Light-induced Electron Transfer Processes Research Articles

The distance dependence of electron transfer reactions: rate maxima and rapid rates at large reactant separations

It has been found that the dependences of the electronic coupling element and of the solvent reorganization energy on distance have important implications for intramolecular electron transfers and for the forward and back reaction rates and cage-escape yields in light-induced electron-transfer processes. An equation is presented for the net second order rate constant for bimolecular transfer. A derived difference in the optimum distance for the forward and back reactions is pointed out to have important implications for the formulation of steady-state quenching schemes and for the interpretation of cage-escape yields.

Kinetics of electron transfer in duroquinone-reconstituted reaction centers from photosynthetic bacteria

Reaction centers isolated from photosynthetic bacteria are of interest both as a model system for biochemical electron transfer and as a simple system for study of the primary photochemistry of photosynthesis. The light-induced electron-transfer processes in purple photosynthetic bacteria begin with excitation of a bacteriochlorophyll (Bchl) dimer with maximum absorbance at 870 nm (P870). A relatively stable charge-separated state, consisting of oxidized P870 and reduced ubiquinone (UQ), is reached in < 1 ns [ 1,2]. An earlier unstable state almost certainly consists of P870+ and reduced bacteriopheophytin (BPh) [3]. Ubiquinone extraction leads to an apparent loss of photochemical activity than can be recovered by addition of UQ or a variety of other quinones [4-71. Here, we report experiments on reaction centers reconstituted with duroquinone (DQ, 2,3,5,6tetramethylbenzoquinone). We have found that the quantum yield of formation of the state P870+DQis essentially 1.0. The temperature dependence of the recombination kinetics of this state are anomalous, with temperature-independent regions at both low and high temperatures.

Photochemical reactivity in organized assemblies. 18. Light-induced electron-transfer processes in anionic micelles: specific electrolyte effects on the quenching process

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotochemical reactivity in organized assemblies. 18. Light-induced electron-transfer processes in anionic micelles: specific electrolyte effects on the quenching processRussell H. Schmehl, Leonard G. Whitesell, and David G. WhittenCite this: J. Am. Chem. Soc. 1981, 103, 13, 3761–3764Publication Date (Print):July 1, 1981Publication History Published online1 May 2002Published inissue 1 July 1981https://doi.org/10.1021/ja00403a024RIGHTS & PERMISSIONSArticle Views112Altmetric-Citations37LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (549 KB) Get e-Alerts Get e-Alerts