Synthesis and characterization of some vanadyl Schiff base complexes

Neutral tetradentate N2O2 type complexes of vanadium (IV) have been synthesized by metal ion catalyzed template process in which aromatic/aliphatic diamines such as orthophenylenediamine / ethylenediamine were allowed to undergo Schiff base condensation with salicylaldehyde having chlorine substitution at 3 or 5 position, in the presence of vanadyl sulphate in ethanolic medium, the stoichiometric ratio between amine, aldehyde and metal salt being 1:2:1. All the complexes were characterized on the basis of their micro analytical, spectral, magnetic and conductivity data. Micro analytical data indicate formula of the complexes to be of the type [VO (SB1-4)] where SB stands for the binegative anion of the Schiff base H2SB1-4. H2SB1= N, N' - bis (3-chloro salicylidene) ethylenediamine H2SB2 = N, N' - bis (3-chloro salicylidene ) orthophenylenediamine H2SB3 = N, N' - bis (5-chloro salicylidene) ethylenediamine H2SB4 = N, N' -bis (5-chloro salicylidene ) orthophenylenediamine. Conductivity data supports non electrolytic nature of the complexes as the value lies in the range of 6 - 10 units. Infra red spectral study suggests coordination to the vanadyl ion through azomethinic nitrogen and phenolic oxygen. Magnetic moment data along with electronic spectral bands corroborate square pyramidal geometry.