Intermolecular and coordination reactions in the systems of copper(II) with adenosine 5′-monophosphate or cytidine 5′-monophosphate and triamines

Formation of molecular complexes as a result of non-covalent interactions between adenosine 5 ' -monophosphate (AMP) or cytidine 5 ' -monophosphate (CMP) and polyamines, 1,5-diamino-3-azapentane (dien) or 1,6-diamino-3-azahexane (2,3-tri), has been studied in metal-free systems. Based on the acid-base equilibrium changes, the composition and stability constants of the molecular complexes formed have been determined. Spectral analysis has revealed that the interaction centers in these adducts are protonated amine groups from the polyamine, phosphate groups and donor nitrogen atoms from the nucleotide. In the ternary systems of Cu(II) with AMP or CMP and polyamines, then or 2,3-tri, the composition and stability constants of the heteroligand complexes formed have been determined. The presence of the following complexes has been detected: Cu(CMP)(dien), Cu(AMP)(dien), Cu(CMP)(2,3-tri), Cu(CMP)(2,3-tri)(OH). Results of the equilibrium and spectral studies (Vis, IR, EPR, C-13, P-31 NMR) have shown that in the mixed complexes, all nitrogen atoms from the polyamine and oxygen atoms from the phosphate group of the nucleotide take part in the coordination. The donor nitrogen atoms N(1) and N(7) from AMP and N(3) from CMP are in the outer coordination sphere. (C) 2001 Published by Elsevier Science Ltd.