Luminescence and intramolecular energy-transfer processes in isomeric cyano-bridged Rhenium(I)-Rhenium(I) and Rhenium(I)-Ruthenium(II)-Rhenium(I) polypyridyl complexes

Journal Article · Wed Dec 09 04:00:00 EST 1992 · Inorganic Chemistry; (United States)

DOI:https://doi.org/10.1021/ic00051a016· OSTI ID:6836842

Kalyanasundaram, K; Graetzel, M; Nazeeruddin, M K ^[1]

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1. Institut de Chimie Physique, Lausanne (Switzerland)

Mixed-metal and homometal cyano-bridged polypyridyl complexes of Re(I) and Ru(II) such as [(CO)[sub 3](bpy)Re-CN-Re(bpy)(CO)[sub 3]][sup +], [(CO)[sub 3](bpy)Re-NC-Ru(bpy)[sub 2]-CN-Re(bpy)(CO)[sub 3]][sup 2+], and [(CO)[sub 3](bpy)Re-CN-Ru(dcbpy)[sub 2]-NC-Re(bpy)(CO)[sub 3]][sup 2+] (bpy = 2,2[prime]-bipyridine and dcbpy = 4,4[prime]-dicarboxy-2,2[prime]-bipyridine) have been synthesized. Their spectroscopic, redox, and photophysical properties are reported. The lowest energy CT excited state in these complexes (Re-bpy or Ru-bpy CT) is emissive in fluid solutions. In the trinuclear complexes, intense absorption in the infrared region corresponding to intervalence (IT) transitions are reported in the CT excited state and partially oxidized species. Luminescence and redox properties have been used to assess intramolecular energy/electron-transfer processes between the terminal Re(I)-polypyridyl and central Ru(II)-polypyridyl units. The intervalence transitions and the excitation spectra for the Ru-based emission suggest efficient occurrence of energy transfer from the CT excited state of the Re-based chromophore to the Ru-based unit in both complexes [(CO)[sub 3](bpy)Re-NC-Ru(bpy)[sub 2]-CN-Re(bpy)(CO)[sub 3]][sup 2+] and [(CO)[sub 3](bpy)Re-CN-Ru(dcbpy)[sub 2]-NC-Re(bpy)(CO)[sub 3]][sup 2+]. A comparison is made between the N- and C-bonded isomers and also between Re-Ru-Re- and Ru-Ru-Ru-polypyridyl trinuclear complexes.

• OSTI ID: 6836842
• Journal Information: Inorganic Chemistry; (United States), Journal Name: Inorganic Chemistry; (United States) Vol. 31:25; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
AZINES
CHEMICAL PREPARATION
CHEMICAL REACTIONS
COMPLEXES
ELECTRON TRANSFER
EMISSION SPECTRA
ENERGY LEVELS
ENERGY TRANSFER
EXCITED STATES
HETEROCYCLIC COMPOUNDS
ISOMERIZATION
LIGANDS
LUMINESCENCE
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOLUMINESCENCE
PYRIDINES
REDOX POTENTIAL
RHENIUM COMPLEXES
RUTHENIUM COMPLEXES
SPECTRA
SPECTROSCOPY
STABILITY
SYNTHESIS
TRANSITION ELEMENT COMPLEXES