Proton hyperfine tensors in nitroxide radicals

Journal Article · Thu Aug 23 04:00:00 EDT 1990 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100380a013· OSTI ID:6383078

Brustolon, M; Maniero, A L; Segre, U ^[1]; Ottaviani, M F ^[2]; Romanelli, M ^[3]

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1. Universita di Padova (Italy)
2. Universita di Firenze (Italy)
3. Universita della Basilicata (Italy)

The proton hyperfine tensors of five nitroxide radicals have been obtained by ENDOR spectroscopy in frozen solution. The spectra are interpreted by computing the dipolar hyperfine interaction and simulating the spectra. EPR spectra in solution of the same radicals have been simulated by taking into account the effects of the proton hyperfine tensors. We have been able to reproduce accurately the line broadening effects of the proton hyperfine structures inside each nitrogen hyperfine component and we have determined the correlation times for the rotational motion. In the case of the radical Tempol, our analysis allows discrimination between the effects due to the protons of the axial and equatorial methyl groups. On the basis of experimental evidence we can attribute the larger isotropic hyperfine coupling constant to the axial methyl protons. The possible use of the present results for interpreting the spectra of other nitroxide radicals is discussed.

• OSTI ID: 6383078
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 94:17; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
BARYONS
CALCULATION METHODS
ELEMENTARY PARTICLES
ENDOR
FERMIONS
HADRONS
HYPERFINE STRUCTURE
MAGNETIC RESONANCE
NITROXYL RADICALS
NUCLEONS
PROTONS
RADICALS
RESONANCE
SPECTROSCOPY
TENSORS