, L., Zhang, W.-J., Tang, L.-L. & Wang, X.-F. Phenanthrene[2]arene: synthesis and application as nonporous adaptive crystals in the separation of benzene from cyclohexane. Org. Chem. Front. 9 , 3307–3311 (2022). Li, M., Shao, L., Khashab, N. M., Hua, B. & Huang, F. Cis – Trans and Length–Selective Molecular Discrimination of Halogenated Organic Compounds by a Crystalline Hybrid Macrocyclic Arene. ACS Appl. Mater. Interfaces 16 , 6614–6622 (2024). Ding, Y., Alimi, L. O., Jacquemin, J., Huang, F. & Khashab, N. M. Selective adsorptive separation of cyclohexane over benzene using thienothiophene cages. Chem. Sci. 12 , 5315–5318 (2021). Zhao, Y., Xiao, H., Tung, C.-H., Wu, L.-Z. & Cong, H. Adsorptive separation of cyclohexanol and cyclohexanone by nonporous adaptive crystals of RhombicArene. Chem. Sci. 12 , 15528–15532 (2021). Yang, W., Samanta, K., Zuilhof, H. & Sue, A. C. H. Tiara[5]arenes: Synthesis, Solid‐State Conformational Studies, Host-Guest Properties, and Application as Nonporous Adaptive Crystals. Angew. Chem. Int. Ed. 59 , 3994-3999 (2020). Wu, J.-R. & Yang, Y.-W. Geminiarene: Molecular Scale Dual Selectivity for Chlorobenzene and Chlorocyclohexane Fractionation. J. Am. Chem. Soc. 141 , 12280–12287 (2019). Wu, J., Li, B. & Yang, Y. Separation of Bromoalkanes Isomers by Nonporous Adaptive Crystals of Leaning Pillar[6]arene. Angew. Chem. Int. Ed. 59 , 2251–2255 (2019). Wang, Y., Xu, K., Fang J. & Li. C. Efficient Separation of cis - and trans -1,2-Dichloroethene Isomers by Adaptive Biphen[3]arene Crystals. Angew. Chem. Int. Ed. 58 , 10281-10284 (2019). Luo, D., Tian, J., Sessler, J. L. & Chi, X. Nonporous Adaptive Calix[4]pyrrole Crystals for Polar Compound Separations. J. Am. Chem. Soc. 143 , 18849–18853 (2021). Jiang, Y., Tan, P., Liu, X.-Q. & Sun, L.-B. Breathing Metal–Organic Polyhedra Controlled by Light for Carbon Dioxide Capture and Liberation. CCS Chem. 3 , 1659–1668 (2021). Lin, R.-B., Xiang, S., Zhou, W. & Chen, B. Microporous Metal–Organic Framework Materials for Gas Separation. Chem 6 , 337–363 (2020). Lin, R.-B., He, Y., Wang, H., Zhou, W. & Chen, B. Multifunctional porous hydrogen–bonded organic framework materials. Chem. Soc. Rev. 48 , 1362–1389 (2019). Zhang, D., Ronson, T. K., Zou, Y.–Q. & Nitschke, J. R. Metal–organic cages for molecular separations. Nat. Rev. Chem. 5 , 168–182 (2021). Herm, Z. R., Wiers, B. M., Mason, J. A., Krishna, R. & Long, J. R. Separation of Hexane Isomers in a Metal–Organic Framework with Triangular Channels. Science 340 , 960–964 (2013). Li, L., Lin, R.-B., Li, J., Zhou, W. & Chen, B. Ethane/ethylene separation in a metal–organic framework with iron–peroxo sites. Science 362 , 443–446 (2018). Scheme Scheme 1 is available in the Supplementary Files section. Additional Declarations There is NO Competing Interest. Supplementary Files SIsqueezetriggeredrelease.docx SUPPLEMENTARY INFORMATION Scheme1.png Scheme 1. Schematic representation of (a) conventional guest desorption methods; (b) guest desorption from sponge–like macrocyclic crystals by molecular squeeze induced deformation. Cite Share Download PDF Status: Posted 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. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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-4248303","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":302810299,"identity":"e132523d-b7c4-4c6f-9731-10579f7d1bff","order_by":0,"name":"Kecheng Jie","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA80lEQVRIiWNgGAWjYBACxmYGZiB1AIiZDzBIMEDZRGphSyBOC8h0qDIeAwifkBbmdubDBh9q7siZ86/59sCyjUGO70YC4+cCvA5jS06cceyZseWMt9sNJNsYjCVvJDBLz8Crhcf4MG/D4cQNN85ukwBqATIS2Jh58Grh/3z4b8Ph+g03zjwDaaknQgsPczJjw+EEg/M9bCAtCQaEtbAZG/YcO2y44QabmYTEOQnDmWceNkvj02LYf/ixxI+aw/IG5w8/k5Yos5HnO5588DNeLQ0wlkQCA7MEODIZG3AqBwF5OIv/AAPjB7xqR8EoGAWjYKQCAAW+To0UE8AnAAAAAElFTkSuQmCC","orcid":"","institution":"Nanjing University","correspondingAuthor":true,"prefix":"","firstName":"Kecheng","middleName":"","lastName":"Jie","suffix":""},{"id":302810300,"identity":"bad6655f-21fe-459b-a961-30b79cdf17c8","order_by":1,"name":"Linnan Zhang","email":"","orcid":"","institution":"Nanjing University","correspondingAuthor":false,"prefix":"","firstName":"Linnan","middleName":"","lastName":"Zhang","suffix":""},{"id":302810301,"identity":"bc99c677-cfa3-4d6f-bf6c-1c2ac7c5212a","order_by":2,"name":"Lifeng Zheng","email":"","orcid":"","institution":"Nanjing University","correspondingAuthor":false,"prefix":"","firstName":"Lifeng","middleName":"","lastName":"Zheng","suffix":""},{"id":302810302,"identity":"35208f72-be15-4d52-a886-4ff1ad79570e","order_by":3,"name":"Yingying Song","email":"","orcid":"","institution":"Nanjing University","correspondingAuthor":false,"prefix":"","firstName":"Yingying","middleName":"","lastName":"Song","suffix":""},{"id":302810303,"identity":"1906e449-c5b4-4e3c-931c-4172068ca897","order_by":4,"name":"Jingwei Huang","email":"","orcid":"","institution":"Nanjing University","correspondingAuthor":false,"prefix":"","firstName":"Jingwei","middleName":"","lastName":"Huang","suffix":""},{"id":302810304,"identity":"823e0ecd-0b74-4ecd-8e01-2b01de535d95","order_by":5,"name":"Hailong Ning","email":"","orcid":"","institution":"Nanjing University","correspondingAuthor":false,"prefix":"","firstName":"Hailong","middleName":"","lastName":"Ning","suffix":""},{"id":302810305,"identity":"b9a3f5e8-7fb7-4ebc-b2ee-3b07c6c2602b","order_by":6,"name":"Leyong Wang","email":"","orcid":"https://orcid.org/0000-0001-5775-3714","institution":"Nanjing University","correspondingAuthor":false,"prefix":"","firstName":"Leyong","middleName":"","lastName":"Wang","suffix":""},{"id":302810306,"identity":"17100231-ada9-451a-8320-f09c3f02e7e2","order_by":7,"name":"Jing Ma","email":"","orcid":"https://orcid.org/0000-0001-5848-9775","institution":"Nanjing University","correspondingAuthor":false,"prefix":"","firstName":"Jing","middleName":"","lastName":"Ma","suffix":""}],"badges":[],"createdAt":"2024-04-10 15:50:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4248303/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4248303/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":56595461,"identity":"454f8347-6671-4275-9d09-69667b8d11a2","added_by":"auto","created_at":"2024-05-16 10:20:03","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1128479,"visible":true,"origin":"","legend":"\u003cp\u003eChemical structures of (a) \u003cstrong\u003eEtP5Q1\u003c/strong\u003e; (b) PXRD patterns: (I) \u003cstrong\u003eEtP5Q1\u003c/strong\u003eα and (II) \u003cstrong\u003eEtP5Q1\u003c/strong\u003eβ; (c) single crystal structures of (c) \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e and (d) \u003cstrong\u003eEtP5Q1\u003c/strong\u003eβ; (e) schematic representation of phase transitions among \u003cstrong\u003eEtP5Q1\u003c/strong\u003eα, \u003cstrong\u003eEtP5Q1\u003c/strong\u003eβ and \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e.\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/3ae2478600f8d4d42b4ab949.png"},{"id":56595462,"identity":"f3fc706e-880e-42b0-bd65-9796818afdcc","added_by":"auto","created_at":"2024-05-16 10:20:03","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":189555,"visible":true,"origin":"","legend":"\u003cp\u003eVapor sorption isotherms of (a) \u003cstrong\u003eCH\u003c/strong\u003e, (b) \u003cstrong\u003eBz\u003c/strong\u003e, (c) \u003cstrong\u003ePy\u003c/strong\u003e and (d) \u003cstrong\u003eTol\u003c/strong\u003eusing \u003cstrong\u003eEtP5Q1\u003c/strong\u003eα and \u003cstrong\u003eEtP5Q1\u003c/strong\u003eβ, respectively.\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/8e4cd3293dc9d06c6a593434.png"},{"id":56595464,"identity":"9b964dbd-0227-452c-a0f4-c02c2c04a132","added_by":"auto","created_at":"2024-05-16 10:20:03","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1379600,"visible":true,"origin":"","legend":"\u003cp\u003eSingle crystal structures: (a) \u003cstrong\u003eBz\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e; (b) \u003cstrong\u003eTol\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e; (c)\u0026nbsp;\u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e.\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/c86ddd2125ff67864deef8b3.png"},{"id":56595465,"identity":"f604137e-d424-44fe-b0a2-5bf42c561162","added_by":"auto","created_at":"2024-05-16 10:20:03","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":362409,"visible":true,"origin":"","legend":"\u003cp\u003eTime–dependent solid–vapor sorption plot for \u003cstrong\u003eTol/Py\u003c/strong\u003e mixture vapor using (a)\u003cstrong\u003e EtP5Q1\u003c/strong\u003eα and \u003cstrong\u003eEtP5Q1\u003c/strong\u003eβ; (c) schematic representation of structural transformation from \u003cstrong\u003eEtP5Q1α\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u003c/strong\u003eβ to \u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e upon capture of \u003cstrong\u003eTol\u003c/strong\u003e/\u003cstrong\u003ePy\u003c/strong\u003e mixture vapor.