N -[4-(3-Methyl-3-phenyl-cyclobutyl)-thiazol-2-yl]- N ′-pyridin-2-ylmethylene-chloro-acetic acid hydrazide: Synthesis and configurational assignment based on X-ray, 1 H, and 13 C NMR and theoretical calculations

In this study, quantum chemical calculations based on the density functional theory have been carried out to examine the effects of N-[4-(3-methyl-3-phenyl-cyclobutyl)-thiazol-2-yl]-N′-pyridin-2-ylmethylene- chloro-acetic acid hydrazide. The calculated values are compared with the experimental data available for these molecules as a mean of validation of our proposed chemistry model. Aided by normal coordinate analysis and potential energy distributions, a confident vibrational assignment of all fundamentals is proposed herein. Additional support is given by 1H and 13C NMR spectra recorded with the sample dissolved in CDCl3 and by predicted chemical shifts at the B3LYP/6-31G(d)/6-311G+(d) levels obtained using the gauge-invariant atomic orbital method. The calculated HOMO and LUMO energies also confirm that the charge transfer occurs within the molecule. Thiazole-based compounds are potential storehouse for exploiting CH···O and CH···N hydrogen bonding interactions for molecular self-assembly.