Electron spin resonance studies on radiolysis of crystalline methanol at 4. 2 K

Journal Article · Wed May 09 04:00:00 EDT 1979 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00504a002· OSTI ID:5938388

Toriyama, K; Iwasaki, M

Radiolysis of crystalline methanol and the structure of radicals produced have been studied at 4.2 K using electron spin resonance spectroscopy. It has been observed for the first time that CH/sub 3/O and CH/sub 3/ are formed as major products together with conventional CH/sub 2/OH in pure CH/sub 3/OH irradiated at 4.2 K. The direct evidence was obtained that both CH/sub 3/O and CH/sub 3/ convert into CH/sub 2/OH below 77 K. Intramolecular hydrogen atom transfer is suggested for the conversion from CH/sub 3/O into CH/sub 2/OH. Besides these isolated radicals, considerable amounts of radical pairs between CH/sub 3/ and CH/sub 2/OH were formed. CH/sub 3/ in this pair also converts into CH/sub 2/OH forming radical pairs between CH/sub 2/OH below 77 K. The change in the radical pair separation indicates that CH/sub 3/ abstracts a hydrogen atom from the neighboring CH/sub 3/ group forming CH/sub 2/OH. It is suggested that the radical pairs are formed from recombination of an electron and a cationic species. (The electronic and geometrical structure of CH/sub 3/O has also been discussed.) The radical is the oxygen-centered ..pi.. radical and the CH/sub 3/ group undergoes tunneling rotation at 4.2 K. From the A- and E-line splittings, B/sub 0/ and B/sub 2/ in the cos/sup 2/ theta rule for the ..beta.. proton coupling in the oxygen-centered ..pi.. radicals have been estimated to be 5 and 94 G, respectively. 9 figures, 3 tables.

• Research Organization: Government Industrial Research Inst., Nagoya, Japan
• OSTI ID: 5938388
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 101:10; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400600* -- Radiation Chemistry
ALCOHOLS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHEMISTRY
CRYSTALS
DATA
DATA FORMS
DECOMPOSITION
ELECTRON SPIN RESONANCE
EXPERIMENTAL DATA
HYDROXY COMPOUNDS
INFORMATION
IRRADIATION
ISOLATED VALUES
KINETICS
LOW TEMPERATURE
MAGNETIC RESONANCE
METHANOL
NUMERICAL DATA
ORGANIC COMPOUNDS
PULSED IRRADIATION
RADIATION CHEMISTRY
RADIATION EFFECTS
RADICALS
RADIOLYSIS
REACTION KINETICS
RESONANCE
TEMPERATURE DEPENDENCE
TUNNELING
ULTRALOW TEMPERATURE
YIELDS