Synthesis and Characterization of Mono and Homo-Dinuclear, Cobalt(II), Nickel(II) and Copper(II) Complexes of the Schiff Base Derived from 3-Formylsalicyclic Acid and Hydroxylamine Hydrochloride

Abstract

Mono and homo-dinuclear cobalt(II), nickel(II) and copper(II) complexes

of the type of M{3fsa)₂-HyAm}(H2O)_n and M₂{(3fsa)₂-HyAM}(

H₂O)_n respectively, where {(3fsa)₂-HyAm} is a Schiff base

derived from 3-formyl salicylic acid and hydroxylamine hydrochloride,

n = 0, 1, 2, ... etc., have been isolated and characterized. The dinuclear

cobalt(II) complex has been found to have a mixed spin state consisting

of a high spin and a low spin cobalt(II) ion. Although strong antiferromagnetic

spin exchange interaction has been observed between the metal ions

of dinuclear copper(II) complex, the dinuclear nickel(II) complex exhibits

slightly lower magnetic moment value corresponding to two unpaired

electrons. The mononuclear cobalt(II) and copper(II) complexes are

paramagnetic while the mononuclear nickel(II) exhibits diamagnetic character.

The reflectance spectra of all the complexes are consistent with

observed magnetic moment values. IR spectra, thermal analysis and low

molar conductance values fully agree with the proposed structures. The

complexes have been evaluated as possible fungicides. The dinuclear

complexes show higher percentage of inhibition as compared to the

mononuclear ones. Copper(II) complexes of both the series exhibit maximum

fungitoxicity.