electrochemical and spectroscopic studies of interactions of mn(iii) complexes with nucleic bases and nucleosides

the complexes of mn(oac)3 and/or mn(acac)3 with nucleic bases and nucleosides (adenine, guanine, xanthine, adenosine and guanosine) have been synthesized in nonaqueous solution. polarographic and spectroscopic (ir and visible) methods have been used to establish the active site(s) on the imidazole and pyrimidine rings in the nucleic bases and nucleosides for the interaction with the mn(iii) complexes. infrared spectroscopic results, indicate the n.9 site for adenine, n.1 site for adenosine and n.7 site for guanosine are the most probable sites of interaction with mn(oac)3. in addition, these results emphasize a dichotomy between n.9 and n.7 sites in adenine and between n.7 and n.1 sites of guanosine and adenosine. in the case of mn(acac)3, the binding site for adenine changes to n.7, which could be accounted for the formation of the hydrogen bond between acetylaceton ligand and nh2 group.