Reaction of adenine and guanine with [Ru(RaaiR′)2(EtOH)2](ClO4) 2.: Spectral and electrochemical characterization of the products [RaaiR′=1-alkyl-2-(arylazo)-imidazole]

[Ru(RaaiR')(2)(EtOH)(2)](ClO4)(2) [RaaiR' = 1-alkyl-2-(arylazo)imidazole, p-R-C6H4-N=N-C3H2N-N(1)-R', R=H (a), Me (b), Cl (c), R' = Me (1, 3), Et (2, 4)] reacts with nucleobases [NB-adenine (A), guanine (G)] in aqueous EtOH to give red-violet mixed ligand complexes of the type [Ru(RaaiR')(2)(NB)(H2O)](ClO4)(2). The solution electronic spectra exhibit a strong MLCT band at 540-560 nm in MeCN. The cyclic voltammogram shows a Ru-III/Ru-II couple at 1.3-1.4 V versus Ag/AgCl along with three successive ligand reductions.