1,10-(phenanthroline)-bis{1-alkyl-2-(arylazo)imidazole} ruthenium(II) perchlorate: Synthesis, spectral study, and electrochemistry

The hetero-tris-chelates of the formula [Ru(Phen)(RAaiR')(2)](ClO4)(2) (Phen = 1,10-phenanthroline, RAaiR' = 1-alkyl-2-(arylazo)imidazole, p-R-C6H4-N=N-C3H2-NN-1-R', where R = H (a), Me (b), Cl (c) and R' = Me (II), Et (III), CH2Ph (IV)) have been isolated from the reaction of ctc-[RuCl2(RAaiR')(2)] with AgNO3 + Phen or [Ag(Phen)(2)](ClO4) in acetone at 40A degrees C in dark followed by the addition of NaClO4 (aq). The stereo-chemistry of the complexes have been supported by H-1 NMR data. Considering the arylazoimidazole and phenanthroline moietie there are twenty different carbon atoms in the molecule which gives a total of twenty different peaks in the C-13 NMR spectrum of complex Ia. Cyclic voltammograms show Ru(III)/Ru(II) couple at 1.3-1.4 V vs SCE along with three successive ligand reductions.