Interconversion and rearrangement of radical cations. Part 2.1 Photoinduced electron transfer and electrochemical oxidation of 1,4-bis(methylene)cyclohexane

Author(s):  
H. J. P. de Lijser ◽  
Donald R. Arnold
2013 ◽  
Vol 9 ◽  
pp. 1448-1454
Author(s):  
Martin Goez ◽  
Martin Vogtherr

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.


1991 ◽  
Vol 233 ◽  
Author(s):  
Teruyuki Nakato ◽  
Yoshiyuki Sugahara ◽  
Kazuyuki kuroda ◽  
Chuzo Kato

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.


2003 ◽  
Vol 75 (8) ◽  
pp. 1049-1054 ◽  
Author(s):  
K. Mizuno ◽  
T. Hayamizu ◽  
Hajime Maeda

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.


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

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