Properties of Radical Cations Generated by the Pulse Radiolysis of 1,ω-Bis(diarylethenyl)alkanes. Trapping of Distonic 1,4-Radical Cation by Molecular Dioxygen

1994 ◽  
Vol 23 (1) ◽  
pp. 149-152 ◽  
Author(s):  
Toshiyuki Tamai ◽  
Kazuhiko Mizuno ◽  
Isao Hashida ◽  
Yoshio Otsuji ◽  
Akito Ishida ◽  
...  
Keyword(s):  
Radical Cation ◽  
Pulse Radiolysis ◽  
Radical Cations

Electron n-doping of a highly electron-deficient chlorinated benzodifurandione-based oligophenylene vinylene polymer using benzyl viologen radical cations

2021 ◽  
Author(s):  
Teck Lip Dexter Tam ◽  
Albertus Denny Handoko ◽  
Ting Ting Lin ◽  
Jianwei Xu
Keyword(s):  
Radical Cation ◽  
Radical Cations ◽  
Benzyl Viologen ◽  
Electron Doping ◽  
N Doping ◽  
Polyphenylene Vinylene

Successful electron-doping of highly electron-deficient chlorinated benzodifurandione-based polyphenylene vinylene using viologen radical cation.

scholarly journals Pulse Radiolysis Studies of Solvent Radical Cations in Liquid 1,2-Dichloroethane

1988 ◽  
Vol 61 (9) ◽  
pp. 3055-3059 ◽  
Author(s):  
Takashi Sumiyoshi ◽  
Naoki Sugita ◽  
Kazuyuki Watanabe ◽  
Meiseki Katayama
Keyword(s):  
Pulse Radiolysis ◽  
Radical Cations

Radical cation formation during the adsorption of polycyclic aromatic hydrocarbons on platinum oxide

1973 ◽  
Vol 26 (1) ◽  
pp. 221 ◽  
Author(s):  
JL Garnett ◽  
KJ Nicol ◽  
A Rainis
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Radical Cation ◽  
Aromatic Hydrocarbons ◽  
Hyperfine Splitting ◽  
Radical Cations ◽  
Platinum Oxide ◽  
Adsorbed Species ◽  
Experimental Conditions ◽  
Polycyclic Aromatic

Experimental conditions are reported for resolving the hyperfine splitting of e.p.r. spectra obtained from the interaction of polycyclic aromatic hydrocarbons with platinum oxide. By contrast with earlier interpretations where only a singlet was obtained even with perylene, the present results indicate that the adsorbed species are radical cations.

Phenylalanine: Its ˙OH and SO4˙⁻-Induced Oxidation and Decarboxylation. A Pulse Radiolysis and Product Analysis Study

1993 ◽  
Vol 48 (6) ◽  
pp. 761-770 ◽  
Author(s):  
Degui Wang ◽  
Heinz-Peter Schuchmann ◽  
Clemens von Sonntag
Keyword(s):  
Radical Cation ◽  
Pulse Radiolysis ◽  
Side Reactions ◽  
Intramolecular Electron Transfer ◽  
Oh Radical ◽  
Product Analysis ◽  
Water Elimination ◽  
Deprotonation Reaction ◽  
Type Radical ◽  
Radical Yield

Phenylamine has been oxidized by radiolytically generated hydroxyl and sulfate radicals, the ensuing intermediates and their reactions have been studied by pulse radiolysis and product analysis in the absence and presence of oxidants such as Fe(CN)63- and O2. Upon OH radical attack, hydroxycyclohexadienyl-type radicals are mainly formed while Η-abstraction reactions can be neglected. In the presence of Fe(CN)63- these radicals are for the most part oxidized to the corresponding tyrosines (80%), except for the ipso-OH-adduct radicals (≈ 20%). It is concluded that ˙OH-addition is almost random, but with a slight avoidance of the metaposition relative to the ortho-, para- and ipso-positions. Oxygen adds reversibly to the OH-adduct radicals (kf = 1.8 × 108 dm3 mol-1 s-1, kr = 5.4 × 104 s-1). In this case, tyrosine formation occurs by HO2˙-elimination. However, due to side reactions, tyrosine formation only reaches 52% of the OH radical yield. The tyrosine yield drops to 10% in the absence of an oxidant.Upon SO4˙⁻-attack, decarboxylation becomes a major process (33% of SO4˙⁻) alongside the production of tyrosines (43%). Here, with Fe(CN)63- as the oxidant the formation of p-Tyr (18.5%) and m-Tyr (16.5%) is preferred over o-Tyr formation (8.5%). It is believed that in analogy to other systems a radical cation is formed immediately upon SO4˙⁻-attack which either reacts with water under the formation of hydroxycyclohexadienyl-type (“OH-adduct”) radicals, or decarboxylates after intramolecular electron transfer. The radical cation can also arise indirectly through H+-catalysed water elimination from the ˙OH-adduct radicals. At pH 2 and a dose rate of 0.0046 Gy s-1 CO2 formation matches the OH radical yield when ˙OH is the attacking radical. Below pH 2, G(CO2) decreases with falling pH. This indicates the occurrence of another, unimolecular, pathway under these conditions competing effectively with decarboxylation. This appears to be a relatively slow deprotonation reaction of the carboxylprotonated phenylalanine radical cation which gives rise to the benzyl-type radical.

Radikalionen, 61 [1, 2]Dialkylamino-substituierte Acetylene und Allene:Ionisation, Oxidation und AlCl3-katalysierte Wasserstoffübertragung / Radical Ions, 61 [1, 2]Dialkylamino-substituted Acetylenes and Allenes:Ionisation, Oxidation and AlCl3-Catalyzed Hydrogen Transfer

1984 ◽  
Vol 39 (6) ◽  
pp. 763-770 ◽  
Author(s):  
Hans Bock ◽  
Wolfgang Kaim ◽  
Mitsuo Kira ◽  
Louis Réné ◽  
Heinz-Günther Viehe
Keyword(s):  
Radical Cation ◽  
Hydrogen Transfer ◽  
Radical Cations ◽  
Esr Spectra ◽  
Ionization Potentials ◽  
Radical Ions ◽  
Substituted Acetylenes

AbstractThe photoelectron (PE) spectra of bis(dialkylamino) acetylenes R2N-C≡C-NR2 and of tetrakis(dialkylamino) allenes (R2N)2C=C=C(NR2)2 with R = CH3, C2H5 exhibit characteristic ionization patterns which are assigned to π radical cation states of the two molecular halves twisted against each other. The low first ionization potentials between 7.0 eV and 7.7 eV stimu­lated attempts to oxidize using AlCl3 in H2CCl2 or D2CCl2. The hyperfine structured ESR spectra observed can be unequivocally assigned to the ethylene radical cations R2N-HC=CH -NR2˙⊕ which are formed from the obviously non-persistent species R2N-C≡C-NR2˙⊕ via a hydrogen transfer. During the oxidation of the dialkylamino-substituted allenes no paramagnetic intermedi­ates could be detected, presumably due to a rapid dimerisation of the allene radical cation (R2N)2C=C=C(NR2)2˙⊕.

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