\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/c2503a55c2a6e2b1772cc9d1.png"},{"id":56595467,"identity":"90ca16e1-3dd5-4c9e-8e46-f4ed5d2892c6","added_by":"auto","created_at":"2024-05-16 10:20:03","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":510442,"visible":true,"origin":"","legend":"\u003cp\u003e(a) Time–dependent \u003cstrong\u003eCH\u003c/strong\u003e content within \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals; (b)\u003cem\u003e \u003c/em\u003etime–dependent\u003cem\u003e \u003c/em\u003ePXRD patterns of \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e upon exposure \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1 \u003c/strong\u003eto \u003cstrong\u003eEA\u003c/strong\u003e vapor: (I) \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e; \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e after exposure to \u003cstrong\u003eEA\u003c/strong\u003e vapor for (II) 30 min, (III)\u003cstrong\u003e \u003c/strong\u003e60 min, (IV) 90 min, (V) 120 min, (VI) 150 min and (VII) \u003cstrong\u003eEtP5Q1\u003c/strong\u003eβ; (c) schematic representation of structural transformation from\u003cstrong\u003e CH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1 \u003c/strong\u003eto \u003cstrong\u003eEtP5Q1\u003c/strong\u003eβ upon exposure to \u003cstrong\u003eEA\u003c/strong\u003e vapor.\u003c/p\u003e","description":"","filename":"image6.png","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/a746580adfcde2ccbd7f9766.png"},{"id":56595466,"identity":"f44451c2-44c9-4ea9-8a1e-b48d38c57d1c","added_by":"auto","created_at":"2024-05-16 10:20:03","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":444590,"visible":true,"origin":"","legend":"\u003cp\u003eTime–dependent (a) \u003cstrong\u003ePy\u003c/strong\u003e content within \u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals and (b)\u003cem\u003e \u003c/em\u003e\u003cstrong\u003eBz\u003c/strong\u003e content within \u003cstrong\u003eBz\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals upon exposure\u003cstrong\u003e \u003c/strong\u003eto \u003cstrong\u003eEA\u003c/strong\u003e vapor; (c) schematic representation of structural transformation from\u003cstrong\u003e Py\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e and \u003cstrong\u003eBz\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e to \u003cstrong\u003eEtP5Q1\u003c/strong\u003eβ upon exposure to \u003cstrong\u003eEA\u003c/strong\u003e vapor.\u003c/p\u003e","description":"","filename":"image7.png","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/5f2524cad9f5cfb553b45d53.png"},{"id":56595463,"identity":"3ae6fd6f-0e51-405f-934a-14baa0207a69","added_by":"auto","created_at":"2024-05-16 10:20:03","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":729436,"visible":true,"origin":"","legend":"\u003cp\u003eSome selected snapshots of (a) \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e,\u003cstrong\u003e \u003c/strong\u003e(b) \u003cstrong\u003eBz\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e and (c) \u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e in MD trajectories. Along with MD simulation, all the three pillar-shape guest-loaded \u003cstrong\u003eEtP5Q1\u003c/strong\u003e collapsed and changed to the deformed configuration within \u003cstrong\u003eEtP5Q\u003c/strong\u003eβ, along with the guest release from the cavity and the unit cell.\u003c/p\u003e","description":"","filename":"image8.png","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/fbb96246fa9e13b3cf66b44f.png"},{"id":56595468,"identity":"f6b51e3c-2d1b-4b05-a7fe-a3557d76d76b","added_by":"auto","created_at":"2024-05-16 10:20:03","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":52870,"visible":true,"origin":"","legend":"\u003cp\u003eRecyclability of \u003cstrong\u003eEA\u003c/strong\u003e-regenerated\u003cstrong\u003e EtP5Q1\u003c/strong\u003eβ in the separation of \u003cstrong\u003ePy\u003c/strong\u003e/\u003cstrong\u003eTol\u003c/strong\u003e.\u003c/p\u003e","description":"","filename":"image9.png","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/ed301c0647676a033a4a8ed2.png"},{"id":61965996,"identity":"93f5bda2-6731-41f4-a2e8-bb166fe42357","added_by":"auto","created_at":"2024-08-07 15:33:46","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6401334,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/2fe0d52d-bd0e-48a7-a96d-53936c214668.pdf"},{"id":56595460,"identity":"d0789402-0421-4b52-bac9-2a3fd7dc2b3d","added_by":"auto","created_at":"2024-05-16 10:20:03","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":1719626,"visible":true,"origin":"","legend":"\u003cp\u003eSUPPLEMENTARY INFORMATION\u003c/p\u003e","description":"","filename":"SIsqueezetriggeredrelease.docx","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/bf329c49367ff033978fde6d.docx"},{"id":56595459,"identity":"234fa656-475d-476c-b1ce-bc8496bb8487","added_by":"auto","created_at":"2024-05-16 10:20:03","extension":"png","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":463619,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eScheme 1. \u003c/strong\u003eSchematic representation of (a) conventional guest desorption methods; (b) guest desorption from sponge–like macrocyclic crystals by molecular squeeze induced deformation.\u003c/p\u003e","description":"","filename":"Scheme1.png","url":"https://assets-eu.researchsquare.com/files/rs-4248303/v1/2b52c708b956c7c51b4cc8f8.png"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Molecular-Squeeze Triggers Guest Desorption from Sponge-Like Macrocyclic Crystals","fulltext":[{"header":"Introduction","content":"\u003cp\u003ePorous materials have long been recognized for their sponge\u0026ndash;like ability to adsorb guest molecules within their internal pores at the molecular level. This property has positioned task\u0026ndash;specific porous materials as valuable candidates for deployment in adsorptive separation processes, leveraging selective adsorption to achieve energy\u0026ndash;efficient and environmentally friendly separation in the chemical industry\u003csup\u003e1\u0026ndash;3\u003c/sup\u003e. An array of porous framework materials, including zeolites\u003csup\u003e4,5\u003c/sup\u003e, metal\u0026ndash;organic frameworks (MOFs)\u003csup\u003e6\u0026ndash;9\u003c/sup\u003e, covalent\u0026ndash;organic frameworks (COFs)\u003csup\u003e10\u0026ndash;12\u003c/sup\u003e, porous organic polymers (POPs)\u003csup\u003e13,14\u003c/sup\u003e, as well as porous molecular materials including porous organic cages (POCs)\u003csup\u003e15,16\u003c/sup\u003e and metal\u0026ndash;organic polyhedra (MOPs)\u003csup\u003e17,18\u003c/sup\u003e, have been extensively investigated as adsorbents in adsorptive separation applications. In the context of energy\u0026ndash;intensive adsorption separation processes, optimizing energy conservation hinges on the facile desorption or release of selectively\u0026ndash;trapped guests, coupled with the efficient regeneration and recyclability of the adsorbents. Traditional desorption processes for porous materials involve inert gas or vacuum pump usage, often combined with heating treatment, known as temperature\u0026ndash;swing adsorption (TSA) and pressure\u0026ndash;swing adsorption (PSA)\u003csup\u003e19\u0026ndash;23\u003c/sup\u003e. However, the substantial heat cost incurred due to either the high binding energy between the adsorbent and the guest or the high boiling point of the guest, resulting in elevated energy expenses that can be comparable to those associated with traditional distillation.