INVESTIGADORES
FAGALDE Florencia
artículos
Título:
Tuning of the Reorganization Energies by Innocent Co-Ligands in Novel Mixed-Valent Dinuclear Ruthenium Complexes
Autor/es:
GARCÍA POSSE, MÓNICA E.; VERGARA, MÓNICA M.; FAGALDE, FLORENCIA; KATZ, NÉSTOR E.
Revista:
POLYHEDRON
Editorial:
Elsevier Science Ltd.
Referencias:
Lugar: Amsterdan Holanda; Año: 2003 vol. 22 p. 465 - 471
ISSN:
0277-5387
Resumen:
Two novel mixed-valent ruthenium complexes, of formulae [(tpy)(bpy)RuII(pz)RuIII(edta)]-  and [(CN)4RuII(bpz)RuIII(edta)]3_ (where tpy=/2,2?:6?,2?-terpyridine, bpy=2,2?-bipyridine, pz=/pyrazine, bpz=/2,2?-bipyrazine, edta=/ethylenediaminetetraacetate), were prepared and spectroscopically characterized in aqueous solutions and as solid salts with suitable counterions. For comparison purposes, two new ruthenium complexes: a dinuclear species, of formula [(CN)4RuII(bpz)RuII(NH3)5], and a trinuclear species, of formula {(CN)4RuII(bpz)[RuII(NH3)5]2}2_, were also prepared and characterized in aqueous solutions. From spectral data of metal-to-metal charge transfer (MMCT) absorption bands, a Hush analysis was made, and the reorganization energies for the intramolecular electron transfers were calculated. A dramatic change in these values was disclosed when comparing both mixedvalent species, which can be explained on the basis of the influence exerted by the ?innocent? co-ligands (polypyridines or cyanides) bonded to the ruthenium centers. This tuning is an important factor in devising molecular devices for energy conversion. Keywords: Mixed-valence; Ruthenium complexes; Intramolecular electron transfer; Inverted region; Reorganization energies; Energy conversion