Studies on some ternary complexes of copper(II) involving an amino penicillin drug

Multiple equilibrium studies by ph-metric measurements in the ternary copper(ii) complexes with ampicillin(amp) as ligand a and glycine(gly), dl-2-aminobutanoic acid(2aba), dl-3- aminobutanoic acid(3aba), 1,2-diaminopropane(dp), 1,3-diaminopropane(tp), dl-2,3-diaminopropanoic acid(dapa), dl-2,4-diaminobutanoic acid(daba) & dl-2,5-diaminopentanoic acid(ornithine) (orn) as ligands b show the presence of cuabh, cuab or cuah^-1 b ternary complex species. in the cuab species the binding of the ligands a and b is similar to their binding in their respective binary complexes. in cuabh^-1 species the deprotonation occurs with amp(a) ligand. the δlog k values indicate higher stabilities for the ternary complexes than the binary species. the cuab species with b = gly, 2aba, dapa & orn have been isolated and characterized. the conductivity measurements indicate that the complexes are non-electrolytes. magnetic susceptibility and electronic spectral data suggest a square pyramidal geometry for cuab with b = gly/2aba complexes and distorted octahedral geometry for cuab with b = dapa/orn. the vibrational spectra are interpreted to find the mode of binding of ligand to metal. the tg/dta studies reveal that the complexes decompose in three steps, indicating non-involvement of hydrated or coordinated water molecules in the complex. the cyclic voltammograms indicate a quasi reversible cu^2+/cu^+ couple. the antimicrobial activity and ct-dna cleavage ability of the complexes show higher activity for ternary complexes.