Quantum Chemical Calculations, Spectroscopic Studies and Biological Activity of Organic–Inorganic Hybrid Compound (2,2-Dimethylpropane-1,3-diammonium) Tetrachlorozincate(II)

Abstract

The paper describes the combinatorial study of experimental and theoretical on organic–inorganic hybrid compound $$[(\hbox {NH}_{3}{-}\hbox {CH}_{2}{-}\hbox {C}(\hbox {CH}_{3})_{2}{-}\hbox {CH}_{2}{-}\hbox {NH}_{3})]^{2+}[\hbox {ZnCl}_{4}]^{2-}$$ . The molecular structure of the studied compound was optimized theoretically, and the quantum chemical parameters were calculated. The vibratory bands emerging in the FT-IR were accurately assigned by animated mode. Molecular properties like frontier orbitals analysis, chemical reactivity descriptors, MEP mapping, dipole moments and natural charges were calculated under the DFT using the B3LYP/6-311++G(d,p)/LanL2DZ theory level. The theoretical data are found to be in good correlation with the experimental results obtained from various physicochemical techniques. The agar diffusion methods were used to study the antimicrobial assay of the compound against pathogenic strains, namely Escherichia coli and Salmonella typhi bacteria as well as selected fungi species: Candida albicans, Aspergillus niger and Aspergillus flavus. It was observed that Zn-ionic salt compound was selective and acts as a competitive inhibitor on E. coli compared to other strains. Molecular docking simulation was carried out to predict the nature of hybrid compound in the X-ray crystal structure of receptor of E. coli (PDB ID: 1ERQ) at active site to find out the suitable binding modality. The results of the simulation acknowledged the inhibitor nature of a new an organic inorganic hybrid compound. Cytotoxicity was also assessed in terms of $$\hbox {LD}_{50}$$ (lethal dose, 50%) using a brine shrimp lethality bioassay. Obtained brine shrimp lethality test results suggested that bioactive quality exists in the Zn compound which could be considered for its biological effects.