\u003c/p\u003e\n\u003cp\u003eBeyond conventional porous materials, we recently discovered a novel class of adsorbents based on macrocyclic crystals, which are termed as nonporous adaptive crystals (NACs) in terms of their unique properties\u003csup\u003e24\u0026ndash;31\u003c/sup\u003e. These materials can function as sponges to adsorb guests in the solid\u0026ndash;vapor phase. Triggered by guest vapors, these nonporous crystalline materials undergo a structural transformation, creating voids that are absent in their initial state to accommodate guest molecules. The adaptive property, combined with distinct host\u0026ndash;guest interactions, facilitates the adsorption and separation of various hydrocarbons\u003csup\u003e32\u0026ndash;43\u003c/sup\u003e. Despite achieving reversible adsorption and desorption within these materials, the release or desorption of trapped guests, along with material regeneration, remains energy\u0026ndash;intensive. Prolonged and relatively high\u0026ndash;temperature heating in a vacuum is essential for releasing guest molecules due to the strong binding between the guest and macrocycles, with hydrocarbons boasting high boiling points posing additional challenges for one\u0026ndash;step desorption. \u003c/p\u003e\n\u003cp\u003eIn addition to guest uptake capability, another notable characteristic of typical sponges is their exceptional mechanical performance, enabling adaptation to external forces\u003csup\u003e44\u003c/sup\u003e. Consequently, desorption typically occurs in sponge\u0026ndash;like soft adsorbents (e.g., sponges, towels, fabrics), where external forces such as squeezing, twisting, and screwing induce material deformation, compress voids, and ultimately release guests. However, the material squeeze method is challenging to apply to current adsorbents, including porous materials and NACs, the majority of which are hard solids in bulk and lack sufficient mechanical performance\u003csup\u003e45\u0026ndash;49\u003c/sup\u003e. For these materials, external forces (inert gas, heating, vacuum) are often employed to interact with guests, triggering guest release through competitive intermolecular interactions (Scheme 1a). External forces applied to these host adsorbents for guest squeeze may prove ineffective or lead to material collapse.\u003c/p\u003e\n\u003cp\u003eDespite the lack of softness in bulk, NACs exhibit flexibility at the molecular level, as evidenced by their transformable crystal structures upon adsorption and desorption\u003csup\u003e31\u003c/sup\u003e. We thus anticipated that applying soft external forces at the molecular level to squeeze the adsorbents might facilitate energy\u0026ndash;efficient desorption. Herein, we present a molecular\u0026ndash;squeeze\u0026ndash;triggered guest release behavior in these sponge\u0026ndash;like macrocyclic crystals, a phenomenon that has been unprecedented previously. These macrocyclic crystals operate similarly to typical sponges, accommodating guest molecules within adaptively formed voids, resulting in enhanced separation performance for the toluene/pyridine azeotrope. In contrast to conventional desorption methods, specific vaporized molecules can induce guest release from the guest\u0026ndash;loaded crystals without penetrating the pores or voids. Instead, these vaporized molecules serve as external forces directly applied to the adsorbents, squeezing the crystals to close the voids and release the guest molecules (Scheme 1b). A combination of experimental techniques and molecular simulations unequivocally reveals the mechanism underlying the guest release process, emphasizing the significance of interactions between the vapor and the crystals. The fundamental principle is that these crystals tend to form the most thermodynamically stable, guest\u0026ndash;free structures in the presence of these vapors. Compared to previous guest release methods\u003csup\u003e22\u003c/sup\u003e\u003csup\u003e\u0026ndash;\u003c/sup\u003e\u003csup\u003e23\u003c/sup\u003e, this approach operates under mild conditions, ensuring high recyclability of the materials and consequently reducing both cost and energy consumption.\u003c/p\u003e"},{"header":"Results and Discussion","content":"\u003cp\u003e\u003cstrong\u003eSynthesis, Characterizations and Phase Transitions of Desolvated pillar\u003c/strong\u003e[\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e]\u003cstrong\u003earene\u003c/strong\u003e[\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e]\u003cstrong\u003equinone (EtP5Q1) Crystals.\u003c/strong\u003e The sponge\u0026ndash;like macrocyclic crystals are composed of pure pillar[\u003cspan class=\"CitationRef\"\u003e5\u003c/span\u003e]arene[\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e]quinone (\u003cstrong\u003eEtP5Q1\u003c/strong\u003e) molecules (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ea). \u003cstrong\u003eEtP5Q1\u003c/strong\u003e was firstly synthesized as brownish red powders by partial oxidation of perethylated pillar[\u003cspan class=\"CitationRef\"\u003e6\u003c/span\u003e]arene\u003csup\u003e25\u003c/sup\u003e. Heating the as\u0026ndash;synthesized powders overnight at 80\u0026deg;C in vacuum afforded a desolvated sample, as confirmed by \u003csup\u003e1\u003c/sup\u003eH NMR and thermogravimetric analysis (TGA) data (Supplementary Figs. S1 and S2). Powder X\u0026ndash;ray diffraction (PXRD) experiments showed its high crystallinity (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003eb and S3, referred to as \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e). Interestingly, recrystallization of the as\u0026ndash;synthesized \u003cstrong\u003eEtP5Q1\u003c/strong\u003e in ethyl acetate (\u003cstrong\u003eEA\u003c/strong\u003e) followed by a similar desolvation procedure afforded a new desolvated sample (Supplementary Figs. S4 and S5), which was demonstrated by PXRD to be a different polymorph of the material (referred to as \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e, Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003eb and S6). It is worth mentioning that polymorphism is common for molecular crystals but relatively rare for pillararene crystals\u003csup\u003e32\u0026ndash;43\u003c/sup\u003e. N\u003csub\u003e2\u003c/sub\u003e adsorption experiments showed that both \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e had very low Brunauer\u0026ndash;Emmett\u0026ndash;Teller (BET) surface area, similar to the nonporous nature of other pillararene crystals (Supplementary Figs. S7 and S8).\u003c/p\u003e\n\u003cp\u003eTo get deeper understanding of the two polymorphs, attempts were made to obtain their single crystal structures. After several trials, single crystals of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e were successfully obtained using vapor diffusion of cyclohexane (\u003cstrong\u003eCH\u003c/strong\u003e) into a chloroform solution. These crystals were further characterized using single crystal X\u0026ndash;ray diffraction (SC\u0026ndash;XRD) and are referred to as \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e. The structure of \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e adopts a \u003cem\u003eCc\u003c/em\u003e space group. In this structure, one \u003cstrong\u003eCH\u003c/strong\u003e molecule is situated in the hexagonal cavity center of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e, forming a 1:1 host\u0026ndash;guest complex. The stabilization of this complex is achieved through multiple CH\u0026middot;\u0026middot;\u0026middot;\u0026pi; interactions (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ec). The packing mode reveals that no interconnected channels are formed within the structure; instead, a staggered packing arrangement is observed (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ec, right). It is noteworthy that direct desolvation of a \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e single crystal resulted in its destruction into crystalline powders. This challenging outcome made it difficult to elucidate the structure of desolvated \u003cstrong\u003eEtP5Q1\u003c/strong\u003e through single crystal X\u0026ndash;ray diffraction (SC\u0026ndash;XRD). However, the PXRD patterns between \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and the desolvated \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e were almost identical, implying that they are the same phase (Supplementary Fig. S9). Meanwhile, compared with the PXRD pattern simulated from \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, the pattern of \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e remains almost unchanged with an exception that the diffraction peaks appear at slightly lower scattering angles (Supplementary Fig. S9). This is a typical phenomenon that the crystal lattice undergoes a slight expansion without changing the unit cell parameters, which on the other hand confirms the structural similarity between \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ee).\u003c/p\u003e\n\u003cp\u003eLuckily, single crystals of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e were also obtained by slow evaporation of an \u003cstrong\u003eEA\u003c/strong\u003e solution. As characterized by SC\u0026ndash;XRD, the crystal structure has \u003cem\u003eP\u003c/em\u003e\u0026ndash;1 space group. Different from \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, no \u003cstrong\u003eEA\u003c/strong\u003e molecules can be found within the structure, indicating a desolvated phase (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ed). \u003cstrong\u003eEtP5Q1\u003c/strong\u003e molecules adopt a densely\u0026ndash;packing mode, where one of the \u003cem\u003ep\u003c/em\u003e\u0026ndash;diethoxybenzene subunits rotates along the methylene axis into the cavity and is further stabilized by intramolecular CH\u0026middot;\u0026middot;\u0026middot;\u0026pi; interaction. \u003cstrong\u003eEtP5Q1\u003c/strong\u003e molecules are thus deformed with dense packing. The PXRD pattern simulated from the single crystal structure shows a good agreement with the experimental one of \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e (Supplementary Fig. S10), confirming that they are the same phase. This also indicates that recrystallization of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e from \u003cstrong\u003eEA\u003c/strong\u003e could afford \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e without further desolvation.