Charge separation in the photoelectron transfer reaction between dicyanobis(2,2'-bipyridine)ruthenium(II) and the ferricyanide ion in a polyelectrolyte solution
The effect of the positive polyelectrolyte, polybrene, on the photoinitiated electron transfer reaction from the neutral photosensitizer Ru(bpy)/sub 2/(CN)/sub 2/ to the negative quencher Fe(CN)/sub 6//sup 3 -/ in aqueous solution was studied. The results of bleaching experiments carried out at 440 nm showed that the presence of the polyelectrolyte causes net separation of the charged products with a quantum yield of 0.91 +- 0.15 and it was found that their disappearance could be described by a composite first- and second-order rate law in the pH range 2 to 12.2 with a second-order rate constant of 4.0 x 10/sup 9/ M/sup -1/ s/sup -1/ in the absence of added acid or alkali. This is believed to be possibly the first regeneration of reactants observed following polyelectrolyte-assisted charge separation of products of a photoinitiated electron transfer reaction. The rate of quenching in the presence of polybrene was found to be reduced to about 60% of that measured in the absence of polybrene. The effects of variation of coverage of the polyelectrolyte by ferricyanide were also studied on this system. The absorption spectrum of the lowest excied state of Ru(bpy)/sub 2/(CN)/sub 2/ was determined in the region 310 to 580 nm. The relation of this work to the conversion and storage of solar energy is discussed. 4 figures, 2 tables.
- Research Organization:
- Hebrew Univ., Jerusalem, Israel
- OSTI ID:
- 5343610
- Journal Information:
- J. Phys. Chem.; (United States), Vol. 84:11
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
14 SOLAR ENERGY
FERRICYANIDES
ELECTRON TRANSFER
RUTHENIUM COMPLEXES
ABSORPTION SPECTRA
ELECTROLYTES
ENERGY STORAGE
PH VALUE
PHOTOGALVANIC CELLS
QUENCHING
SOLAR ENERGY
SOLAR ENERGY CONVERSION
COMPLEXES
CONVERSION
ELECTROCHEMICAL CELLS
ENERGY
ENERGY CONVERSION
ENERGY SOURCES
EQUIPMENT
IRON COMPLEXES
PHOTOELECTROCHEMICAL CELLS
RENEWABLE ENERGY SOURCES
SOLAR EQUIPMENT
SPECTRA
STORAGE
TRANSITION ELEMENT COMPLEXES
400500* - Photochemistry
140505 - Solar Energy Conversion- Photochemical
Photobiological
& Thermochemical Conversion- (1980-)