Dioxidovanadium(V) complexes of a tridentate ONO Schiff base ligand: Structural characterization, quantum chemical calculations and in-vitro antidiabetic activity

Two new dioxidovanadium(V) complexes [V(O)(2)(L)]Him 1 and [V(O)(2)(L)]H2Meim 2, incorporating tridentate ligand Nicotinic acid (2-hydroxy-3-methoxy-benzylidene)-hydrazide (H2L) and imidazoles (Him = imidazole and H2Meim = methylimidazole) was substantiated. The crystal structures of both complexes were solved by single-crystal X-ray analysis. In both complexes, the V(V) center is coordinated by ONO donar set of L2(-) ligand and two oxido groups in a distorted square pyramidal geometry. UV-visible spectra, infrared spectra and electrochemical properties of both complexes were also reported. Room temperature magnetic susceptibility was performed to disclose the diamagnetic nature of complexes 1 and 2. The quantum chemical calculations authenticated the molecular structures and reactivity of the complexes. Antidiabetic activities of the complexes have also been investigated. An antidiabetic feature like alpha-amylase and alpha-glucosidase inhibition studies made them promising agents as inhibitors of insulin enzyme. (C) 2020 Elsevier Ltd. All rights reserved.