Electron donor-acceptor quenching and photoinduced electron transfer for coumarin dyes. Technical report, 1 January-31 October 1982

Technical Report · Mon Oct 31 00:00:00 EST 1983

OSTI ID:5104966

Jones, G II; Griffin, S F; Choi, C; Bergmark, W R

The fluorescence of 7-aminocoumarins is quenched by a variety of organic electron donors or acceptors in acetonitrile. In general, donors with half-wave oxidation potentials less positive than 1.0 V vs SCE and acceptors with reduction potentials less negative than -1.5 V vs SCE are candidates for diffusion limited quenching of coumarin singlet states. Profiles of quenching rates are consistent with calculated free energies for electron transfer between excited coumarins and donors or acceptors. In flash photolysis experiments electron transfer for several dyes and quenchers (e.g., methyl viologen) is demonstrated. Relatively low yields of net electron transfer are consistently obtained due to inefficient ionic photodissociation via singlet quenching or a low yield of more photoactive coumarin triplets. Electrochemical properties of the coumarins have been investigated by cyclic voltammetry with the indications of reversible oxidation and irreversible reduction as important processes.

• Research Organization: Boston Univ., MA (USA). Dept. of Chemistry
• OSTI ID: 5104966
• Report Number(s): AD-A-136345/6; TR-3
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACETONITRILE
PHOTOCHEMISTRY
COUMARINS
ELECTROCHEMISTRY
PHOTOLYSIS
ABSORPTION SPECTRA
DYES
ELECTRON TRANSFER
FLUORESCENCE
LASERS
PHOTOCHEMICAL REACTIONS
QUENCHING
TRIPLETS
VOLTAMETRY
ANTICOAGULANTS
CHEMICAL REACTIONS
CHEMISTRY
DECOMPOSITION
DRUGS
HEMATOLOGIC AGENTS
LUMINESCENCE
MULTIPLETS
NITRILES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
SPECTRA
400500* - Photochemistry