Free electron transfer from several phenols to radical cations of non-polar solvents

2000 ◽  
Vol 2 (21) ◽  
pp. 4947-4955 ◽  
Author(s):  
Mahalaxmi R. Ganapathi ◽  
Ralf Hermann ◽  
Sergei Naumov ◽  
Ortwin Brede
Keyword(s):  
Electron Transfer ◽  
Free Electron ◽  
Radical Cations ◽  
Polar Solvents

Free Electron Transfer from Xanthenyl- and Fluorenylsilanes (Me3or Ph3) to Parent Solvent Radical Cations:  Effects of Molecule Dynamics

2005 ◽  
Vol 109 (51) ◽  
pp. 11679-11686 ◽  
Author(s):  
Nikolaos Karakostas ◽  
Sergej Naumov ◽  
Michael G. Siskos ◽  
Antonios K. Zarkadis ◽  
Ralf Hermann ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Free Electron ◽  
Radical Cations ◽  
Molecule Dynamics

Free electron transfer mirrors rotational conformers of substituted aromatics: Reaction of benzyltrimethylsilanes with n-butyl chloride parent radical cations

2004 ◽  
Vol 6 (9) ◽  
pp. 2267 ◽  
Author(s):  
Ortwin Brede ◽  
Ralf Hermann ◽  
Sergej Naumov ◽  
Antonios K. Zarkadis ◽  
Gerasimos P. Perdikomatis ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Free Electron ◽  
Radical Cations ◽  
Butyl Chloride

Diphenol radical cations and semiquinone radicals as direct products of the free electron transfer from catechol, resorcinol and hydroquinone to parent solvent radical cations

2002 ◽  
Vol 4 (20) ◽  
pp. 5096-5104 ◽  
Author(s):  
Ortwin Brede ◽  
Sudhir Kapoor ◽  
Tulsi Mukherjee ◽  
Ralf Hermann ◽  
Sergej Naumov
Keyword(s):  
Electron Transfer ◽  
Free Electron ◽  
Radical Cations ◽  
Direct Products ◽  
Semiquinone Radicals

Ionization of Aniline and ItsN-methyl andN-phenyl Substituted Derivatives by (Free) Electron Transfer ton-butyl Chloride Parent Radical Cations

2005 ◽  
Vol 109 (21) ◽  
pp. 4690-4696 ◽  
Author(s):  
Andrej Maroz ◽  
Ralf Hermann ◽  
Sergej Naumov ◽  
Ortwin Brede
Keyword(s):  
Electron Transfer ◽  
Free Electron ◽  
Radical Cations ◽  
Butyl Chloride

Discrete ionization of two different short-living conformers of selenophenol by rapid free electron transfer to solvent parent radical cations

2001 ◽  
Vol 350 (1-2) ◽  
pp. 165-172 ◽  
Author(s):  
O. Brede ◽  
R. Hermann ◽  
S. Naumov ◽  
H.S. Mahal
Keyword(s):  
Electron Transfer ◽  
Free Electron ◽  
Radical Cations

Thiol radical cations and thiyl radicals as direct products of the free electron transfer from aromatic thiols to n-butyl chloride radical cations

2000 ◽  
Vol 2 (6) ◽  
pp. 1213-1220 ◽  
Author(s):  
Ralf Hermann ◽  
Ghasi Ram Dey ◽  
Sergej Naumov ◽  
Ortwin Brede
Keyword(s):  
Electron Transfer ◽  
Free Electron ◽  
Radical Cations ◽  
Direct Products ◽  
Butyl Chloride ◽  
Thiyl Radicals ◽  
Aromatic Thiols

scholarly journals Electron transfer reaction and demetalation of phthalocyanines

2000 ◽  
Vol 2 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Jean Kossanyi ◽  
Driss Chahraoui
Keyword(s):  
Electron Transfer ◽  
Rate Constant ◽  
Transfer Reaction ◽  
Fluorescence Emission ◽  
Radical Cations ◽  
Electron Transfer Reaction ◽  
Electron Acceptors ◽  
Electron Donors ◽  
Polar Solvents ◽  
The One

