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

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

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

K. U. Ingold
, D. C. Nonhebel
, J. C. Walton^*

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

Abstract

The electron paramagnetic resonance (EPR) spectra of CH₃CH₂C(CH₃)₂CH₂· and CH₃CH₂C(CD₃)₂CH₂· indicate that at 95 K these radicals exist in a rigid conformation with respect to rotation about the three C_β-C_γ bonds and that the δ-methyl group (of the ethyl moiety) is gauche to one methyl and to the CH₂· group. Analysis of the γ-H hyperfine splittings indicates that in the preferred conformation about the C_α-C_β bond the SOMO eclipses one of the γ-methyl groups, not the γ-ethyl group. The internal rotation barriers of the CD₃ and ethyl groups were estimated to be ca. 4 and 6 kcal/mol from the exchange broadening in the EPR spectra at higher temperatures.

Original language	English
Pages (from-to)	4424-4426
Number of pages	3
Journal	Journal of Physical Chemistry
Volume	89
Issue number	21
Publication status	Published - 1 Dec 1985

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@article{06e496ab78cd4d4e87ed2de7d7885c15,

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

abstract = "The electron paramagnetic resonance (EPR) spectra of CH3CH2C(CH3)2CH2· and CH3CH2C(CD3)2CH2· indicate that at 95 K these radicals exist in a rigid conformation with respect to rotation about the three Cβ-Cγ bonds and that the δ-methyl group (of the ethyl moiety) is gauche to one methyl and to the CH2· group. Analysis of the γ-H hyperfine splittings indicates that in the preferred conformation about the Cα-Cβ bond the SOMO eclipses one of the γ-methyl groups, not the γ-ethyl group. The internal rotation barriers of the CD3 and ethyl groups were estimated to be ca. 4 and 6 kcal/mol from the exchange broadening in the EPR spectra at higher temperatures.",

author = "Ingold, \{K. U.\} and Nonhebel, \{D. C.\} and Walton, \{J. C.\}",

year = "1985",

month = dec,

day = "1",

language = "English",

volume = "89",

pages = "4424--4426",

journal = "Journal of Physical Chemistry",

issn = "0022-3654",

publisher = "American Chemical Society (ACS)",

number = "21",

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TY - JOUR

T1 - Conformational analysis of the 2,2-dimethylbutyl radical by EPR spectroscopy

AU - Ingold, K. U.

AU - Nonhebel, D. C.

AU - Walton, J. C.

PY - 1985/12/1

Y1 - 1985/12/1

N2 - The electron paramagnetic resonance (EPR) spectra of CH3CH2C(CH3)2CH2· and CH3CH2C(CD3)2CH2· indicate that at 95 K these radicals exist in a rigid conformation with respect to rotation about the three Cβ-Cγ bonds and that the δ-methyl group (of the ethyl moiety) is gauche to one methyl and to the CH2· group. Analysis of the γ-H hyperfine splittings indicates that in the preferred conformation about the Cα-Cβ bond the SOMO eclipses one of the γ-methyl groups, not the γ-ethyl group. The internal rotation barriers of the CD3 and ethyl groups were estimated to be ca. 4 and 6 kcal/mol from the exchange broadening in the EPR spectra at higher temperatures.

AB - The electron paramagnetic resonance (EPR) spectra of CH3CH2C(CH3)2CH2· and CH3CH2C(CD3)2CH2· indicate that at 95 K these radicals exist in a rigid conformation with respect to rotation about the three Cβ-Cγ bonds and that the δ-methyl group (of the ethyl moiety) is gauche to one methyl and to the CH2· group. Analysis of the γ-H hyperfine splittings indicates that in the preferred conformation about the Cα-Cβ bond the SOMO eclipses one of the γ-methyl groups, not the γ-ethyl group. The internal rotation barriers of the CD3 and ethyl groups were estimated to be ca. 4 and 6 kcal/mol from the exchange broadening in the EPR spectra at higher temperatures.

UR - https://www.scopus.com/pages/publications/33845378221

M3 - Article

AN - SCOPUS:33845378221

SN - 0022-3654

VL - 89

SP - 4424

EP - 4426

JO - Journal of Physical Chemistry

JF - Journal of Physical Chemistry

IS - 21

ER -

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

Abstract

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