Unexpected salt effects on charge separation yields in phenothiazine derivatives-methylviologen systems

Journal Article · Thu Oct 23 00:00:00 EDT 1986 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100280a115· OSTI ID:7005447

Kawanishi, Y; Kitamura, N; Tazuke, S

Neutral salt effects on photoinduced electron-transfer reactions between the singlet excited state of phenothiazine derivatives (PTH) and methylviologen (MV/sup 2 +/) were investigated in homogeneous acetonitrile-water (4/1 v/v) mixture. In the N-methylphenothiazine-MV/sup 2 +/ system, the fluorescence quenching reaction was not affected by the addition of neutral salts, whereas the yield of viologen cation radical was greatly improved when some neutral salts having hydrophobic long alkyl chains were added in the solution. The well-known micellar effect was excluded since no preaggregation was found either between salts or between salt and reactant. The increased charge separation yield in the presence of neutral salts was well explained by the suppression of the backelectron-transfer reaction within the geminate ion pair owing to changes in solvation. The effect is discussed with two different and recently developed treatments, (i) solvent friction and (ii) solvation mode.

• Research Organization: Tokyo Institute of Technology, Yokohama, Japan
• OSTI ID: 7005447
• Journal Information: J. Phys. Chem.; (United States), Vol. 90:22
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
BIPYRIDINES
EXCITED STATES
PHOTOCHEMISTRY
RADIATIONLESS DECAY
PHENOTHIAZINES
ACETONITRILE
ELECTRON TRANSFER
EXPERIMENTAL DATA
FLUORESCENCE
WATER
AZINES
CHEMISTRY
DATA
DE-EXCITATION
ENERGY LEVELS
ENERGY TRANSFER
ENERGY-LEVEL TRANSITIONS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
INFORMATION
LUMINESCENCE
NITRILES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
OXYGEN COMPOUNDS
PYRIDINES
400500* - Photochemistry