Synthesis and characterization of copper(II), nickel(II) and cobalt(II) complexes with a Schiff base derived from 3-formylsalicyclic acid and thiocarbohydrazide

Abstract

A series of mono and dinuclear complexes of the type Na 2 [M{(3-fsa) 2 -TCH}(H 2 O)n]mH 2 O and [M 2 {3-fsa) 2 -TCH)(H 2 O)n]mH 2 O, where (3-fsaH 2 ) 2 -TCH is a Schiff base derived from 3-formyl salicylic acid and thiocarbohydrazide, n, m = 0, 1, 2 and M = Cu II , Co II and Ni II have been synthesized and characterized on the basis of elemental analysis, thermal analysis, molar conductivity, magnetic moment, infrared and electronic spectral data. The results indicate that the mononuclear Cu II and Ni II complexes are square planar; where as the mononuclear Co II complex is tetragonal pyramidal with water molecules at the apical position. Antiferromagnetic spin exchange in dinuclear Cu II complexes, subnormal magnetic moment values in dinuclear Ni II complexes and existence of mixed spin state of dinuclear Co II complexes comprising of a high and low spin Co II ion have been established. The fungi toxicities of the complexes against some fungal pathogens have been studied.