New asymmetric N-heterocyclic-bridged mixed-valent dinuclear complexes of rhenium and ruthenium

wo new mixed-metal mixed-valent complexes, of formulae: [(CO)3(bpy)ReI(bpe)RuIII(NH3)5]4+ and [(CO)3(bpy)ReI(4-CNpy)RuIII(NH3)5]4+ (where bpy=2,2′-bipyridine, bpe=trans-1,2-bis(4-pyridil)ethene, 4-CNpy=4-cyanopyridine), were prepared and characterized as solids and in acetonitrile solutions. From th...

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Detalles Bibliográficos
Autores: Mellace, Maria G., Fagalde, Florencia, Katz, Néstor Eduardo
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2013
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/6936
Acceso en línea:http://hdl.handle.net/11336/6936
Access Level:acceso abierto
Palabra clave:Mixed-Valent
Ruthenium Complexes
Rhenium Complexes
Intramolecular Electron Transfer
Energy Conversion
https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
Descripción
Sumario:wo new mixed-metal mixed-valent complexes, of formulae: [(CO)3(bpy)ReI(bpe)RuIII(NH3)5]4+ and [(CO)3(bpy)ReI(4-CNpy)RuIII(NH3)5]4+ (where bpy=2,2′-bipyridine, bpe=trans-1,2-bis(4-pyridil)ethene, 4-CNpy=4-cyanopyridine), were prepared and characterized as solids and in acetonitrile solutions. From their spectroscopic, electrochemical and photophysical properties, the values for the reorganization energies λ and electronic coupling elements HAB for the metal-to-metal intramolecular electron transfers mediated by the N-heterocyclic bridges were calculated, using the Marcus–Hush formalism. For the 4-CNpy derivative, the reverse ruthenium-to-rhenium charge recombination—that should follow light excitation—is expected to be in the normal region, while for the bpe derivative this reaction is predicted to lie in the inverted region. The differences in redox potentials and in λ for both species account for these changes, which are relevant in the design of efficient photoconverters.