Synthesis and characterization of trivalent chromium, manganese, iron and cobalt complexes with Schiff bases derived from 4-amino-5-mercapto-l ,2,4-triazoles

Abstract

Coordination complexes of Cr(III), Mn(III), Fe(III) and Co(III) with Schiff bases derived from 3-substituted phenyl-4-amino-5-mercapto-1,2,4-triazoles and anisaldehyde, veratraldehyde, salicylaldehyde, 2-hydroxyacetophenone have been prepared and charac terized by elemental analyses, electrical conductance, magnetic moments and spectral (elec tronic, IR, ¹H NMR, FAB mass) data. On the basis of spectroscopic studies Schiff bases L₁H and L₂H are monobasic bidentate towards Cr(III), Mn(III), Fe(III) and Co(III) having composition [M (L_1or2)₃] and Schiff bases L₃H₂ and L₄H₂ are dibasic tridentate towards all the metals with composition [ML₃ (H₂O)₂X] and [ML₄(H₂O)₂X] where M = Cr(III), Mn(III), Fe(III) and Co(III) and X = Cl and OAc. Various physicochemical data suggest a six-coordinated octahedral geometry for all the complexes. Ligands and their complexes have been screened for their antibacterial activity against gram-positive and gram-negative

bacteria.