\u003c/p\u003e\n\u003cp\u003eThe phase transition between the two polymorphs were then explored. Our previous studies show that pillararene crystals can act as adsorbents to adsorb vaporized guests along with crystal structure transitions\u003csup\u003e24\u003c/sup\u003e. We first exposed \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e to \u003cstrong\u003eCH\u003c/strong\u003e vapor and observed that adsorption of \u003cstrong\u003eCH\u003c/strong\u003e as well as crystal lattice shrinkage occurred (Figs.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ee, S11 and S12). However, when \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e crystals were exposed to \u003cstrong\u003eCH\u003c/strong\u003e vapor, neither \u003cstrong\u003eCH\u003c/strong\u003e adsorption nor crystal structure transition occurred, implying that the structure transition from \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e to \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e cannot be achieved (Figs.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ee, S13 and S14). Interestingly, when \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e was exposed to \u003cstrong\u003eEA\u003c/strong\u003e vapor, the PXRD pattern as well as \u003csup\u003e1\u003c/sup\u003eH NMR spectrum showed a clear phase transition from \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e to \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e without the adsorption of \u003cstrong\u003eEA\u003c/strong\u003e (Figs.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003ee, S15 and S16), which is unprecedented previously. This behavior is similar to sponges where \u003cstrong\u003eEA\u003c/strong\u003e acts as external forces to trigger the material deformation at the molecular level.\u003c/p\u003e\n\u003cp\u003eIn the context of differential scanning calorimetry (DSC) analysis, the obtained curves revealed distinctive thermal behavior for \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e (Supplementary Fig. S17). Specifically, \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e exhibited two discernible endothermic peaks, occurring at 137\u0026deg;C and 165\u0026deg;C, respectively. In contrast, \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e displayed a singular endothermic peak at 165\u0026deg;C. This DSC data unequivocally establishes that the endothermic peak at 137\u0026deg;C in \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e corresponds to a phase transition, while the peaks at 165\u0026deg;C signify the melting points of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals. The presence of a single endothermic peak in \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e at the higher temperature suggests that it is the thermodynamically more stable polymorph than \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAdsorption and Separation Performance of the Two EtP5Q1 Polymorphs.\u003c/strong\u003e Given the observed phase transitions and the cavity size of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e, we conducted adsorption experiments with common cyclic hydrocarbons, including \u003cstrong\u003eCH\u003c/strong\u003e, benzene (\u003cstrong\u003eBz\u003c/strong\u003e), toluene (\u003cstrong\u003eTol\u003c/strong\u003e), and pyridine (\u003cstrong\u003ePy\u003c/strong\u003e), utilizing the two polymorphs of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e. The single\u0026ndash;component vapor sorption isotherms (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e) reveal that both polymorphs function as adsorbents to effectively adsorb all four hydrocarbons, albeit with variations in adsorption capacity and kinetics. Notably, for \u003cstrong\u003eBz\u003c/strong\u003e, the adsorption capacity and kinetics were similar in both \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003eb). In contrast, the adsorption amounts of the other three guests in \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e were nearly twice those in \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e, underscoring the pivotal role of crystalline phases in dictating the adsorption behavior of molecular crystals. It is crucial to highlight the presence of hysteresis loops in the desorption process, indicating a notable challenge in the release of adsorbed hydrocarbons. Even under reduced pressure, a certain amount of hydrocarbons remained trapped, indicating the high binding strength between \u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals and hydrocarbon guests. Consequently, the desorption process proves to be energy\u0026ndash;consuming, posing a potential limitation if these materials were to be applied as adsorbents in adsorptive separation processes.\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eH NMR and TGA further confirmed the adsorption and storage of these hydrocarbons in \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e. The uptake of \u003cstrong\u003eCH\u003c/strong\u003e, \u003cstrong\u003ePy\u003c/strong\u003e, \u003cstrong\u003eBz\u003c/strong\u003e and \u003cstrong\u003eTol\u003c/strong\u003e can be calculated to be one molecule per \u003cstrong\u003eEtP5Q1\u003c/strong\u003e molecule (mole/\u003cstrong\u003eEtP5Q1\u003c/strong\u003e) in \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e, respectively. The uptake of \u003cstrong\u003ePy\u003c/strong\u003e and \u003cstrong\u003eBz\u003c/strong\u003e in \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e is similar to that of \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e while the uptake of \u003cstrong\u003eCH\u003c/strong\u003e and \u003cstrong\u003eTol\u003c/strong\u003e is negligible (Supplementary Figs. S18\u0026minus;S29). PXRD experiments were carried out to investigate the structures of \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e after uptake of the hydrocarbons. The PXRD patterns of \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e became different after adsorption of the four hydrocarbons (Supplementary Fig. S30), indicating the formation of new \u003cstrong\u003eEtP5Q1\u003c/strong\u003e structures. Similarly, the PXRD patterns of \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e after uptake of \u003cstrong\u003ePy\u003c/strong\u003e and \u003cstrong\u003eBz\u003c/strong\u003e were different from the original one, implying the formation of new \u003cstrong\u003eEtP5Q1\u003c/strong\u003e structures (Supplementary Fig. S31), while the patterns remained unchanged upon exposure to \u003cstrong\u003eCH\u003c/strong\u003e and \u003cstrong\u003eTol\u003c/strong\u003e (Supplementary Fig. S32). It is worth noting that the patterns of \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e after adsorption of \u003cstrong\u003ePy\u003c/strong\u003e or \u003cstrong\u003eBz\u003c/strong\u003e are almost the same with each other, respectively, meaning that two original phases switch to the same crystal structure after adsorption of the same guest (Supplementary Figs. S33 and S34).\u003c/p\u003e\n\u003cp\u003eTo reveal these new structures, hydrocarbon\u0026ndash;loaded single crystal structures of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e were obtained. In the crystal structure of \u003cstrong\u003eBz\u003c/strong\u003e\u0026ndash;loaded \u003cstrong\u003eEtP5Q1\u003c/strong\u003e (\u003cstrong\u003eBz\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003ea), one \u003cstrong\u003eBz\u003c/strong\u003e molecule was loaded inside the cavity center of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e with the other \u003cstrong\u003eBz\u003c/strong\u003e molecule trapped in the extrinsic space of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003ea, middle), forming a 2:1 complex crystal. Similarly, in the analogous \u003cstrong\u003eTol\u003c/strong\u003e\u0026ndash;loaded crystal structure of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e (\u003cstrong\u003eTol\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003eb), a \u003cstrong\u003eTol\u003c/strong\u003e molecule is located in the center of the \u003cstrong\u003eEtP5Q1\u003c/strong\u003e cavity, while the other one is located in the extrinsic space of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e molecules (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003eb), also forming a 2:1 complex crystal. In \u003cstrong\u003ePy\u003c/strong\u003e\u0026ndash;loaded \u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystal structure (\u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003ec), all three \u003cstrong\u003ePy\u003c/strong\u003e molecules are located in the cavity of \u003cstrong\u003eEtP5Q1\u003c/strong\u003e, forming a 1:3 host\u0026ndash;guest complex (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003ec, middle), which is rarely observed in pillararene\u0026ndash;based host\u0026ndash;guest systems\u003csup\u003e26\u003c/sup\u003e. The window\u0026ndash;to\u0026ndash;window packing mode of hexagonal \u003cstrong\u003eEtP5Q1\u003c/strong\u003e molecules in \u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e contributes to the formation of honeycomb\u0026ndash;like infinite 1D channels (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003ec, right).