Conformational analysis of the 2,2-dimethylbutyl radical by EPR spectroscopy

Journal Article · Thu Oct 10 04:00:00 EDT 1985 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100267a006· OSTI ID:6436812

Ingold, K U; Nonhebel, D C; Walton, J C

The electron paramagnetic resonance (EPR) spectra of CH/sub 3/CH/sub 2/C(CH/sub 3/)/sub 2/CH/sub 2/ and CH/sub 3/CH/sub 2/C(CD/sub 3/)/sub 2/CH/sub 2/ indicate that at 95 K these radicals exist in a rigid conformation with respect to rotation about the three C/sub ..beta../-C/sub ..gamma../ bonds and that the delta-methyl group (of the ethyl moiety) is guache to one methyl and to the CH/sub 2/ group. Analysis of the ..gamma..-H hyperfine splittings indicates that in the preferred conformation about the C/sub ..alpha../-C/sub ..beta../ bond the SOMO eclipses one of the ..gamma..-methyl groups, not the ..gamma..-ethyl group. The internal rotation barriers of the CD/sub 3/ and ethyl groups were estimated to be ca. 4 and 6 kcal/mol from the exchange broadening in the EPR spectra at higher temperatures. 15 references, 1 figure.

• Research Organization: National Research Council of Canada, Ottawa, Ontario
• OSTI ID: 6436812
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 89:21; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ALKYL RADICALS
BUTYL RADICALS
CONFORMATIONAL CHANGES
DATA
DEUTERIUM
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
HYDROGEN ISOTOPES
HYPERFINE STRUCTURE
INFORMATION
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
LOW TEMPERATURE
MAGNETIC RESONANCE
METHYL RADICALS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
RADICALS
RESONANCE
STABLE ISOTOPES