Abstract
Pt(IV), Au(III) and Pd(II) complexes of Schiff bases derived from 2-furaldehyde and 4-amino antipyrine (4APF) are reported and characterized based on elemental analyses, IR 1H-NMR, electronic spectra, molar conductance, and thermal analysis (TG/DTG). The complexes are found to have the formulas [Pt(4APF)Cl]Cl3, [Pd(4APF)]Cl2 and [Au(4APF)(Cl)2]Cl. The molar conductance data reveal that all the metal chelates of the 4APF ligand are electrolytes with different numbers of ionizable chloride ions. IR spectra show that 4APF is coordinated to the metal ions in a bi-dentate situation, with ON donor sites of azomethine–N and furan-O, whereas the Pt(IV) metal ions is coordinated to the 4APF in a tri-dentate situation with ONO donor sites of azomethine–N, furan-O, and carbonyl-O. The thermal behavior of these chelates shows that the hydrated complexes lose water molecules of hydration in the first step and is followed by decomposition of the anions and ligand moieties in the respective steps. The synthesized ligands, in comparison to their metal complexes, were also screened for their antibacterial activity against bacterial species as well as fungi. The activity data show the metal complexes to be more potent antimicrobial than the parent Schiff base ligand.