\u003c/p\u003e\n\u003cp\u003eWe proceeded to investigate whether \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e could effectively discriminate between mixtures of \u003cstrong\u003eCH\u003c/strong\u003e and \u003cstrong\u003eBz\u003c/strong\u003e or mixtures of \u003cstrong\u003eTol\u003c/strong\u003e and \u003cstrong\u003ePy\u003c/strong\u003e, both of which hold significant relevance in the chemical industry. To assess selectivity, time\u0026ndash;dependent solid\u0026ndash;vapor sorption experiments were conducted using a 1:1 volumetric ratio of \u003cstrong\u003eBz\u003c/strong\u003e:\u003cstrong\u003eCH\u003c/strong\u003e or \u003cstrong\u003eTol\u003c/strong\u003e:\u003cstrong\u003ePy\u003c/strong\u003e. In the case of \u003cstrong\u003eCH\u003c/strong\u003e/\u003cstrong\u003eBz\u003c/strong\u003e separation, neither \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e nor \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e exhibited selective uptake of \u003cstrong\u003eBz\u003c/strong\u003e or \u003cstrong\u003eCH\u003c/strong\u003e, as evidenced by NMR analyses (Supplementary Figs. S35 and S36). However, in the \u003cstrong\u003eTol\u003c/strong\u003e/\u003cstrong\u003ePy\u003c/strong\u003e separation scenario, both \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e demonstrated remarkable selectivity towards \u003cstrong\u003ePy\u003c/strong\u003e (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003ea and \u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003eb). The sole difference lay in sorption kinetics, with the uptake rate of \u003cstrong\u003ePy\u003c/strong\u003e in \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e being slightly faster than that in \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e. Gas chromatography (GC) experiments indicated that the percentages of \u003cstrong\u003ePy\u003c/strong\u003e adsorbed in \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e were 99.7% and 99.5%, respectively (Supplementary Figs. S37 and S38). The PXRD patterns of both \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e after adsorption of the \u003cstrong\u003eTol\u003c/strong\u003e/\u003cstrong\u003ePy\u003c/strong\u003e mixture align with that simulated from \u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e (Supplementary Fig. S33), underscoring structural transformations from the original phases to \u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, respectively (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e4\u003c/span\u003ec). This attests to the potential of \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e as promising candidates for the selective separation of \u003cstrong\u003eTol\u003c/strong\u003e/\u003cstrong\u003ePy\u003c/strong\u003e mixtures, offering valuable applications in chemical processes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eVapor\u0026ndash;Triggered Guest Release.\u003c/strong\u003e The ease of guest release is a critical consideration in practical adsorptive separation processes, as this step typically accounts for the majority of energy consumption in the overall process. However, the formidable binding between the guest and \u003cstrong\u003eEtP5Q1\u003c/strong\u003e presents a challenge in releasing adsorbates from \u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals. This challenge is evident in the vapor desorption isotherm, where a substantial amount of guests cannot be released from the crystals even under reduced pressure (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). This difficulty is not unique to \u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals but is a common issue encountered with other crystalline adsorbents based on pillararenes and macrocycles\u003csup\u003e24\u003c/sup\u003e. Previous studies have indicated that only prolonged heating at elevated temperatures in a vacuum environment could effectively release adsorbates\u003csup\u003e27\u003c/sup\u003e. In the case of \u003cstrong\u003ePy\u003c/strong\u003e, for instance, only overnight heating at an elevated temperature in a vacuum could achieve desorption. This process is undeniably energy\u0026ndash;intensive and time\u0026ndash;consuming, presenting a significant barrier to the practical application of these materials in real production scenarios. Additionally, the challenging conditions make the collection of the desorbed guest extremely difficult. Therefore, there is a pressing need to develop new and more efficient desorption methods for these materials to enhance their practical utility in industrial applications.\u003c/p\u003e\n\u003cp\u003eThe intriguing phase transition observed from \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e to \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e triggered by \u003cstrong\u003eEA\u003c/strong\u003e vapor has captured our attention, as \u003cstrong\u003eEA\u003c/strong\u003e essentially functions as an external force to induce molecular\u0026ndash;level deformation inside the crystals. This raises a compelling question: could \u003cstrong\u003eEA\u003c/strong\u003e trigger the phase transition of guest\u0026ndash;loaded \u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals to \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e, potentially leading to the desorption of guests through structural deformation? Given the structural similarity between \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e and \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, we conducted an initial experiment by exposing \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e to \u003cstrong\u003eEA\u003c/strong\u003e vapor at room temperature. Surprisingly, time\u0026ndash;dependent \u003csup\u003e1\u003c/sup\u003eH NMR spectra revealed a gradual decrease in the content of \u003cstrong\u003eCH\u003c/strong\u003e within \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, eventually disappearing entirely after 150 minutes (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003ea). Concurrently, \u003cem\u003eex situ\u003c/em\u003e PXRD patterns demonstrated a time\u0026ndash;dependent transformation process in the PXRD pattern of \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, ultimately converging to the same pattern as that of \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003eb). These findings collectively indicate that \u003cstrong\u003eEA\u003c/strong\u003e vapor has the ability to trigger the release of \u003cstrong\u003eCH\u003c/strong\u003e from \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e under ambient conditions, accompanied by the phase transition from \u003cstrong\u003eCH\u003c/strong\u003e\u0026ndash;loaded \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e to guest\u0026ndash;free \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e5\u003c/span\u003ec).\u003c/p\u003e\n\u003cp\u003eSubsequent experiments involving other guest\u0026ndash;loaded \u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals were conducted with the anticipation that the observed phenomenon with \u003cstrong\u003eCH\u003c/strong\u003e in \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e could be extended to different guests. Exposure to \u003cstrong\u003eEA\u003c/strong\u003e vapor at ambient conditions resulted in similar outcomes for \u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e and \u003cstrong\u003eBz\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e. Time\u0026ndash;dependent \u003csup\u003e1\u003c/sup\u003eH NMR spectra revealed a gradual decrease in the content of \u003cstrong\u003eBz\u003c/strong\u003e within \u003cstrong\u003eBz\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e and \u003cstrong\u003ePy\u003c/strong\u003e within \u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, respectively (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003ea and \u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003eb). The absence of these guest molecules within the crystals post\u0026ndash;exposure to \u003cstrong\u003eEA\u003c/strong\u003e vapor was also confirmed by \u003csup\u003e1\u003c/sup\u003eH NMR spectra and TGA curves (Supplementary Figs. S41\u0026minus;S45). Additionally, the PXRD patterns of these guest\u0026ndash;loaded crystals all transitioned to match that of \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e after exposure to \u003cstrong\u003eEA\u003c/strong\u003e vapor (Figs.