Theory of solvent effects on the hyperfine splitting constants in ESR spectra of free radicals

1982 ◽  
Vol 86 (8) ◽  
pp. 1358-1365 ◽  
Author(s):  
Takehiro Abe ◽  
Shozo Tero-Kubota ◽  
Yusaku Ikegami
Keyword(s):  
Free Radicals ◽  
Solvent Effects ◽  
Hyperfine Splitting ◽  
Esr Spectra

scholarly journals Abnormal Hyperfine Splitting in the ESR Spectra of α,α,γ,γ-Tetraphenylallyl-type Organic Stable Free Radicals

1972 ◽  
Vol 45 (2) ◽  
pp. 371-375 ◽  
Author(s):  
Kohji Watanabe ◽  
Jun Yamauchi ◽  
Hiroaki Ohya-Nishiguchi ◽  
Yasuo Deguchi ◽  
Hideo Takaki
Keyword(s):  
Free Radicals ◽  
Hyperfine Splitting ◽  
Esr Spectra ◽  
Stable Free Radicals

Solvent effects of ESR spectra of neutral nitroxide free radicals

1979 ◽  
Vol 15 (3) ◽  
pp. 207-212 ◽  
Author(s):  
A. Rockenbauer ◽  
F. Tüdős ◽  
S.A. Abdel-Monem
Keyword(s):  
Free Radicals ◽  
Solvent Effects ◽  
Esr Spectra

ESR study of the structure and bonding situation in thiocyanatocopper(II) complexes with imidazole derivatives

1988 ◽  
Vol 53 (1) ◽  
pp. 56-60
Author(s):  
Anna Mašlejová ◽  
Reinhard Kirmse
Keyword(s):  
Unpaired Electron ◽  
Hyperfine Splitting ◽  
Esr Spectra ◽  
Ligand Field ◽  
Imidazole Derivatives ◽  
Bonding Parameters ◽  
Monomeric Complex ◽  
Structure And Bonding ◽  
Frozen Solutions ◽  
Planar Symmetry

ESR spectra of thianatocopper(II) complexes with imidazole derivatives were studied in ethanolic solutions at 295 and 123 K. Axialsymmetric spectra, attributed to the monomeric complex units, were obtained for the frozen solutions. The bonding parameters were interpreted by using calculated g, Cu-hyperfine, and 14N-ligand hyperfine splitting values. The Cu-N bond parameters indicate a considerable delocalization of the unpaired electron. The values of the isotropic Cu-hyperfine splitting suggest that the deviations from the planar symmetry of the CuN4 units are due to tetrahedral perturbation of the ligand field.

Association of radical anion with alkali cations. IV. ESR study of the 4-nitrobenzophenone radical anion

1980 ◽  
Vol 45 (2) ◽  
pp. 369-375 ◽  
Author(s):  
Stanislav Miertuš ◽  
Ondrej Kyseľ
Keyword(s):  
Hyperfine Splitting ◽  
Radical Anion ◽  
Esr Spectroscopy ◽  
Supporting Electrolyte ◽  
Esr Spectra ◽  
Proton Donor ◽  
Alkali Cations

The 4-nitrobenzophenone radical anion prepared by electrolysis was studied by ESR spectroscopy. On the basis of the interpretation of ESR spectra, the conformation of this system was estimated. The effect of the concentration of supporting electrolyte and of the presence of a proton-donor agent (C2H5OH) was examined. It is assumed that changes in hyperfine splitting constants are caused by association.

Solvent effects on the nitrogen and β-hydrogen hyperfine splitting constants of aminoxyl radicals obtained in spin trapping experiments

1982 ◽  
Vol 60 (21) ◽  
pp. 2725-2733 ◽  
Author(s):  
Edward G. Janzen ◽  
Gregory A. Coulter ◽  
Uwe M. Oehler ◽  
John P. Bergsma
Keyword(s):  
Linear Relationship ◽  
Solvent Effects ◽  
Hyperfine Splitting ◽  
Spin Trapping ◽  
Tert Butyl ◽  
Aminoxyl Radicals ◽  
Structural Significance

The nitrogen and β-hydrogen hyperfine splitting constants (hfsc) for phenyl, 4-nitrophenyl, 4-pyridyl, benzoyl, and trichloromethyl spin adducts of α-phenyl tert-butyl nitrone (PBN) as well as for the tert-butoxyl adduct of 5,5-dimethylpyrroline-N-oxide (DMPO) have been obtained as a function of solvent (30 solvents). A useful linear relationship between the β-H hfsc and the N-hfsc of each aminoxyl is found except for the benzoyl adduct of PBN. Some speculations regarding the structural significance of these correlations is presented.

Spin Label Study of Apomembranes and Purple Membranes

1993 ◽  
Vol 48 (5-6) ◽  
pp. 500-503
Author(s):  
Tzvetana R. Lazarova ◽  
Maya Y. Velitchkova
Keyword(s):  
Fatty Acids ◽  
Lipid Bilayer ◽  
Spin Label ◽  
Hyperfine Splitting ◽  
Esr Spectra ◽  
Spin Labels ◽  
Label Study ◽  
Splitting Parameter ◽  
Induced Changes ◽  
Purple Membranes

Abstract Three spin-labelled fatty acids were used to detect the dynamics of lipid bilayer of apomem branes and purple membranes. It was found that ESR spectra of spin labels bound to apo­ membranes showed a temperature-induced changes rather similar to those seen with purple membranes. At the same time, however, the values of hyperfine splitting parameter 2Tm were lower as compared to purple membranes. The results pointed out that the removal of the retinal from purple membranes affects the dynamics of lipid bilayer and apomembranes were more rigid structure than those of purple membranes.

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