TY - JOUR
T1 - Efficient photoinduced electron transfer between c60 and tetrathiafulvalenes studied by nanosecond laser photolysis
AU - Alam, Maksudul M.
AU - Watanabe, Akira
AU - Osamu, Ito
N1 - Funding Information:
This work was partially supported by Grants-in-Aid on Priority-Area-Research on "Photoreaction Dynamics" (No. 08218207) and "Functionally Graded Material" (No. 0824326) from the Ministry of Education, Science, Sports and Culture. The authors wish to thank Professor H. Kokubun (Aomori University) for useful comments.
PY - 1997/4
Y1 - 1997/4
N2 - Photoinduced electron transfer between C60 and tetrathiafulvalene (TTF) or bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) in polar and non-polar solvents and their mixtures was investigated by nanosecond laser photolysis/transient absorption spectroscopy in the visible and near-IR regions. The transient absorption bands of the C60 triplet (TC*60) observed in polar solvents decay on addition of TTF (or BEDT-TTF), accompanied by the appearance of the transient absorption bands of C.-60. The yields of C.-60 are decreased on addition of O2, revealing that about 10% of C.-60 is produced via the singlet state at donor concentrations of less than 5 × 10-3 M. In benzene, the quenching of TC*60 without the appearance of C.-60 within the nanosecond laser pulse is attributed to collisional quenching. The quantum efficiencies of C.-60 formation via TC*60, which were evaluated from the initial [TC*60] and maximal [C.-60] values, vary with the donor ability and solvent polarity. The forward electron transfer rate constants were evaluated from the decay rates of TC*60 (or the rise rates of C.-60) after multiplying by the quantum efficiencies. The back electron transfer rates are slowed down in polar solvents.
AB - Photoinduced electron transfer between C60 and tetrathiafulvalene (TTF) or bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) in polar and non-polar solvents and their mixtures was investigated by nanosecond laser photolysis/transient absorption spectroscopy in the visible and near-IR regions. The transient absorption bands of the C60 triplet (TC*60) observed in polar solvents decay on addition of TTF (or BEDT-TTF), accompanied by the appearance of the transient absorption bands of C.-60. The yields of C.-60 are decreased on addition of O2, revealing that about 10% of C.-60 is produced via the singlet state at donor concentrations of less than 5 × 10-3 M. In benzene, the quenching of TC*60 without the appearance of C.-60 within the nanosecond laser pulse is attributed to collisional quenching. The quantum efficiencies of C.-60 formation via TC*60, which were evaluated from the initial [TC*60] and maximal [C.-60] values, vary with the donor ability and solvent polarity. The forward electron transfer rate constants were evaluated from the decay rates of TC*60 (or the rise rates of C.-60) after multiplying by the quantum efficiencies. The back electron transfer rates are slowed down in polar solvents.
KW - C
KW - Electron transfer
KW - Laser photolysis
KW - Tetrathiafulvalene
UR - http://www.scopus.com/inward/record.url?scp=0031115788&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031115788&partnerID=8YFLogxK
U2 - 10.1016/S1010-6030(97)00017-8
DO - 10.1016/S1010-6030(97)00017-8
M3 - Article
AN - SCOPUS:0031115788
VL - 104
SP - 59
EP - 64
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
SN - 1010-6030
IS - 1-3
ER -