INQUINOA   21218
INSTITUTO DE QUIMICA DEL NOROESTE
Unidad Ejecutora - UE
artículos
Título:
Improving the Photosensitizing Properties of Ruthenium Polypyridyl Complexes Using 4-Methyl-2,2'-bipyridine-4'-carbonitrile as an Auxiliary Ligand
Autor/es:
MECCHIA ORTIZ, JUAN HUGO; VEGA, NADIA; COMEDI, DAVID; TIRADO, MONICA; ROMERO, ISABEL; FONTRODONA, XAVIER; PARELLA, TEODOR; MORÁN, EDUARDO; BORSARELLI, CLAUDIO; KATZ, NÉSTOR E.
Revista:
INORGANIC CHEMISTRY
Editorial:
AMER CHEMICAL SOC
Referencias:
Lugar: Washington; Año: 2013 vol. 52 p. 4950 - 4962
ISSN:
0020-1669
Resumen:
We report in this work the synthesis and spectroscopic, electrochemical, spectroelectrochemical, and photophysical characterization of a novel series of ruthenium polypyridyl complexes with 4-methyl-2,2′-bipyridine-4′-carbonitrile (Mebpy-CN) as an auxiliary ligand of general formula [Ru(bpy)3−x(Mebpy-CN)x](PF6)2 (x = 1−3) (with bpy = 2,2′-bipyridine). A significant increase in the lifetime and quantum yield of emission of the lowest 3MLCT excited state is disclosed when going from x = 1 to x = 3, evidencing an improvement of the photosensitizing properties with respect to [Ru(bpy)3](PF6)2. Furthermore, quenching by molecular oxygen of 3MLCT excited states of the three complexes produced singlet molecular oxygen (1O2) with quantum yield values higher than that of [Ru(bpy)3]2+ in CH3CN. The structure of the complex with x = 1 has been determined by X-ray diffraction. The photoconductivity of ZnO nanowires covered with this same complex is increased by an order of magnitude, pointing to its feasibility as a component of a DSSC. A new dinuclear complex with Mebpy-CN as a bridging ligand has also been prepared and characterized by physicochemical techniques. The derived mixed-valent species of formula [(bpy)2RuII(Mebpy-CN)RuIII(NH3)5]5+ displays a considerable metal−metal electronic coupling due to the delocalization effect of a nitrile group in the 4′ position of the bpy ring.