Zinc(II) and Cadmium(II) complexes containing imidazole ring: Structural, spectroscopic, antibacterial, DFT calculations and Hirshfeld surface analysis

Abstract

Two 2-D and 3-D supramolecular complexes [Zn(L)2](NO3)2·2CH3OH (1) and [Cd(L)2(NO3)2] (2) (L = 2-(4-imidazolyl)-4-methyl-1,2-quinazoline-N3-oxide) were synthesized and characterized by IR, UV–Vis, fluorescence spectroscopy and elemental analysis. X–ray crystallography reveals that 1 and 2 have 2:1 ligand-to-metal ratio. Zn(II) complex 1 had slightly distorted octahedral geometry with two non-coordinated nitrate anions and assembled into fishnet-like 2-D and even M-shape 3-D skeleton, while six-coordinated Cd(II) complex 2 had a distorted octahedral geometry included two coordinated nitrate anions and formed an infinite 2-D layered skeleton, and even a wavy 3-D supramolecular network. Furthermore, antimicrobial activities of all compounds were also investigated. Density Functional Theory (DFT) calculations were carried out to ascertain the optimum geometry structures of both complexes and the calculated HOMO and LUMO energies were presented. The electronic transitions and spectral character of complexes were discussed by TD-DFT calculations. Non-covalent interactions among both complexes were quantified using Hirshfeld surface analysis.