Crystal structure analysis of (E)-N-(3,5-dimethylphenyl)-2-(substituted benzylidene)thiosemicarbazone: Experimental and theoretical studies

摘要

Two novel thiosemicarbazone derivatives had been synthesized and characterized by FT-IR, nuclear magnetic resonance, and elemental analysis. Single crystal X-ray diffraction analysis showed that compound1belongs to triclinic system in P-1 space group and compound2belongs to monoclinic system in C2/c space group. It could be seen from the determined crystal structure that the central skeleton (sic)N-NH-C(S)-NH- of both thiosemicarbazone compounds have good planarity. Density functional theory (DFT) calculations were done using B3LYP/6-31+G(d, p) basis set and the calculated results are in good agreement with the experimental data. In addition, the UV-visible absorption spectrum was estimated based on TD-DFT quantum chemistry calculations. Likewise, the simulated absorption spectrum is very consistent with the experimental data. Combining Hirshfeld surface analysis and molecular structure, it was found that the intermolecular hydrogen bond N-H center dot center dot center dot S(sic)C constitutes central symmetric dimerS22, we investigated the reduced density gradient function and the independent gradient model, which provided a deeper insight into the intermolecular and intramolecular interaction force of the compounds. The frontier molecular orbital analysis and molecular electrostatic potential were also discussed by theoretical calculations.