Temperature-dependent hyperfine coupling constants in electron spin resonance
- 1 April 1974
- journal article
- research article
- Published by Taylor & Francis in Molecular Physics
- Vol. 27 (4) , 949-957
- https://doi.org/10.1080/00268977400100871
Abstract
The temperature dependence of the hydroxyl proton splittings in the radical cation of 1,2,4,5-tetrahydroxybenzene has been measured over the temperature range -80°C to +60°C. The ring proton splittings show no significant dependence upon temperature. The hyperconjugative contribution to the hydroxyl proton coupling has been calculated as a function of temperature for a range of values of V 0, the two-fold barrier to rotation of an individual hydroxyl group, using numerical solutions to the Mathieu equation. This, together with the results of McLachlan SCF-MO calculations for this system, leads to a value of V 0 of 24 ± 2 kJ mol-1 and to an estimate of the spin-polarization parameter Q OHH of -3·87 ± 0·05 mT.Keywords
This publication has 15 references indexed in Scilit:
- Electron spin resonance studies of conformations and hindered internal rotation in transient free radicalsThe Journal of Physical Chemistry, 1971
- Temperature variation of the proton hyperfine splittings in the E.S.R. spectrum of the biacetyl semidione radicalMolecular Physics, 1971
- Temperature dependence of the proton hyperfine splittings in the E.S.R. spectrum of the biacetyl semidione radicalMolecular Physics, 1971
- Temperature-dependent methoxyl and hydroxyl splitting constants in the electron spin resonance spectra of cation radicalsThe Journal of Physical Chemistry, 1969
- Electron spin resonance studies of hydroxysemiquinone radicals. Hydrogen-deuterium isotope effects in intramolecular hydrogen bondsJournal of the American Chemical Society, 1969
- The vibrational spectrum and torsion of phenolJournal of Molecular Spectroscopy, 1967
- Solvation spectra. Part 10.—Electron spin resonance spectrum of monoprotonated durosemiquinoneTransactions of the Faraday Society, 1966
- An electron resonance study of rotational isomerism in the naphthazarin semiquinone cationMolecular Physics, 1963
- Self-consistent field theory of the electron spin distribution in π-electron radicalsMolecular Physics, 1960
- Molecular Orbital Calculations of Vibrational Force Constants. I. EthyleneThe Journal of Chemical Physics, 1948