Regioselective S—O vs. C—O bond cleavage in sulfenate ester radical anions

2005 ◽  
Vol 83 (9) ◽  
pp. 1473-1482 ◽  
Author(s):  
Donald LB Stringle ◽  
Mark S Workentin
Keyword(s):  
Electron Transfer ◽  
Bond Cleavage ◽  
Electrochemical Techniques ◽  
Radical Anions ◽  
Peak Potential ◽  
Dissociative Mechanism ◽  
Dissociative Electron Transfer ◽  
Controlled Potential Electrolysis ◽  
Controlled Potential ◽  
Singly Occupied Molecular Orbitals

The electron transfer (ET) reduction of benzyl benzenesulfenate ester (1) and tert-butyl benzenesulfenate ester (2) was investigated using electrochemical techniques. Analysis of the cyclic voltammetry of each compound suggests that the ET reduction proceeds via a stepwise dissociative mechanism. The voltammograms of 1 are similar to those of diaryl disulfides and it was found through controlled potential electrolysis (CPE) product studies that ET reduction leads to S—O bond cleavage. The voltammograms of 2 are dramatically different with a sharper dissociative wave occurring at a more negative peak potential. CPE experiments indicate products that result from ET leading to C—O bond cleavage in this case. DFT calculations of the singly occupied molecular orbitals (SOMOs) of 1 and 2 were performed and offer a rationale for the different reactivity of the two radical anions.Key words: sulfenate esters, dissociative electron transfer, electrochemistry, radical anions.

scholarly journals Integrated Study of the Dinitrobenzene Electroreduction Mechanism by Electroanalytical and Computational Methods

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Andrey S. Mendkovich ◽  
Mikhail A. Syroeshkin ◽  
Ludmila V. Mikhalchenko ◽  
Mikhail N. Mikhailov ◽  
Alexander I. Rusakov ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Quantum Chemical ◽  
Bond Cleavage ◽  
Digital Simulation ◽  
Radical Anions ◽  
Theoretical Methods ◽  
Controlled Potential Electrolysis ◽  
Proton Donors ◽  
Controlled Potential ◽  
Integrated Study

Electroreduction of 1,2-, 1,3-, and 1,4-dinitrobenzenes in DMF has been investigated by a set of experimental (cyclic voltammetry, chronoamperometry, and controlled potential electrolysis) and theoretical methods (digital simulation and quantum chemical calculations). The transformation of only one nitro group is observed in the presence of proton donors. The process selectivity is provided by reactions of radical anions' intermediate products. The key reactions here are protonation of radical anions of nitrosonitrobenzenes and N-O bond cleavage in radical anions of N-(nitrophenyl)-hydroxylamines.

Paramagnetic organometallic molecules. XIV. Ion-pair and steric effects in dissociative electron transfer reactions of metal cluster carbonyl radical anions

1983 ◽  
Vol 36 (3) ◽  
pp. 441 ◽  
Author(s):  
CM Kirk ◽  
BM Peake ◽  
BH Robinson ◽  
J Simpson
Keyword(s):  
Electron Transfer ◽  
Metal Cluster ◽  
Metal Carbonyl ◽  
Electron Attachment ◽  
Transfer Reactions ◽  
Organic Radical ◽  
Radical Anions ◽  
Dissociative Electron Attachment ◽  
Dissociative Electron Transfer ◽  
Electron Transfer Reactions

An investigation of electron attachment reactions of cluster metal carbonyls is presented. In general, alkyl and organometallic halides react rapidly with metal carbonyl cluster radical anions at ambient temperatures to give the neutral cluster molecule. Halide ion and alkyl or organometallic radicals are also produced, which indicate that these are dissociative electron attachment reactions analogous to those of organic radical anions. The rate of dissociative electron attachment in reactions of PhCCo3(CO)9- was found to depend on the R-X bond energy, the size of the alkyl group and the nature of the counter-ion. In particular, (Ph3P)2N+ retarded some electron transfer reactions to the extent that the bimolecular decay of PhCCo3(CO)9- effectively competed with the electron transfer process in determining the reaction path.

Electrochemical investigation of reduction of mercury complexes of 2-aminocyclopentene-1-dithiocarboxylic acid and some of its derivatives at mercury electrodes

1996 ◽  
Vol 74 (1) ◽  
pp. 95-102 ◽  
Author(s):  
A. Safavi ◽  
M. B. Gholivand
Keyword(s):  
Electrochemical Techniques ◽  
Mercury Electrode ◽  
Elemental Mercury ◽  
Redox Processes ◽  
Electrochemical Investigation ◽  
Controlled Potential Electrolysis ◽  
Mercury Complexes ◽  
Controlled Potential ◽  
Mercury Electrodes ◽  
Complementary Study

Electrochemical techniques of polarography, cyclic voltammetry, and controlled potential electrolysis at mercury electrodes have permitted a detailed investigation of the reduction reactions associated with mercury 2-aminocyclopentene dithiocarboxylate complexes, Hg(ACD)2, in dimethyl sulphoxide (DMSO). As a complementary study, the electrochemistry of the ligands themselves was investigated in DMSO solutions and at mercury electrodes. The lability of mercury(II) complexes and their rapid interaction with elemental mercury strongly influence the nature of the redox processes observed at mercury electrodes. Reduction of Hg(ACD)2 at a mercury electrode occurs in an overall two-electron step as:[Formula: see text]although mercury(I) is implicated as an intermediate. Key words: reduction, electrochemical techniques, mercury complexes.

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