Determination of the relative signs of the hyperfine coupling constants for the phosphonenitroxyl radical from the ESR spectra in weak fields

1981 ◽  
Vol 16 (3) ◽  
pp. 305-307
Author(s):  
B. M. Odintsov ◽  
A. A. Barlev ◽  
A. V. Il'yasov
Keyword(s):  
Hyperfine Coupling ◽  
Esr Spectra ◽  
Coupling Constants ◽  
Hyperfine Coupling Constants ◽  
Weak Fields

Substituent effects on benzylic radical hydrogen hyperfine coupling constants. Part 4. The effect of branching of the alkyl substituent

1985 ◽  
Vol 63 (9) ◽  
pp. 2378-2383 ◽  
Author(s):  
Danial D. M. Wayner ◽  
Donald R. Arnold
Keyword(s):  
Hyperfine Coupling ◽  
Substituent Effects ◽  
Alkyl Substituent ◽  
Esr Spectra ◽  
Coupling Constants ◽  
Molecular Orbital Calculations ◽  
Methyl Ethyl ◽  
Hyperfine Coupling Constants ◽  
Benzyl Radical ◽  
Spin Resonance

The effects of substituents in the meta and para positions of the benzyl radical on the α-hydrogen hyperfine coupling constants (hfc's) are discussed. The electron spin resonance (esr) spectra of the para-methyl, ethyl, isopropyl, and tert-butyl substituted benzyl and cumyl radicals are analysed. Hyperconjugation involving the C—C bond is 40–60% as effective as C—H hyperconjugation for delocalizing spin density. This conclusion is supported by INDO molecular orbital calculations. Similar analysis of the 13Cmr spectra of the para-alkyl substituted cumyl carbocations provides evidence that C—C hyperconjugation is 75–90% as effective as C—H hyperconjugation for delocalizing charge density.

Determination of Hyperfine Coupling Constants of Fluorinated Diphenylacetylene Radical Anions by Magnetic Field-Affected Reaction Yield Spectroscopy

2018 ◽  
Vol 123 (2) ◽  
pp. 505-516
Author(s):  
Victoria A. Sannikova ◽  
Maria P. Davydova ◽  
Peter S. Sherin ◽  
Simon V. Babenko ◽  
Valeri V. Korolev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hyperfine Coupling ◽  
Coupling Constants ◽  
Reaction Yield ◽  
Radical Anions ◽  
Hyperfine Coupling Constants
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