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e6\u003c/span\u003ec, S40 and S43). These comprehensive characterizations collectively indicate that regardless of the nature of the guest molecules included in \u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals, \u003cstrong\u003eEA\u003c/strong\u003e vapor has the remarkable capability to trigger their release from the crystals without necessitating entry into the pores.\u003c/p\u003e\n\u003cp\u003eTo uncover the unconventional desorption mechanism, we systematically investigated a dozen molecules structurally similar to \u003cstrong\u003eEA\u003c/strong\u003e and explored their ability to induce guest release from \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e. Table \u003cspan class=\"InternalRef\"\u003eS1\u003c/span\u003e summarizes the results obtained from PXRD experiments, demonstrating the squeeze\u0026ndash;induced guest release properties of these molecules. Notably, molecules with similar or longer chain lengths and bearing ketone groups on the chain exhibited the same capacity as \u003cstrong\u003eEA\u003c/strong\u003e to trigger \u003cstrong\u003eCH\u003c/strong\u003e release, as evidenced by PXRD experiments (Supplementary Fig. S46). Diethyl ether, lacking ketone groups, was the sole exception among the molecules that can initiate \u003cstrong\u003eCH\u003c/strong\u003e release. Conversely, molecules with shorter chain lengths or lacking ketone groups were unable to induce guest release from \u003cstrong\u003eEtP5Q1\u003c/strong\u003e crystals. This observation implies that both the functional groups and chain length play crucial roles in conferring the molecule's ability to function as a squeeze force, triggering guest release from the crystalline structure.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGuest Release Mechanism.\u003c/strong\u003e To further understand how the vapor triggers the guest release along with the structural transition, we carried out binding/lattice energy calculations. As shown in Table S3 and S4, the calculated energy of \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e is lower than \u003cstrong\u003eEtP5Q1\u0026alpha;\u003c/strong\u003e, indicating that \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e is the thermodynamically more stable polymorph, which is consistent with the experimental result.\u003c/p\u003e\n\u003cp\u003eMolecular dynamics (MD) simulations also revealed the configuration transition from guest\u0026ndash;loaded \u003cstrong\u003eEtP5Q1\u003c/strong\u003e structures to \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e in \u003cstrong\u003eEA\u003c/strong\u003e atmosphere (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003e). For instance, in the case of \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e, the host\u0026ndash;guest intermolecular distance is gradually increased during MD simulations. And at about 10 ns, the backbone of pillar\u0026ndash;shape \u003cstrong\u003eEtP5Q1\u003c/strong\u003e collapsed and changed to the deformed configuration within \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e, along with \u003cstrong\u003eCH\u003c/strong\u003e release from the cavity as well as the unit cell, whereas \u003cstrong\u003eEA\u003c/strong\u003e molecules neither enter the cavity nor the crystal lattice in the whole simulation procedure. Instead, \u003cstrong\u003eEA\u003c/strong\u003e molecules function more likely as external force to squeeze and deform the hexagonal \u003cstrong\u003eEtP5Q1\u003c/strong\u003e and close the cavity in the end (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003ea). This behavior further confirms the guest release is triggered via molecular squeeze rather than competitive guest\u0026ndash;host or gust\u0026ndash;guest interactions. Meanwhile, the similar dynamics simulation results were also observed for \u003cstrong\u003eBz\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e2\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e and \u003cstrong\u003ePy\u003c/strong\u003e\u003csub\u003e\u003cstrong\u003e3\u003c/strong\u003e\u003c/sub\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e in the presence of \u003cstrong\u003eEA\u003c/strong\u003e vapor (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003eb and \u003cspan class=\"InternalRef\"\u003e7\u003c/span\u003ec), further confirming the universality of the molecular squeeze triggered guest release behavior in these sponge\u0026ndash;like crystals.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRecyclability of EA\u0026ndash;Regenerated EtP5Q1\u0026beta; Crystals.\u003c/strong\u003e For an adsorbent to be practically useful, it must exhibit consistent and reliable performance over multiple cycles without degradation. In a previous demonstration, we illustrated that the material could be reproduced through long\u0026ndash;term heating in a vacuum. However, this method is both energy and time\u0026ndash;consuming. An important question arises regarding whether the vapor\u0026ndash;regenerated \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e crystals can be recycled effectively in the separation process. Conducting repeated experiments in \u003cstrong\u003eTol\u003c/strong\u003e/\u003cstrong\u003ePy\u003c/strong\u003e separation, we found that the vapor\u0026ndash;regenerated \u003cstrong\u003eEtP5Q1\u0026beta;\u003c/strong\u003e crystals maintained their separation performance over at least five cycles without any loss in efficiency (Fig.\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e8\u003c/span\u003e). This highlights the potential of our method as a rapid and efficient route to achieve adsorbent recyclability, addressing a critical aspect for the practical application of these materials in adsorptive separation processes.\u003c/p\u003e\n\u003cp\u003eIn conclusion, a molecular\u0026ndash;squeeze triggered guest release behavior from sponge\u0026ndash;like macrocyclic crystals was reported for the first time. The material functions akin to a typical sponge by encapsulating guest molecules within adaptively formed voids, serving as adsorbents for separating toluene and pyridine. Interestingly, vaporized \u003cstrong\u003eEA\u003c/strong\u003e molecules could trigger the guest release from the sponge without entering the pores or voids of the adsorbent to replace the guest. Instead, they work as external forces applied directly onto the adsorbents themselves, squeezing the materials to close the voids and release the guest molecules. Through various experimental techniques and molecular dynamics simulations, the mechanism behind the molecular\u0026ndash;squeeze guest release process was elucidated. The regenerated material from vapor\u0026ndash;induced release can be recycled multiple times without compromising separation performance. Compared to conventional guest release methods, this approach operates under mild conditions, leading to cost and energy savings. This discovery not only provides inspiration to develop new desorption process and mechanism, but also suggests the possibility of utilizing external forces to squeeze other soft crystalline adsorbents such as flexible MOFs and soft porous crystals for energy\u0026ndash;efficient desorption process.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data generated in this study are provided in this article and Supplementary Information file. Additional data are available from the corresponding author upon request. Crystallographic data for \u003cstrong\u003eTol\u003csub\u003e2\u003c/sub\u003e@EtP5Q1\u003c/strong\u003e, \u003cstrong\u003eEtP5Q1\u003c/strong\u003e\u003cstrong\u003eβ\u003c/strong\u003e, \u003cstrong\u003ePy\u003csub\u003e3\u003c/sub\u003e@EtP5Q1\u003c/strong\u003e, \u003cstrong\u003eCH\u003c/strong\u003e@\u003cstrong\u003eEtP5Q1\u003c/strong\u003e and \u003cstrong\u003eBz\u003csub\u003e2\u003c/sub\u003e@EtP5Q1\u003c/strong\u003e have been deposited at the Cambridge Crystallographic Data Centre (www.ccdc.cam.ac.uk/data_request/cif) and could be downloaded free of charge by the deposition number of 2339419, 2339420, 2339421, 2339422 and 2339423, respectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Natural Science Foundation of China (22301131 and 22033004), the Natural Science Foundation of Jiangsu Province (BK20220781), the Fundamental Research Funds for the Central Universities (020514380285), and the State Key Laboratory of Coordination Chemistry (119001).