Synthesis and Characterization of Mixed Ligand Complexes of Cu(II)-Oxalate-Amino Acids (Aspartic acid and Cysteine)

Abstract

Coordination chemistry of transition metals has been interest for several years. Copper(II) amino acid complexes in recent years have been receiving much attention 1. The complexes of copper are particular interest due to their biological and antitumor properties 2-5. Copper(II) can inactivate the HIV protease 6. The ternary complexes of copper(II) plays an important role in biological processes. Proteins constitute one the most common classes of substances present in biological systems. Their chemical properties are of fundamental importance to understand cell mechanisms as membrane transport, secretion or digestion Amino acids are the building units of all proteins and enzymes 7. Amino acids have two principal potentially active sites in the formation of complexes, the acid carboxyl group and the basic amino group. However, natural amino acids can also include other functional groups in the chain during the peptide bond formation with sites for chemical activity in the peptide chains 8. Preparation and characterization of Cu(II) complexes with amino acids also investigated 9-11. The objective of this work involved the preparation and characterization of ternary complexes of copper(II) with oxalate as primary ligand and amino acids (aspartic acid, cysteine,) as secondary ligand. All the chemicals were of high purity and were used as purchased, without any further purification. Copper(II) nitrate, oxalic acid, L-aspartic acid, cysteine, methanol were used throughout this work. All experiments were carried out in open air. Nano pure-quality water and the ethanol of Merck were used. All experimental were carried out in open air.