Showing papers by "Ffrancon Williams published in 1983"
TL;DR: In this article, the ring-opened 2-oxa-trimethylene radical was shown to have a symmetric (C2ν) planar structure similar to that of the isoelectronic allyl radical.
29 citations
TL;DR: In this article, an intense isotropic ESR spectrum of CF3CCl2 is generated by annealing γ-irradiated samples of CF2CCl3 above 145 K, the sudden spectral change being irreversible and probably corresponding to the loss of a chloride ion from the CF3Cl3− radical anion.
Abstract: An intense isotropic ESR spectrum of CF3CCl2 is generated by annealing γ‐irradiated samples of CF2CCl3 above 145 K, the sudden spectral change being irreversible and probably corresponding to the loss of a chloride ion from the CF3CCl3− radical anion. Satellite lines detected at high gain are assigned to CF313CCl2 with a 13C hyperfine coupling of 67.3 G, showing that th radical possesses a more planar configuration than that of the CCl3 radical (13C hfc≂116 G). This result strongly supports a previous argument that increasing the electronegativity of the α substituent is much less important than the effect of π‐conjugative destabilization in promoting the pyramidality of alkyl radicals. (AIP)
6 citations
TL;DR: In this paper, large non-aldehydic 1H hyperfine couplings in the radical cations of four carbonyl compounds are assigned to long-range hyperfine interactions relayed through a trans(W-plan) arrangement of C-C and C-H σ bonds.
Abstract: Large non-aldehydic 1H hyperfine couplings in the radical cations of four carbonyl compounds are assigned to long-range hyperfine interactions relayed through a trans(W-plan) arrangement of C–C and C–H σ bonds; for example, the two strongly coupled hydrogens in the cyclohexanone radical cation are identified by deuterium substitution as the ‘δ’ equatorial pair at C-3 and C-5 rather than the ‘γ’ equatorial pair at C-2 and C-6 assigned previously.
3 citations