Influence of the conjugate anion on the parameters of ESR spectra in radical cations of sterically hindered hydroquinones

1987 ◽  
Vol 22 (6) ◽  
pp. 706-709
Author(s):  
E. S. Klimov ◽  
G. A. Abakumov ◽  
O. Yu. Okhlobystin
Keyword(s):  
Radical Cations ◽  
Esr Spectra ◽  
Sterically Hindered

Od ESR spectra of cis-decalin radical cations in liquid and glassy solutions

1986 ◽  
Vol 127 (1) ◽  
pp. 97-100 ◽  
Author(s):  
V.I. Melekhov ◽  
O.A. Anisimov ◽  
A.V. Veselov ◽  
Yu.N. Molin
Keyword(s):  
Radical Cations ◽  
Esr Spectra

Esr spectra of some radical cations of fluorinated hydrocarbons

1969 ◽  
Vol 10 (10) ◽  
pp. 797-800 ◽  
Author(s):  
P.H.H. Fischer ◽  
H. Zimmermann
Keyword(s):  
Radical Cations ◽  
Esr Spectra ◽  
Fluorinated Hydrocarbons

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˙⊕.

ESR Studies on 205Tl Hyperfine Couplings in the Radical Cations of Tl(III)Porphyrins

1974 ◽  
Vol 29 (12) ◽  
pp. 1827-1833 ◽  
Author(s):  
Chr. Mengersen ◽  
J. Subramanian ◽  
J.-H. Fuhrhop ◽  
K. M. Smith
Keyword(s):  
Spin Density ◽  
Spin Polarization ◽  
Radical Cations ◽  
Esr Spectra ◽  
Cation Radicals ◽  
Bilinear Relation ◽  
Tetraphenyl Porphyrin ◽  
Pi Orbitals ◽  
Spin Densities ◽  
Hyperfine Couplings

The isotropic 205Tl hyperfine couplings obtained from the ESR spectra of the radical cations of Tl (III) meso tetraphenyl porphyrin (TPP), octaethyl porphyrin (OEP) and octaethyl chlorin (OEC) are reported. The radical cations were generated by electrooxidation in dichloromethane as solvent. A Karplus-Fraenkel type bilinear relation is used to interpret the 205Tl couplings, taking into account the sigma-pi spin polarization of Tl -N bonds by the spin density at the nitrogen atoms in the ligand as well as the direct pi interaction of the orbitals of Tl with the pi orbitals of the ligand. It is shown that for the cation radicals of Tl porphyrins, both these mechanisms contribute to the Tl couplings whereas for the cation radicals of Co- and Zn-porphyrins the sigma-pi polarization alone is sufficient to account for the metal hyperfine couplings. It is suggested that Tl-hyperfine couplings can be used to estimate the nitrogen spin densities of porphyrin radical systems when the nitrogen splittings are not resolved in the ESR spectra.

Metall-π-Komplexe yon Benzolderivaten, XIII Bis(methylthio-η-beiizol)chrom(0) Darstellung und Einsatz als zweizähniger Chelatligand/ Metal-π Complexes of Benzene Derivatives, XIII Bis(methylthio-η-benzene)chromium(0) Preparation and Function as a Bidentate Chelating Ligand

1981 ◽  
Vol 36 (1) ◽  
pp. 94-101 ◽  
Author(s):  
Helmut Burdorf ◽  
Christoph Eischenbroich
Keyword(s):  
Nmr Spectra ◽  
Room Temperature ◽  
Radical Cations ◽  
Esr Spectra ◽  
Benzene Derivatives ◽  
Consecutive Reaction ◽  
H Nmr ◽  
Chelating Ligand ◽  
And Function ◽  
C Nmr

Abstract The thioanisole-π-complexes (methylthio-η-benzene)-(η-benzene)-chromium (2) and bis(methylthio-η-benzene)chromium (3) have been prepared via lithiation of bis(η-benzene)-chromium and consecutive reaction with dimethyldisulfide. 1H NMR and 13C NMR spectra of 2 and 3 as well as ESR-spectra of the corresponding radical cations 2.+ and 3.+ were recorded and analyzed. In contrast to C(η-arene)-Si and C(η-arene)-P bonds, C(y-arene)-S bonds are stable to solvolysis. With (norbornadiene)tetracarbonylmolybdenum, 3 readily forms [bis(methylthio-η-benzene)chromium]tetracarbonylmolybdenum (6) wherein 3 functions as a chelating ligand. 1H and 13C NMR evidence suggests, that at room temperature 6 undergoes rapid conformational interconversions.

ChemInform Abstract: ESR SPECTRA OF RADICAL CATIONS RELATED TO 1,3,5-TRIHYDROXYBENZENE(PHLOROGLUCINOL)

1977 ◽  
Vol 8 (49) ◽  
Author(s):  
W. T. DIXON ◽  
D. MURPHY
Keyword(s):  
Radical Cations ◽  
Esr Spectra

One-Electron Oxidation of Sterically Hindered Amines to Nitroxyl Radicals:  Intermediate Amine Radical Cations, Aminyl, α-Aminoalkyl, and Aminylperoxyl Radicals

1998 ◽  
Vol 102 (9) ◽  
pp. 1457-1464 ◽  
Author(s):  
O. Brede ◽  
D. Beckert ◽  
C. Windolph ◽  
H. A. Göttinger
Keyword(s):  
Radical Cations ◽  
Nitroxyl Radicals ◽  
Sterically Hindered ◽  
Hindered Amines

ChemInform Abstract: The ESR Spectra of 1-Adamantylcyclobutadiene Radical Cations

ChemInform ◽  
1987 ◽  
Vol 18 (18) ◽  
Author(s):  
W. CHAN ◽  
J. L. COURTNEIDGE ◽  
A. G. DAVIES ◽  
A. G. NEVILLE ◽  
J. C. EVANS ◽  
...  
Keyword(s):  
Radical Cations ◽  
Esr Spectra

Radical Cations of Trialkylamines:  ESR Spectra and Structures

1999 ◽  
Vol 64 (19) ◽  
pp. 6951-6959 ◽  
Author(s):  
Armin de Meijere ◽  
Vladimir Chaplinski ◽  
Fabian Gerson ◽  
Pascal Merstetter ◽  
Edwin Haselbach
Keyword(s):  
Radical Cations ◽  
Esr Spectra
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