Investigation of the molecular structure in the gas and solid phases
What is it about?
In this study, the title Shiff base, C22H23N3S, was synthesized and examined by 1H and 13C NMR spectroscopy and X-ray analysis techniques. The crystal structure is stabilized by classical intermolecular N—H...N hydrogen bonding. The crystal packing is additionally stabilized by C—H...π interactions. It has been observed that the compound can exist in two different tautomeric forms, and experimental and theoretical studies were carried out on these tautomeric structures. For this purpose, the gas phase of the compound was optimized by density functional theory (DFT) using the B3LYP/6-311G(d) method, which allowed for the structural parameters (bond angles, bond lengths and dihedral angles), as well as the frontier molecular orbitals (FMO), to be examined. In addition, stable structures of the two tautomers in the solid phase were obtained using Quantum ESPRESSO under periodic boundary conditions (PBC).
Why is it important?
In the light of the biological effects mentioned above, the structure of the new Schiff base 4-(3-methyl-3-phenylcyclobutyl)-2-[2-(3-methylbenzylidene)hydrazinyl]thiazole was confirmed by IR, 1H NMR, 13C NMR and X-ray diffraction techniques. The single crystal, which may be in two tautomeric structures, has been studied both experimentally and theoretically. The minimum-energy values of the two tautomeric structures in the gas phase were calculated using the GAUSSIAN09 program (Frisch et al. , 2009) and the lattice energies in the solid phase of the two tautomeric structures. This was carried out under periodic boundary conditions (PBC), which were calculated using the Quantum ESPRESSO 6.2.1 packag