Photoinduced electron transfer from enol silyl ethers to quinone. Part 1. Pronounced effects of solvent polarity and added salt on the formation of α-enones

1996 ◽  
pp. 1623-1632 ◽  
Author(s):  
T. Michael Bockman ◽  
D. Shukla ◽  
Jay K. Kochi
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Solvent Polarity ◽  
Silyl Ethers ◽  
Enol Silyl Ethers ◽  
Added Salt

Efficient photoinduced electron transfer between C60/C70 and zinc octaethylporphyrin studied by nanosecond laser photolysis method

2000 ◽  
Vol 04 (06) ◽  
pp. 591-598 ◽  
Author(s):  
MOHAMED E. EL-KHOULY ◽  
MAMORU FUJITSUKA ◽  
OSAMU ITO
Keyword(s):  
Electron Transfer ◽  
Rate Constants ◽  
Photoinduced Electron Transfer ◽  
Transfer Rate ◽  
Transient Absorption ◽  
Laser Light ◽  
Solvent Polarity ◽  
Nanosecond Laser ◽  
Electron Transfer Rate ◽  
Absorption Bands

Photoinduced electron-transfer processes between C 60 or C 70 and zinc octaethylporphyrin ( ZnOEP ) have been studied in polar solvents with the nanosecond laser flash photolysis method, observing the transient absorption spectra in the visible and near-IR regions. By the predominant excitation of ZnOEP with 532 nm laser light the transient absorption bands of 3 ZnOEP * decayed, accompanied by the appearance of the transient absorption bands of [Formula: see text] and [Formula: see text]. By the predominant excitation of C 60 and C 70 with 610 nm laser light the decays of [Formula: see text] and [Formula: see text] were observed, accompanied by the appearance of [Formula: see text] and [Formula: see text]. The electron transfer rate constants (k et ) and the quantum yields (Φ et ) of [Formula: see text] and [Formula: see text] formation via 3 ZnOEP * and [Formula: see text] or [Formula: see text] have been evaluated. These values increase with the solvent polarity; in polar benzonitrile these values are higher than for other porphyrins such as zinc tetraphenylporphyrin. The back electron transfer rate constants were evaluated from the decays of [Formula: see text] and [Formula: see text], which also show a solvent polarity dependence.

Photoalkylation of 10-Alkylacridinium Ion via a Charge-Shift Type of Photoinduced Electron Transfer Controlled by Solvent Polarity

2001 ◽  
Vol 123 (35) ◽  
pp. 8459-8467 ◽  
Author(s):  
Shunichi Fukuzumi ◽  
Kei Ohkubo ◽  
Tomoyoshi Suenobu ◽  
Kouta Kato ◽  
Mamoru Fujitsuka ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Solvent Polarity ◽  
Shift Type ◽  
A Charge ◽  
Charge Shift

Fluorescent PET (photoinduced electron transfer) indicators for solvent polarity with quasi-step functional response

1991 ◽  
Vol 32 (3) ◽  
pp. 425-428 ◽  
Author(s):  
Richard A. Bissell ◽  
A.Prasanna de Silva ◽  
W. Thilak ◽  
M.L. Fernando ◽  
Suram T. Patuwathavithana ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Functional Response ◽  
Photoinduced Electron Transfer ◽  
Solvent Polarity

Photoinduced Electron Transfer Processes in Rotaxanes Containing [60]Fullerene and Ferrocene: Effect of Axle Charge on Light-Induced Molecular Motion

2006 ◽  
Vol 59 (3) ◽  
pp. 186 ◽  
Author(s):  
Atula S. D. Sandanayaka ◽  
Hisahiro Sasabe ◽  
Yasuyuki Araki ◽  
Nobuhiro Kihara ◽  
Yoshio Furusho ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Transient Absorption ◽  
Solvent Polarity ◽  
Orbital Method ◽  
Time Resolved ◽  
Transfer Processes ◽  
Recombination Processes ◽  
Electron Transfer Processes ◽  
Absorption Measurements

Two rotaxanes containing [60]fullerene (C60) as pendants on a crown-ether necklace, to which ferrocene (Fc) as axle stoppers were added, have been synthesized. One rotaxane has an ammonium cation in the centre of the axle (C60;Fc)Rot+ and the other has a neutral axle (C60;Fc)Rot. Optimized structures, calculated using a molecular orbital method, suggest that in the ground states (C60;Fc)Rot+ has a shorter distance between C60 and Fc than that of (C60;Fc)Rot. In both rotaxanes, efficient intra-rotaxane photoinduced electron-transfer processes have been observed by the selective excitation of C60 which acts as a photosensitized electron acceptor. The rates and efficiencies of the charge-separation and charge-recombination processes were evaluated by time-resolved fluorescence and transient absorption measurements with changing solvent polarity. From the different kinetic parameters between (C60;Fc)Rot+ and (C60;Fc)Rot, the light-induced molecular motions of these rotaxanes in the excited states and charge-separated states were separately revealed.

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