Photophysical, antioxidant, antibacterial and NBO, LOL, ELF analysis of alkyl groups substituted calix[4]resorcinarenes

In our work to investigate the photophysical, antibacterial, theoretical and topological analysis of four C-alkyl calix[4]resorcinarenes (C4RAs). The solvatochromism and photophysical properties of C4RAs in different solvents were recorded in both UV-Visible and fluorescence spectral studies. The total antioxidant capacity and antibacterial activity of four C4RAs were evaluated by phosphomolybdate assay and kirby-bauer method. Theoretical parameters such as HOMO, LUMO, energy gap and Mulliken atomic charges and NBO were optimized by DFT B3LYP 6-311G method. From the results of HOMO and LUMO energies were used to determine the theoretical parameters of four C4RAs. The nucleophilic and electrophilic substitution reactivity of four C4RAs were analyzed by molecular electrostatic potential map analysis. Natural bonding orbital analysis was used to determine the intramolecular charge transfer within the energy difference between acceptor and donor orbitals. The non-covalent interactions of four C4RAs were characterized by LOL and ELF topological analysis.