Distorted square-antiprism geometry of new zirconium (IV) Schiff base complexes: Synthesis, spectral characterization, crystal structure and investigation of biological properties

A series of zirconium (IV) Schiff-base complexes formulated as [Zr (Lx)2] and [Zr (Lx′)2] were synthesized by reaction of tetradentate salicylaldimine Schiff-base ligands with [Zr (acac)4] in methanol. These ligands are as follows: H2Lx and H2Lx′ (x = x′ = 1,2,3,4). The new complexes have been characterized using FT-IR, lH NMR, 13C{1H} NMR spectroscopic techniques, elemental analyses (CHN) and the crystal structure of Zr (L3)2, Zr (L1′)2 and Zr (L3′)2 were determined by X-ray crystallography. The crystal structure analysis revealed that the coordination environment of the metal in all complexes is eight-coordinate occupied by N2O2 sets of the coordinated ligands in distorted square-antiprism geometry. The in vitro biological screening effects of the synthesized compounds were tested against different microbial kinds and the zirconium (IV) complexes exhibit antimicrobial activity.