Synthesis, structure, spectra, NLO behavior, and in-silico study on anti-tumor and anti-tuberculosis efficacy of (Z)-3-((Z)-3-phenylallylidene)benzo[4,5]imidazo[1,2-c]thiazole-1(3H)-thione

Abstract

In this study, we report the synthesis of (Z)-3-((Z)-3-phenylallylidene)benzo[4,5]imidazo[1,2-c]thiazole-1(3H)-thione (ThBMT). This compound belongs to an important group of molecules containing two or more heterocyclic moieties. ThBMT was experimentally characterized using IR and NMR spectroscopy. The absolute 3D structure of ThBMT was determined by single-crystal X-ray diffraction, revealing crystallization in the monoclinic space group P21/c with four molecules in the unit cell. First principle theoretical calculations were carried out via the Density Functional Theory (DFT) method with B3LYP and B3LYP-GD3(BJ) functionals using the 6–311++G(d, p) basis set. The geometrical parameters of ThBMT were analyzed and compared to those of optimization, which were found to be consistent. The crystal packing and their intermolecular interactions were studied by Hirshfeld surface analysis, revealing that the most common interactions were C-H⋅⋅⋅N and C-H⋅⋅⋅S. Furthermore, theoretical vibrational wavenumbers were computed, assigned, and compared to the experimental ones. The (1H, 13C) NMR chemical shifts were calculated and compared with experimental values. The compound's nonlinear optical (NLO) properties were also investigated to understand its potential applications in optoelectronics, and compared to those of the benzimidazole fragment. The results showed promising NLO characteristics. Molecular docking and in silico ADMET studies were reported to highlight the biological behavior of ThBMT, indicating anti-tuberculosis properties, and anti-tumor activities against HeLa and HepG2 cancer cell lines.