Structure and antioxidant superoxide dismutase activity of copper(II) hydrazone complexes

Abstract

Three new mixed ligand hydrazone complexes viz., [Cu(L)(neocuprin)]NO 3 .H 2 O 1, [Cu(L)(HL)]ClO 4 2 and [Cu 2 (2-(2-pyridyl)benzimidazole) 2 (L) 2 ]ClO 4 3 (L = N'-[(E)phenyl(pyridin-2-yl)methylidene]furan-2-carbohydrazide) have been synthesized by the biomimetic synthesis strategy and their structures were determined by single crystals X-ray analysis. The effect of differing contagious, as well as the rotational conformational versatility of HL, was demonstrated by the difference in structures of complexes 1-3. These complexes exhibited the antioxidant superoxide dismutase enzymatic activity. The geometry of copper(II) atom in complex 1 is distorted square pyramidal while in complexes 2 and 3 the geometries around copper(II) atoms are distorted octahedral. Magnetic measurements and epr spectroscopy of binuclear complex 3 have shown antiferromagnetic exchange interaction with a coupling constant (J) =-10.87 cm-1. Electronic and spectral properties of these newly synthesized hydrazone complexes (1-3) are interpreted by DFT and TDDFT calculations. The results reveal that molecular structures have significant effect on antioxidant superoxide activity. Such biological experimental values (antioxidant SOD activity data) are indicative of the promising application of these complexes into the bioinorganic chemistry of superoxide dismutase.

Synthesis, Spectral Characterization and in vitro Antidiabetic Properties of Oxovanadium(IV) Complexes with 2-{(E)-Pyridin-4-yl[2-(pyridin-2-yl)hydrazinylidene]methyl}pyridine

“…The in-plane deformation mode of the pyridine ring 620-520 cm -1 in all the present vanadium complexes, suggests the coordination of pyridine nitrogen [20]. The bands centred at 1445, 1320 and 865 cm -1 exhibited due to the presence of free nitrate ion of all the present vanadium complexes [21]. These findings clearly suggest the coordination of imino nitrogen atoms and pyridine nitrogen atoms donor sites to the vanadium atom and therefore tridentate neutral nature of the coordinated Schiff base (Scheme-I) may be accepted.…”

Crystal structure ofN′-[4-(dimethylamino)benzylidene]furan-2-carbohydrazide monohydrate

“…These kinds of Schiff bases were used for preparing complexes with transition-metal or lanthanide ions. The ligand acts in a bidentate or tridentate fashion, as reported in the literature [ABUKIU (Singh et al, 2017), DAZMEX (Haba et al, 2005), FIGMEO (Maurya et al, 2005), and VIVGOY (Alagesan et al, 2014)]. One organometallic palladium complex was found containing a metalcarbon bond in a six-membered ring (TAPXEQ; Qian et al, 2017).…”

Co(III) and Cu(II) benzimidazole Schiff base complexes: Synthesis, Characterization and DNA binding and cleavage activity

“…This band is assigned to the transition 1 A 1g → 1 T 2 g, suggesting that there is an octahedral geometry around Co (III) ion 20 . Another band at around 396-438 nm refers to the charge transfer band in all the complexes 21 . The Cu(II) complexes C3…”