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eL.Z. and K.J. conceived the project and designed the experiments. L.Z. and Y.S. conducted the synthesis, adsorption and separation experiments. L.N.Z. performed vapor\u0026ndash;triggered guest release experiments and analyzed the data. L.F.Z. and J.M. performed the theoretical calculation and analyzed data. L.Z.N, J.M., K.J. co-wrote the paper. L.N.Z., L.F.Z., J.H., H.N., J.M. and K.J. discussed the results and commented on the manuscript.\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\n\u003cp\u003e\u003cstrong\u003eAdditional information\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing financial interests. Supplementary information accompanies this paper at https://www.nature.com/natchemeng. Reprints and permission information is available online at http://www.nature.com/reprints. Correspondence and requests for materials should be addressed to K.J.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eSholl, D. S. \u0026amp; Lively, R. P. Seven Chemical Separations to Change the World. \u003cem\u003eNature \u003c/em\u003e\u003cstrong\u003e532\u003c/strong\u003e, 435\u0026ndash;437 (2016).\u003c/li\u003e\n\u003cli\u003eWu, Y. \u0026amp; Weckhuysen, B. M. Separation and Purification of Hydrocarbons with Porous Materials. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e60\u003c/strong\u003e, 18930\u0026ndash;18949 (2021).\u003c/li\u003e\n\u003cli\u003eFarmahini, A. H., Krishnamurthy, S., Friedrich, D., Brandani, S. \u0026amp; Sarkisov, L. Performance\u0026ndash;Based Screening of Porous Materials for Carbon Capture. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e121\u003c/strong\u003e, 10666\u0026ndash;10741 (2021).\u003c/li\u003e\n\u003cli\u003eMa, X., Kumar, P., Daoutidis, P., Mkhoyan, K. A. \u0026amp; Tsapatsis, M. Zeolitic imidazolate framework membranes made by ligand\u0026ndash;induced permselectivation. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e361\u003c/strong\u003e, 1008\u0026ndash;1011 (2018).\u003c/li\u003e\n\u003cli\u003eP\u0026eacute;rez-Botella, E., Valencia, S. \u0026amp; Rey, F. Zeolites in Adsorption Processes: State of the Art and Future Prospects. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e122\u003c/strong\u003e, 17647\u0026ndash;17695 (2022).\u003c/li\u003e\n\u003cli\u003eZhao, X., Wang, Y., Li, D. S., Bu, X. \u0026amp; Feng, P. Metal\u0026ndash;Organic Frameworks for Separation. \u003cem\u003eAdv. Mater.\u003c/em\u003e \u003cstrong\u003e30\u003c/strong\u003e, 1705189 (2018).\u003c/li\u003e\n\u003cli\u003eCui, W. G., Hu, T. L. \u0026amp; Bu, X. H. Metal\u0026ndash;Organic Framework Materials for the Separation and Purification of Light Hydrocarbons. \u003cem\u003eAdv. Mater.\u003c/em\u003e \u003cstrong\u003e32\u003c/strong\u003e, 1806445 (2019).\u003c/li\u003e\n\u003cli\u003eQian, Q., Asinger, P. A., Lee, M. J., Chi, W. S. \u0026amp; Smith, Z. P. MOF\u0026ndash;Based Membranes for Gas Separations. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e120\u003c/strong\u003e, 8161\u0026ndash;8266 (2020).\u003c/li\u003e\n\u003cli\u003eWang, H., Liu, Y. \u0026amp; Li, J. Designer Metal\u0026ndash;Organic Frameworks for Size\u0026ndash;Exclusion\u0026ndash;Based Hydrocarbon Separations: Progress and Challenges. \u003cem\u003eAdv. Mater.\u003c/em\u003e \u003cstrong\u003e32\u003c/strong\u003e, 2002603 (2020).\u003c/li\u003e\n\u003cli\u003eWang, Z., Zhang, S., Chen, Y., Zhang, Z. \u0026amp; Ma, S. Covalent organic frameworks for separation applications. \u003cem\u003eChem. Soc. Rev.\u003c/em\u003e \u003cstrong\u003e49\u003c/strong\u003e, 708\u0026ndash;735 (2020).\u003c/li\u003e\n\u003cli\u003eGeng, K.\u003cem\u003e et al.\u003c/em\u003e Covalent Organic Frameworks: Design, Synthesis, and Functions. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e120\u003c/strong\u003e, 8814\u0026ndash;8933 (2020).\u003c/li\u003e\n\u003cli\u003eYuan, S., Li, X., Zhang, G., Van Puyvelde, P. \u0026amp; Van der Bruggen, B. Covalent organic frameworks for membrane separation. \u003cem\u003eChem. Soc. Rev.\u003c/em\u003e \u003cstrong\u003e48\u003c/strong\u003e, 2665\u0026ndash;2681 (2019).\u003c/li\u003e\n\u003cli\u003eSong, K. S., Fritz, P. W. \u0026amp; Coskun, A. Porous organic polymers for CO\u003csub\u003e2\u003c/sub\u003e\u003csub\u003e \u003c/sub\u003ecapture, separation and conversion. \u003cem\u003eChem. Soc. Rev.\u003c/em\u003e \u003cstrong\u003e51\u003c/strong\u003e, 9831\u0026ndash;9852 (2022).\u003c/li\u003e\n\u003cli\u003eWu, J., Xu, F., Fu, R. \u0026amp; Wu, D. Porous Polymers as Multifunctional Material Platforms toward Task-Specific Applications. \u003cem\u003eAdv. Mater.\u003c/em\u003e \u003cstrong\u003e31\u003c/strong\u003e, 1802922 (2018).\u003c/li\u003e\n\u003cli\u003eYang, X., Ullah, Z., Stoddart, J. F. \u0026amp; Yavuz, C. T. Porous Organic Cages. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e123\u003c/strong\u003e, 4602\u0026ndash;4634 (2023).\u003c/li\u003e\n\u003cli\u003eLiu, M., Zhang, L., Ceriotti, M., Hirscher, M. \u0026amp; Cooper, A. I. Barely porous organic cages for hydrogen isotope separation. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e366\u003c/strong\u003e, 613\u0026ndash;620 (2019).\u003c/li\u003e\n\u003cli\u003eGosselin, A. J., Rowland, C. A. \u0026amp; Bloch, E. D. Permanently Microporous Metal\u0026ndash;Organic Polyhedra. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e120\u003c/strong\u003e, 8987\u0026ndash;9014 (2020).\u003c/li\u003e\n\u003cli\u003eGuo, X., Xu, S., Huang, H. \u0026amp; Zhong, C. Metal\u0026ndash;organic polyhedron membranes for molecular separation. \u003cem\u003eJ. Membr. Sci.\u003c/em\u003e \u003cstrong\u003e632\u003c/strong\u003e, 119354 (2021).\u003c/li\u003e\n\u003cli\u003eRen, T., Patel, M. \u0026amp; Blok, K. Olefins from conventional and heavy feedstocks: Energy use in steam cracking and alternative processes. \u003cem\u003eEnergy\u003c/em\u003e \u003cstrong\u003e31\u003c/strong\u003e, 425\u0026ndash;451 (2006).\u003c/li\u003e\n\u003cli\u003eWang, S.-M., Shivanna, M., Space, B., Kitagawa, S. \u0026amp; Zaworotko, M. J. Ethane/Ethylene Separations in Flexible Diamondoid Coordination Networks via an Ethane\u0026ndash;Induced Gate\u0026ndash;Opening Mechanism. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e146\u003c/strong\u003e, 4153\u0026ndash;4161 (2024).\u003c/li\u003e\n\u003cli\u003eGu, C., Hosono, N., Kusaka, S., Sakaki, S. \u0026amp; Kitagawa, S. Design and control of gas diffusion process in a nanoporous soft crystal. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e363\u003c/strong\u003e, 387\u0026ndash;391 (2019).\u003c/li\u003e\n\u003cli\u003eLin, Y., Yu, L., Xia, Q., Thonhauser, T. \u0026amp; Li, J. Temperature-Programmed Separation of Hexane Isomers by a Porous Calcium Chloranilate Metal-Organic Framework. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e61\u003c/strong\u003e, e202214060 (2022).\u003c/li\u003e\n\u003cli\u003eXia, W., Yang, Y., Yang, Q., Ren, Q. \u0026amp; Bao, Z. Temperature\u0026ndash;dependent molecular sieving of fluorinated propane/propylene mixtures by a flexible\u0026ndash;robust metal\u0026ndash;organic framework. \u003cem\u003eSci. Adv.\u003c/em\u003e \u003cstrong\u003e10\u003c/strong\u003e, eadj6473 (2024).\u003c/li\u003e\n\u003cli\u003eJie, K., Zhou, Y., Li, E. \u0026amp; Huang, F. Nonporous Adaptive Crystals of Pillararenes. \u003cem\u003eAcc. Chem. Res.\u003c/em\u003e \u003cstrong\u003e51\u003c/strong\u003e, 2064\u0026ndash;2072 (2018).\u003c/li\u003e\n\u003cli\u003eOgoshi, T., Yamagishi, T.-a. \u0026amp; Nakamoto, Y. Pillar\u0026ndash;Shaped Macrocyclic Hosts Pillar[n]arenes: New Key Players for Supramolecular Chemistry. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cstrong\u003e116\u003c/strong\u003e, 7937\u0026ndash;8002 (2016).\u003c/li\u003e\n\u003cli\u003eWu, J. R. \u0026amp; Yang, Y. W. Synthetic Macrocycle-Based Nonporous Adaptive Crystals for Molecular Separation. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e60\u003c/strong\u003e, 1690-1701 (2020).\u003c/li\u003e\n\u003cli\u003eJie, K., Liu, M., Chen, L., Huang, F. \u0026amp; Cooper, A. I. Styrene Purification by Guest\u0026ndash;Induced Restructuring of Pillar[6]arene. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e139\u003c/strong\u003e, 2908\u0026ndash;2911 (2017).\u003c/li\u003e\n\u003cli\u003eAdachi, K., Fa, S., Akine, S. \u0026amp; Ogoshi, T. Adaptive Planar Chirality of Pillar[5]arenes Invertible by \u003cem\u003en\u003c/em\u003e\u0026ndash;Alkane Lengths. