Photoelectron spectroscopy of methyl, ethyl, isopropyl, and tert-butyl radicals. Implications for the thermochemistry and structures of the radicals and their corresponding carbonium ions
Journal Article
·
· J. Am. Chem. Soc.; (United States)
The first photoelectron bands of the series of simple alkyl free radicals CH/sub 3/, CH/sub 3/CH/sub 2/, CH/sub 3/CD/sub 2/, CH/sub 3/CHCH/sub 3/, and C(CH/sub 3/)/sub 3/ have been obtained. The adiabatic and vertical ionization potentials, respectively, are 9.84 +- 0.02 eV for methyl radical, 8.39 +- 0.02 and 8.51 +- 0.02 eV for ethyl radical, 8.38 +- 0.02 and 8.50 +- 0.02 eV for ethyl-l,l-d/sub 2/ radical, 7.36 +- 0.02 and 7.69 +- 0.02 eV for isopropyl radical, and 6.70 +- 0.03 and 6.92 +- 0.03 eV for tert-butyl radical. The heats of formation of the corresponding carbonium ions are calculated to be 261.8 +- 0.5 kcal/mol for methyl cation, 219.2 +- 1.1 kcal/mol for ethyl cation, 187.3 +- 1.1 kcal/mol for isopropyl cation, and 162.9 +- 1.2 kcal/mol for tert-butyl cation. The implications of these data for the gas-phase proton affinity scale are explored. Band structure is resolved, and possible assignments are presented. The results are discussed in terms of the interactions of methyl groups with trigonal carbon radical and ion centers.
- Research Organization:
- California Inst. of Tech., Pasadena
- OSTI ID:
- 5763206
- Journal Information:
- J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 101:15; ISSN JACSA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Photoelectron spectroscopy of 1-propyl, 1-butyl, isobutyl, neopentyl, and 2-butyl radicals: free radical precursors to high-energy carbonium ion isomers. [Studied at elevated temperature to increase extent of radical decomposition]
Detection and investigation of allyl and benzyl radicals by photoelectron spectroscopy
ESR investigation of ester. pi. -cation radicals in a freon matrix at low temperatures: evidence for unusual barriers to methyl group rotation and intramolecular bonding
Journal Article
·
Wed Jul 11 00:00:00 EDT 1984
· J. Am. Chem. Soc.; (United States)
·
OSTI ID:6417014
Detection and investigation of allyl and benzyl radicals by photoelectron spectroscopy
Journal Article
·
Wed May 24 00:00:00 EDT 1978
· J. Am. Chem. Soc.; (United States)
·
OSTI ID:6626957
ESR investigation of ester. pi. -cation radicals in a freon matrix at low temperatures: evidence for unusual barriers to methyl group rotation and intramolecular bonding
Journal Article
·
Wed Apr 25 23:00:00 EST 1984
· J. Phys. Chem.; (United States)
·
OSTI ID:6562543
Related Subjects
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400302 -- Organic Chemistry-- Isotope Effects-- (-1987)
ALKYL RADICALS
BUTYL RADICALS
DATA
DATA FORMS
DEUTERIUM
ELECTRON SPECTROSCOPY
ETHYL RADICALS
EXPERIMENTAL DATA
HYDROGEN ISOTOPES
INFORMATION
IONIZATION POTENTIAL
ISOLATED VALUES
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
METHYL RADICALS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
PROPYL RADICALS
RADICALS
SPECTROSCOPY
STABLE ISOTOPES
THERMODYNAMIC PROPERTIES
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400302 -- Organic Chemistry-- Isotope Effects-- (-1987)
ALKYL RADICALS
BUTYL RADICALS
DATA
DATA FORMS
DEUTERIUM
ELECTRON SPECTROSCOPY
ETHYL RADICALS
EXPERIMENTAL DATA
HYDROGEN ISOTOPES
INFORMATION
IONIZATION POTENTIAL
ISOLATED VALUES
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
METHYL RADICALS
NUCLEI
NUMERICAL DATA
ODD-ODD NUCLEI
PHOTOELECTRON SPECTROSCOPY
PHYSICAL PROPERTIES
PROPYL RADICALS
RADICALS
SPECTROSCOPY
STABLE ISOTOPES
THERMODYNAMIC PROPERTIES