Synthesis and Characterization of Some Biologically Active Copper Complexes for Microbial Applications

Abstract

In this study, in order to verify our hypothesis amino acid base copper complexes have been prepared for biological application. Reaction of tcydan and Cu(C104)2 6H20 with nucleobases (adenine, hypoxanthine and theophylline) gave three tcydan—metal—amino-acid base complexes, Cu(tcydan)(ade)] .C104.2H20 (1), [{ Cu(tcydan) }2(hypoxanth).(CIO4)3 (2) and H20/CH3 [Cu(tcydan)(theophy)]3.(C104)3.2H20 (3). The complexes were prepared in H CN media at room temperature under pH 8-9. The crystal structures were determined by X-ray diffraction. In the structure of complex 1, the square-pyramidal Cu 2+ ion binds to an adenine ligand through the deprotonated N(9) and to four nitrogens of a tcydan ligand, and an interligand hydrogen bond is formed between the secondary amino nitrogen of tcydan and the ring nitrogen N(3) of the base. In complex 2, two square-pyramidal Cu2 ions bind to a xanthine ligand, one through N(7) with the formation of a hydrogen bond between the exocyclic oxygen 0(6) of the base and the secondary amino nitrogen of a tcydan ligand, and the other through the deprotonated N(9) with the formation of a hydrogen bond between N(3) of the base and the amino nitrogen of tcydan. In the structure of complex 3, the square-pyramidal Cu 2+ ion binds to a theophyllinato ligand through N(7) and four nitrogens of a tcydan ligand with the formation of a hydrogen bond between 0(6) of the base and amino group of tcydan, as observed in 2 and 3. In summary, the adenine complex 1 involves the metal-N(9) bonding with the formation of an N(3) hydrogen bond. On the other hand, the absence of the possible metal bonding to N(7) or N(I) of adenine might be due to a steric repulsion, intramolecular interligand N(tcydan)-H ...between amino groups of tcydan and the N(6) amino group when the metal ion binds to N(7)or N(l) of the base. Synthesized Cu-complexes are quite capable of removing Fecal coliform (FC) from water.