EPR study of the 1:1 complexes of chromium(III) and copper(II) with 5'-GMP and 5'-CMP

EPR investigation of Cr(III) and Cu(II) complexes with 5'-GMP and 5'-CMP gives information concerning the metal-nucleotide interaction and the symmetry of the coordination polyhedra. The interaction of Cr(III) with these nucleotides occurs mainly through the phosphate group in a pseudooctahedral geometry. In the case of Cu(II)-com plexes a dominant interaction of the metal with heterocyclic rings is observed. The phosphate group is also involved in these interactions. A local square-pyramidal symmetry occurs for both copper complexes Cu(II)-5'-CMP and Cu(II)-5'GMP, but the latter presents a rhombic distorted geometry. (C) 1997 Elsevier Science B.V.