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

Abstract EN

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 Dlog 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 Cu2+ / Cu+ couple.

The antimicrobial activity and CT-DNA cleavage ability of the complexes show higher activity for ternary complexes.