Investigation of the molecular structure of 4-(3-methyl-3-phenylcyclobutyl)-2-[2-(3-methyl-benzylidene)hydrazinyl] thiazole in the gas and solid phases

Abstract

In this study, the title Shiff base, C22H23N3S, was synthesized and examined by H-1 and C-13 NMR spectroscopy and X-ray analysis techniques. The crystal structure is stabilized by classical intermolecular N-H center dot center dot center dot N hydrogen bonding. The crystal packing is additionally stabilized by C-H center dot center dot center dot pi 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).