Kinetics of Intersystem Electron Transfer within Triplet Radical Ion Pairs on Silica Studied by Diffuse-Reflectance Laser Flash Photolysis. Bell-Shaped Energy Gap Dependence on the Surface

1995 ◽  
Vol 99 (4) ◽  
pp. 1267-1275 ◽  
Author(s):  
Peter P. Levin ◽  
Silvia M. B. Costa ◽  
L. F. Vieira Ferreira
1988 ◽  
Vol 66 (2) ◽  
pp. 319-324 ◽  
Author(s):  
R. J. DeVoe ◽  
M. R. V. Sahyun ◽  
Einhard Schmidt ◽  
N. Serpone ◽  
D. K. Sharma

We have studied the anthracene-sensitized photolyses of both diphenyliodonium and triphenylsulphonium salts in solution using both steady-state and laser flash photolysis techniques. Photoproducts, namely, phenylated anthracenes along with iodobenzene or diphenylsulphide, respectively, are obtained from both salts with quantum efficiencies of ca. 0.1 at 375 nm. We infer the intermediacy of diphenyliodo and triphenylsulphur radicals formed by single electron transfer from the singlet-excited anthracene. We have developed a quantitative model of this chemistry, and identify the principal sources of inefficiency as back electron transfer, which occurs at nearly the theoretically limiting rate, intersystem crossing from the initially formed sensitizer–'onium salt encounter complex, and in-cage radical recombination.


Biochemistry ◽  
1983 ◽  
Vol 22 (23) ◽  
pp. 5270-5279 ◽  
Author(s):  
Anjan Bhattacharyya ◽  
Gordon Tollin ◽  
Michael Davis ◽  
Dale E. Edmondson

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