Increasing transmission of electronic interaction in dinuclear unsymmetric mixed-valent ruthenium complexes

FAGALDE, FLORENCIA; GARCÍA POSSE, MÓNICA E.; VERGARA, MÓNICA M.; CATTANEO, MAURICIO; KATZ, NÉSTOR E.; ROMERO, ISABEL; PARELLA, TEODOR; LLOBET, ANTONI

POLYHEDRON

Elsevier science Ltd.

Lugar: Amsterdam , Holanda; Año: 2007 vol. 26 p. 17 - 23

0277-5387

The preparation and characterization by spectroscopic and electrochemical techniques of new dinuclear complexes of the type [(tpm)(bpy)RuII(L)RuII/III(NH3)5]4+/5+ (bpy = 2,2? -bipyridine), tpm = tris(1-pyrazolyl)methane, L = pz (pyrazine), 4,4?-bpy (4,4?-bipyridine), BPE (trans-1,2-bis(4-pyridyl)ethylene) and PCA (= 4-pyridinecarboxaldehydeazine), are described in this work. The analysis of the visible spectral data for the metal-to-metal charge transfer (MMCT) bands in the corresponding mixed-valent species [RubII ,  RuaIII] (Rub = Ru bonded to bpy; Rua = Ru bonded to NH3) allows the determination of the reorganization energies l and electronic coupling elements HAB for the intramolecular electron transfers RubII® RuaIII mediated by L. An increased transmission of the metal-to-metal electronic interaction is disclosed for this series, when comparing the distance dependence of HAB to that of the analogous series with trpy (2,2?:6?,2?-terpyridine) acting as a spectator ligand instead of tpm.