CARBON-13 HYPERFINE SPLITTING IN THE ELECTRON SPIN RESONANCE SPECTRA OF SEMIQUINONES AND CYCLOOCTATETRAENE
Abstract
Measurements were performed on the C-13 hyperfine splitting in the electron spin resonance spectra of a series of methyl- and chloro-substituted semiquinones and of the cyclooctatetraene anion radical. The splittings were observed from C-13 nuclei present in natural abundance (about 1%); the C-13 satellites were distinguished from spurious low-intensity lines arising from sidereaction produced radical impurities by means of careful intensity measurements as well as other techniques. The largest observed C-13 splitting had a magnitude of 1.7 gauss. In the p-benzosemiquinone ion, a previously observed line of low intensity was identified as a splitting arising from C-13 nuclei, and was assigned, on the basis of intensity measurements, to the 4 CH carbon atoms. Splitting constants tentatively identified with the methyl C atoms of the methyl-substituted compounds were in the neighborhood of 1.5 gauss. The splitting in the cyclooctatetraene anion indicates that the 3 sigma bonds attached to a C atom lie in a single plane. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 15, 1961
- Accession Number
- AD0255803
Entities
People
- George K. Fraenkel
- Herbert L. Strauss
Organizations
- Columbia University