TUNING OF EXCITED-STATE REDUCTION POTENTIALS VIA EXPANDED PI-SYSTEMS - SYNTHESIS AND CHARACTERIZATION OF [RU(2,3-DI(2'-PYRIDYL)BENZO(G)QUINOXALINE)3](PF6)2

The synthesis of [Ru(dpb)3](PF6)2 (dpb = 2,3-di(2'-pyridyl)(benzo(g)quinoxaline)) is described. The electrochemical and spectral properties are examined and compared to related complexes. These properties follow the trends observed for homologous species, and indicate that the principal features controlling the electrochemical and spectral properties are the ligand reduction potential and the steric crowding around the metal center. The molecule shows an extremely low energy emission spectrum which is consistent with predictions based on the energy gap law.