Synthesis, characterization and biological activity of metal complexes with 4-aminoantipyrine Schiff bases of 5-chloro salicylaldehyde and 3-ethoxy salicylaldehyde

摘要

A series of transition metal complexes of Cu~(II), Ni~(II), Co~(II), Zn~(II) and VO~(IV) with biological activity, have been synthesized involving the Schiff bases 2,3-dimethyl-1-phenyl-4-(5-chloro-2-hydroxy benzylideneamino)-pyrazol-5-one (5-C1 SALAAP), L1 and 2,3-dimethyl-1-phenyl-4-(3-ethoxy-2-hydroxy benzylidcneamino)-pyrazol-5-one (3-OEt SALAAP), L2 derived from 4-amino antipyrine and S-chloro saIicylaIdehyde/3-ethoxy salicylaldehyde respectively. Structural features were obtained from their IR, 'H NMR, ESI Mass, UV-Vis, thcrmo gravimetric studies, elemental analysis, molar conductance and magnetic susceptibility measurements. Molecular modelling studies were also carried out to confirm the geometries of the complexes. The Schiff bases act as tridentate ligands which coordinate through the azomcthine nitrogen, phenolic oxygen and carbonyl oxygen of antipyrine ring. The ligands and their metal complexes were screened for their antibacterial activity against Staphylococcus aureus and E. coli. The results showed the metal complexes to be biologically active.