An electron-transfer reaction takes place in the ground state between phthalocyanines (as electron-donors) and pyrylium cations (as electron-acceptors) in polar solvents, reaction which leads to the phthalocyanine radical-cations as evidenced by its absorption spectra identical to the one of the species formed by electrochemical oxidation.The fluorescence emission of the phthalocyanines is quenched by electron-acceptors (principally quinones). The free energy changeΔGCTof the electron-transfer reaction has been evaluated for each electron acceptor with a solvation energy of 0.14 eV in the case of dimethylformamide and 1.2 eV in that of dichloromethane. The rate constant of the quenching of the phthalocyanines singlet excited state by a series of electronacceptors is found to be of the order of1.2−1.5×1010L⋅mol-1s-1.Metalated phthalocyanines are demetalated in the dark by hydroxy-anthraquinones with a rate constant of the order of10−2L⋅mol-1s-1at 292K and which increases (up to7×10−2L⋅mol-1s-1at 349 K) with temperature. The activation energy of the demetalation reaction has been determined to be ca 30kJ⋅mol-1for 1,4-dihydroxyanthraquinone and 35kJ⋅mol-1for 1,2,4-trihydroxyanthraquinone.

Ionization of mercapto- and hydroxypyridines by free electron transfer to alkyl chloride parent radical cations

2005 ◽  
Vol 31 (1-3) ◽  
pp. 113-133 ◽  
Author(s):  
Devidas B Naik ◽  
Ralf Hermann ◽  
Tulsi Mukherjee ◽  
Sergej Naumov ◽  
Ortwin Brede
Keyword(s):  
Electron Transfer ◽  
Free Electron ◽  
Radical Cations ◽  
Alkyl Chloride

scholarly journals Spectral Probe for Electron Transfer and Addition Reactions of Azide Radicals with Substituted Quinoxalin-2-Ones in Aqueous Solutions

2021 ◽  
Vol 22 (2) ◽  
pp. 633
Author(s):  
Konrad Skotnicki ◽  
Slawomir Ostrowski ◽  
Jan Cz. Dobrowolski ◽  
Julio R. De la Fuente ◽  
Alvaro Cañete ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Aqueous Solutions ◽  
Absorption Spectra ◽  
Density Functional ◽  
Reduction Potential ◽  
Biological Significance ◽  
Radical Cations ◽  
Basis Sets ◽  
Double Bonds ◽  
Reduction Potentials

The azide radical (N3●) is one of the most important one-electron oxidants used extensively in radiation chemistry studies involving molecules of biological significance. Generally, it was assumed that N3● reacts in aqueous solutions only by electron transfer. However, there were several reports indicating the possibility of N3● addition in aqueous solutions to organic compounds containing double bonds. The main purpose of this study was to find an experimental approach that allows a clear assignment of the nature of obtained products either to its one-electron oxidation or its addition products. Radiolysis of water provides a convenient source of one-electron oxidizing radicals characterized by a very broad range of reduction potentials. Two inorganic radicals (SO4●−, CO3●−) and Tl2+ ions with the reduction potentials higher, and one radical (SCN)2●− with the reduction potential slightly lower than the reduction potential of N3● were selected as dominant electron-acceptors. Transient absorption spectra formed in their reactions with a series of quinoxalin-2-one derivatives were confronted with absorption spectra formed from reactions of N3● with the same series of compounds. Cases, in which the absorption spectra formed in reactions involving N3● differ from the absorption spectra formed in the reactions involving other one-electron oxidants, strongly indicate that N3● is involved in the other reaction channel such as addition to double bonds. Moreover, it was shown that high-rate constants of reactions of N3● with quinoxalin-2-ones do not ultimately prove that they are electron transfer reactions. The optimized structures of the radical cations (7-R-3-MeQ)●+, radicals (7-R-3-MeQ)● and N3● adducts at the C2 carbon atom in pyrazine moiety and their absorption spectra are reasonably well reproduced by density functional theory quantum mechanics calculations employing the ωB97XD functional combined with the Dunning’s aug-cc-pVTZ correlation-consistent polarized basis sets augmented with diffuse functions.

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