ChemInform Abstract: Picosecond Dynamics of Stilbene-Olefin Contact and Solvent-Separated Radical Ion Pairs: Role of Electron Transfer and Radical Ion Pair Diffusion

ChemInform ◽  
2010 ◽  
Vol 24 (36) ◽  
pp. no-no
Author(s):  
K. S. PETERS ◽  
J. LEE
Keyword(s):  
2003 ◽  
Vol 81 (6) ◽  
pp. 789-798 ◽  
Author(s):  
Guilford Jones II ◽  
Xiaochun Wang ◽  
Jingqiu Hu

The electron-transfer photochemistry of rhodamine 6G thiocyanate ion pairs has been investigated. For dye in a low polarity solvent, such as ethyl acetate, the emission of rhodamine 6G is significantly quenched by thiocyanate counterions. Laser photolysis of rhodamine 6G and thiocyanate in ethyl acetate was studied in detail with the identification of the reduced rhodamine 6G radical species (λmax = 410 nm). The growth and decay of the R6G radical could be accounted for in part by a mechanism involving initial formation of dye triplet followed by electron transfer which provides a triplet radical-pair state on a µs timescale.Key words: electron transfer, ion pair, rhodamine 6G, triplet state.


1978 ◽  
Vol 31 (4) ◽  
pp. 835 ◽  
Author(s):  
GE Gream ◽  
MH Laffer ◽  
AK Serelis

The synthesis and solvolytic behaviour (in buffered acetic acid) of cis- and trans-9-t-butylspiro[4,5]-dec-6-yl p-toluenesulfonate (5) and (6) are described. The two compounds solvolyse with anchimeric assistance and undergo ring expansion with complete stereospecificity; the cis- and trans-esters yield trans- and cis-2-t-butyl-9-decalyl cation (8) and (7), respectively. To account for the stereospecificity, it is proposed that (6) must solvolyse through a boat conformation of the six-membered ring. Ring contraction (c. 8%), with the formation of the 1-(3'-t-butylcyclopentyl)cyclopentyl cation (presumably trans (36)), also takes place in the acetolysis of (6). ��� The possible role of ion-pairs in the reactions of (5) and (6) is examined. It is concluded that the anion in an ion-pair might be involved in olefin formation only when it (the anion) is ideally located for proton abstraction in the initially formed ion-pair (or that formed by conformational interconversion of the cationic moiety).


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