Integrative Experimental and DFT Study of Sulfonyl Hybrid Benzimidazole‐Based Zwitterions: Crystallography, HSA, and Electronic Properties

Abstract

In this study, two sulfonyl hybrid benzimidazole‐based zwitterions (ZI‐1, ZI‐2) are synthesized and isolated as pure non‐aqueous organic and aqueous inorganic fractions by the reaction of 2‐(o‐sulfamoylphenyl)benzimidazole with benzene sulfonyl chloride in dimethyl formamide under basic medium. The aim of this study was to investigate the structural, electronic, and intermolecular properties of sulfonyl hybrid benzimidazole‐based zwitterions with the support of experimental and computational studies. The structures of sulfonyl hybrid benzimidazole‐based zwitterions were determined by X‐ray crystallography. The Hirshfeld surface analysis (HSA) serves as fingerprint analysis to find the molecular interactions in the crystalline state and to quantify their contributions toward crystal packing. In supramolecular assembly, the O atom of sulfonyl group and N atom of protonated imidazole ring are red highlighted spots, which confirms the short contact interaction in both molecules. The crystallographic obtained bond lengths and bond angles were compared with calculated results, which supports the experimental obtained results. Furthermore, single‐crystal data‐based theoretical studies for the determination of UV–visible, FT‐IR, ¹H NMR, ¹³C NMR, natural bond orbital (NBO), Global reactivity descriptors, molecular electrostatic potential (MEP), frontier molecular orbital (FMO), dipole moment, polarizability, Mullikan charges, and NPA charges were carried out by DFT studies.