Solvent control of electronic distribution in the MLCT excited states of ((bpy)(CO) sub 3 Re sup I (4,4 prime -bpy)Re sup I (CO) sub 3 (bpy)) sup 2+

Journal Article · Wed Feb 06 23:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100156a017· OSTI ID:5201872

Tapolsky, G; Duesing, R; Meyer, T J ^[1]

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1. Univ. of North Carolina, Chapel Hill (USA)

In the ligand-bridged complex ((bpy)(CO){sub 3}Re{sup I}(4,4{prime}-bpy)Re{sup I}(CO){sub 3}(bpy)){sup 2+} (bpy is 2,2{prime}-bipyridine; 4,4{prime}-bpy is 4,4{prime}-bipyridine), either Re {yields} bpy or Re {yields} 4,4{prime}-bpy excitation in acetonitrile or propylene carbonate leads to an equilibrium mixture of two metal ligand charge transfer (MLCT) excited states. They are based on Re{sup II}(bpy{sup {center dot}{minus}}) or Re{sup II}(4,4-bpy{sup {center dot}{minus}}). The excited states are formed rapidly ({le}5 ns) upon excitation. They are interconverted by intramolecular electron transfer processes which, at room temperature, are rapid on the time scale for excited-state decay. As shown by transient absorbance measurements, the distribution between excited states is temperature and solvent dependent with polar solvents favoring Re{sup II}(4,4-bpy{sup {center dot}{minus}}). Changes in solvent can be used to change the distribution between excited states and, thus, the electronic distribution within the molecule following MLCT excitation. In fluid solution, excited-state lifetimes for the equilibrium mixture between states were 870 {plus minus} 20 ns in 1,2-dichloroethane, 365 {plus minus} 10 ns in acetonitrile, and 325 {plus minus} 10 ns in propylene carbonate.

• OSTI ID: 5201872
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 95:3; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ABSORPTION SPECTROSCOPY
AZINES
BIPYRIDINES
COMPLEXES
DATA
ELECTRON TRANSFER
ELECTRONIC STRUCTURE
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
HETEROCYCLIC COMPOUNDS
INFORMATION
MEDIUM TEMPERATURE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PYRIDINES
RHENIUM COMPLEXES
SPECTROSCOPY
TRANSITION ELEMENT COMPLEXES