Photoreduction Of Methylviologen In The Interlayers Of Some Layered Titanates And Niobates

1991 ◽  
Vol 233 ◽  
Author(s):  
Teruyuki Nakato ◽  
Yoshiyuki Sugahara ◽  
Kazuyuki kuroda ◽  
Chuzo Kato
Keyword(s):  
Electron Transfer ◽  
Uv Irradiation ◽  
Photoinduced Electron Transfer ◽  
Radical Cations ◽  
Intercalation Compounds ◽  
Layered Oxides ◽  
Semiconducting Oxides ◽  
The Difference

ABSTRACTMethylviologen dication was intercalated to some layered semiconducting oxides, and the photoinduced electron transfer between the hosts and the guest was investigated. K4 Nb6O17, H2 Ti4O9, and HTiNbO5 were used as the layered oxides. The arrangements of methylviologen in the interlayers were deduced from the XRD results. UV irradiation of the intercalation compounds caused electron transfer from the hosts to the guest to form methylviologen radical cations. The radical cations were stable within a few minutes even in the presence of oxygen, and the decaying rates altered with the hosts. The difference was discussed on the basis of the structure of the intercalation compounds.

scholarly journals Electron self-exchange activation parameters of diethyl sulfide and tetrahydrothiophene

2013 ◽  
Vol 9 ◽  
pp. 1448-1454
Author(s):  
Martin Goez ◽  
Martin Vogtherr
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Nuclear Polarization ◽  
Activation Barrier ◽  
Activation Parameters ◽  
Radical Cations ◽  
Free Energies ◽  
Time Resolved ◽  
Diethyl Sulfide ◽  
Chemically Induced

Electron transfer between the title compounds and their radical cations, which were generated by photoinduced electron transfer from the sulfides to excited 2,4,6-triphenylpyrylium cations, was investigated by time-resolved measurements of chemically induced dynamic nuclear polarization (CIDNP) in acetonitrile. The strongly negative activation entropies provide evidence for an associative–dissociative electron exchange involving dimeric radical cations. Despite this mechanistic complication, the free energies of activation were found to be well reproduced by the Marcus theory of electron transfer, with the activation barrier still dominated by solvent reorganization.

Regio- and stereoselective functionalization of electron-deficient alkenes by organosilicon compounds via photoinduced electron transfer

2003 ◽  
Vol 75 (8) ◽  
pp. 1049-1054 ◽  
Author(s):  
K. Mizuno ◽  
T. Hayamizu ◽  
Hajime Maeda
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Radical Cations ◽  
Reactive Intermediates ◽  
Radical Anions ◽  
Organosilicon Compounds ◽  
Allylic Silanes ◽  
Carbon Radicals

Regio- and stereoselective photoallylation of electron-deficient alkenes by use of allylic silanes via photoinduced electron transfer has been described. Similar photoinduced  functionalization reactions such as arylmethylation, alkylation, and silylation can be achieved by using a variety of organosilicon compounds. These photoreactions proceed via radical cations of organosilicon compounds and radical anions of electron-deficient alkenes as reactive intermediates. The key step of the photoreactions is the attack of carbon radicals, which are generated from the radical cations of organosilicon compounds, on the radical anions of alkenes. The mechanism of the regio- and stereoselective photofunctionalization is discussed.

Photoinduced electron-transfer reactions. The radical cations of methano-bridged paracyclophanes

1983 ◽  
Vol 105 (2) ◽  
pp. 153-157 ◽  
Author(s):  
Heinz D. Roth ◽  
Marcia L. Manion Schilling ◽  
Richard S. Hutton ◽  
Elizabeth A. Truesdale
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Radical Cations ◽  
Transfer Reactions ◽  
Electron Transfer Reactions

Photoinduced electron transfer C—C bond cleavage reactions; oxidations and isomerizations

1984 ◽  
Vol 62 (3) ◽  
pp. 424-436 ◽  
Author(s):  
L. W. Reichel ◽  
G. W. Griffin ◽  
A. J. Muller ◽  
P. K. Das ◽  
Seyhan N. Ege
Keyword(s):  
Electron Transfer ◽  
Photoinduced Electron Transfer ◽  
Flash Photolysis ◽  
Laser Flash Photolysis ◽  
Bond Cleavage ◽  
Radical Cations ◽  
Laser Flash ◽  
Time Resolved ◽  
Fragmentation Reactions ◽  
Oxidative Products

We have shown that radical cations generated by photoinduced electron transfer (ET) in 1,2-diarylethanes, aryl pinacols, and their derivatives undergo fragmentation reactions. In the presence of oxygen oxidative products are obtained. Time-resolved laser flash photolysis and other ancillary techniques have permitted us to define the mechanisms of certain oxidative processes observed.

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