Structure elucidation {single X-ray crystal diffraction studies, Hirshfeld surface analysis, DFT} and antibacterial studies of sulfonamide functionalized Schiff base copper (II) and zinc (II) complexes

Abstract

Microbial infections tremendously affect the human health and can be cured by antimicrobial agents. In this regard, the copper and zinc complexes of a sulfonamide functionalized Schiff base have been synthesized. The molecular structures confirm that the ligand has acted as N,O- chelator and stabilized the metal complexes by forming six membered ring system. The square planar and octahedral geometries have been assigned to the synthesized complexes on the basis of various spectral analyses. The crystal structure data has been utilized to calculate UV-visible, FT-IR, NMR, HOMO-LUMO energies, molecular electrostatic potential and frontier molecular orbitals using density function theory. The relative stability of the complexes was predicted using global chemical reactivity. The synthesized metal complexes were screened against different bacterial strains. It was concluded that both compounds were effective against almost all microbes. The compound 2 is more potent as compared to 1 with highest activity against Halomonas halophila (22.4 ± 1.2 mm; MIC 79 ± 5 µg). The compounds were further evaluated in terms of docking studies to find out their antimicrobial studies which confirmed that complexes have better antibacterial trends.