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 · Thu Feb 07 00:00:00 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]

---

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), Vol. 95:3; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

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