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e145\u003c/strong\u003e, 8114\u0026ndash;8121 (2023).\u003c/li\u003e\n\u003cli\u003eOgoshi, T., Saito, K., Kakuta, T. \u0026amp; Yamagishi, T. a. Separation of Linear and Branched Alkanes Using Host\u0026ndash;Guest Complexation of Cyclic and Branched Alkane Vapors by Crystal State Pillar[6]arene. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e57\u003c/strong\u003e, 1592\u0026ndash;1595 (2018).\u003c/li\u003e\n\u003cli\u003eJie, K., Zhou, Y., Li, E., Zhao, R. \u0026amp; Huang, F. Separation of Aromatics/Cyclic Aliphatics by Nonporous Adaptive Pillararene Crystals. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e57\u003c/strong\u003e, 12845\u0026ndash;12849 (2018).\u003c/li\u003e\n\u003cli\u003eJie, K., Liu, M., Day, G. M., Huang, F. \u0026amp; Cooper, A. I. Near\u0026ndash;Ideal Xylene Selectivity in Adaptive Molecular Pillar[n]arene Crystals. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e140\u003c/strong\u003e, 6921\u0026ndash;6930 (2018).\u003c/li\u003e\n\u003cli\u003eZhu, H., Chen, L., Li, H., Stoddart, J. F. \u0026amp; Huang, F. Applications of macrocycle\u0026ndash;based solid\u0026ndash;state host\u0026ndash;guest chemistry. \u003cem\u003eNat. Rev. Chem.\u003c/em\u003e \u003cstrong\u003e7\u003c/strong\u003e, 768\u0026ndash;782 (2023).\u003c/li\u003e\n\u003cli\u003eLi, Q., Zhu, H. \u0026amp; Huang, F. Pillararene\u0026ndash;Based Supramolecular Functional Materials. \u003cem\u003eTrends Chem.\u003c/em\u003e \u003cstrong\u003e2\u003c/strong\u003e, 850\u0026ndash;864 (2020).\u003c/li\u003e\n\u003cli\u003eOgoshi, T. Pillar\u0026ndash;Shaped Macrocyclic Hosts Pillar[\u003cem\u003en\u003c/em\u003e]arenes: From Simple Receptors to Supramolecular Assemblies. \u003cem\u003eAsiaChem Magazine\u003c/em\u003e \u003cstrong\u003e2\u003c/strong\u003e, 72\u0026ndash;79 (2021).\u003c/li\u003e\n\u003cli\u003eZeng, F., Cheng, L., Zhang, W.-J., Tang, L.-L. \u0026amp; Wang, X.-F. Phenanthrene[2]arene: synthesis and application as nonporous adaptive crystals in the separation of benzene from cyclohexane. \u003cem\u003eOrg. Chem. Front.\u003c/em\u003e \u003cstrong\u003e9\u003c/strong\u003e, 3307\u0026ndash;3311 (2022).\u003c/li\u003e\n\u003cli\u003eLi, M., Shao, L., Khashab, N. M., Hua, B. \u0026amp; Huang, F. \u003cem\u003eCis\u003c/em\u003e\u0026ndash;\u003cem\u003eTrans\u003c/em\u003e and Length\u0026ndash;Selective Molecular Discrimination of Halogenated Organic Compounds by a Crystalline Hybrid Macrocyclic Arene. \u003cem\u003eACS Appl. Mater. Interfaces\u003c/em\u003e \u003cstrong\u003e16\u003c/strong\u003e, 6614\u0026ndash;6622 (2024).\u003c/li\u003e\n\u003cli\u003eDing, Y., Alimi, L. O., Jacquemin, J., Huang, F. \u0026amp; Khashab, N. M. Selective adsorptive separation of cyclohexane over benzene using thienothiophene cages. \u003cem\u003eChem. Sci.\u003c/em\u003e \u003cstrong\u003e12\u003c/strong\u003e, 5315\u0026ndash;5318 (2021).\u003c/li\u003e\n\u003cli\u003eZhao, Y., Xiao, H., Tung, C.-H., Wu, L.-Z. \u0026amp; Cong, H. Adsorptive separation of cyclohexanol and cyclohexanone by nonporous adaptive crystals of RhombicArene. \u003cem\u003eChem. Sci.\u003c/em\u003e \u003cstrong\u003e12\u003c/strong\u003e, 15528\u0026ndash;15532 (2021).\u003c/li\u003e\n\u003cli\u003eYang, W., Samanta, K., Zuilhof, H. \u0026amp; Sue, A. C. H. Tiara[5]arenes: Synthesis, Solid‐State Conformational Studies, Host-Guest Properties, and Application as Nonporous Adaptive Crystals. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e59\u003c/strong\u003e, 3994-3999 (2020).\u003c/li\u003e\n\u003cli\u003eWu, J.-R. \u0026amp; Yang, Y.-W. Geminiarene: Molecular Scale Dual Selectivity for Chlorobenzene and Chlorocyclohexane Fractionation. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e141\u003c/strong\u003e, 12280\u0026ndash;12287 (2019).\u003c/li\u003e\n\u003cli\u003eWu, J., Li, B. \u0026amp; Yang, Y. Separation of Bromoalkanes Isomers by Nonporous Adaptive Crystals of Leaning Pillar[6]arene. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e59\u003c/strong\u003e, 2251\u0026ndash;2255 (2019).\u003c/li\u003e\n\u003cli\u003eWang, Y., Xu, K., Fang J. \u0026amp; Li. C. Efficient Separation of \u003cem\u003ecis\u003c/em\u003e- and \u003cem\u003etrans\u003c/em\u003e-1,2-Dichloroethene Isomers by Adaptive Biphen[3]arene Crystals. \u003cem\u003eAngew. Chem. Int. Ed.\u003c/em\u003e \u003cstrong\u003e58\u003c/strong\u003e, 10281-10284 (2019).\u003c/li\u003e\n\u003cli\u003eLuo, D., Tian, J., Sessler, J. L. \u0026amp; Chi, X. Nonporous Adaptive Calix[4]pyrrole Crystals for Polar Compound Separations. \u003cem\u003eJ. Am. Chem. Soc.\u003c/em\u003e \u003cstrong\u003e143\u003c/strong\u003e, 18849\u0026ndash;18853 (2021).\u003c/li\u003e\n\u003cli\u003eJiang, Y., Tan, P., Liu, X.-Q. \u0026amp; Sun, L.-B. Breathing Metal\u0026ndash;Organic Polyhedra Controlled by Light for Carbon Dioxide Capture and Liberation. \u003cem\u003eCCS Chem.\u003c/em\u003e \u003cstrong\u003e3\u003c/strong\u003e, 1659\u0026ndash;1668 (2021).\u003c/li\u003e\n\u003cli\u003eLin, R.-B., Xiang, S., Zhou, W. \u0026amp; Chen, B. Microporous Metal\u0026ndash;Organic Framework Materials for Gas Separation. \u003cem\u003eChem\u003c/em\u003e \u003cstrong\u003e6\u003c/strong\u003e, 337\u0026ndash;363 (2020).\u003c/li\u003e\n\u003cli\u003eLin, R.-B., He, Y., Wang, H., Zhou, W. \u0026amp; Chen, B. Multifunctional porous hydrogen\u0026ndash;bonded organic framework materials. \u003cem\u003eChem. Soc. Rev.\u003c/em\u003e \u003cstrong\u003e48\u003c/strong\u003e, 1362\u0026ndash;1389 (2019).\u003c/li\u003e\n\u003cli\u003eZhang, D., Ronson, T. K., Zou, Y.\u0026ndash;Q. \u0026amp; Nitschke, J. R. Metal\u0026ndash;organic cages for molecular separations. \u003cem\u003eNat. Rev. Chem.\u003c/em\u003e \u003cstrong\u003e5\u003c/strong\u003e, 168\u0026ndash;182 (2021).\u003c/li\u003e\n\u003cli\u003eHerm, Z. R., Wiers, B. M., Mason, J. A., Krishna, R. \u0026amp; Long, J. R. Separation of Hexane Isomers in a Metal\u0026ndash;Organic Framework with Triangular Channels. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e340\u003c/strong\u003e, 960\u0026ndash;964 (2013).\u003c/li\u003e\n\u003cli\u003eLi, L., Lin, R.-B., Li, J., Zhou, W. \u0026amp; Chen, B. Ethane/ethylene separation in a metal\u0026ndash;organic framework with iron\u0026ndash;peroxo sites. \u003cem\u003eScience\u003c/em\u003e \u003cstrong\u003e362\u003c/strong\u003e, 443\u0026ndash;446 (2018).\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Scheme","content":"\u003cp\u003eScheme 1 is available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-4248303/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4248303/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eDesorption in conventional porous sorbents often employ external forces including inert gas blowing, heating, vacuum treatment to trigger guest release through competitive intermolecular interactions. We here report an unprecedented molecular–squeeze triggered guest release behavior from sponge–like macrocyclic crystals. The crystals function as typical sponge to include guest molecules within their microscopic voids that are adaptively formed, thus acting as adsorbents for toluene/pyridine separations. Intriguingly, vaporized ethyl acetate molecules trigger the guest release from the crystals without entering the pores or voids of the adsorbent to replace the guest. Instead, they work as external forces applied directly onto the crystals themselves, squeezing the materials to close the voids and release the guest molecules. Various experimental techniques as well as molecular dynamics simulations reveal the mechanism of the molecular–squeeze induced guest release procedure. The vapor–regenerated crystals can be recycled multiple times without the loss of separation performance. Compared with conventional guest release procedure, this method is manipulated in a mild condition, showing the potential in saving cost and energy.\u003c/p\u003e","manuscriptTitle":"Molecular-Squeeze Triggers Guest Desorption from Sponge-Like Macrocyclic Crystals","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-05-16 10:19:58","doi":"10.21203/rs.3.rs-4248303/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"76b76f6b-75b7-4bf3-aa8e-1994989cef34","owner":[],"postedDate":"May 16th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":31954556,"name":"Physical sciences/Chemistry/Supramolecular chemistry/Crystal engineering"},{"id":31954557,"name":"Physical sciences/Chemistry/Materials chemistry"}],"tags":[],"updatedAt":"2024-08-07T15:25:36+00:00","versionOfRecord":[],"versionCreatedAt":"2024-05-16 10:19:58","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4248303","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4248303","identity":"rs-4248303","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}