Deuterium isotope effect on hydrogen atom abstraction by methyl radicals in acetonitrile at 77 K. evidence for tunneling

Journal Article · Thu Mar 24 04:00:00 EST 1977 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100521a005· OSTI ID:7292990

Sprague, E D

By ESR techniques, the rate of disappearance of methyl radicals at 77/sup 0/K in a crystalline matrix composed largely of acetonitrile-d/sub 3/ was determined. Although hydrogen atom abstraction proceeds readily under such conditions, deuterium atom abstraction was not observed. The methyl radical population decayed extremely slowly at 77/sup 0/K by some alternative mechanism. It was nevertheless established from these measurements that the deuterium isotope effect on abstraction is at least 28,000. Since this is almost 20 times greater than the maximum effect in the absence of tunneling, it is strongly indicated that tunneling is important in hydrogen atom abstraction at 77/sup 0/K.

• Research Organization: Univ. of Cincinnati
• OSTI ID: 7292990
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 81:6; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400302* -- Organic Chemistry-- Isotope Effects-- (-1987)
ALKYL RADICALS
DEUTERIUM
HYDROGEN ISOTOPES
ISOTOPE EFFECTS
ISOTOPES
LIGHT NUCLEI
LOW TEMPERATURE
METHYL RADICALS
NITRIDES
NITROGEN COMPOUNDS
NUCLEI
ODD-ODD NUCLEI
PNICTIDES
RADICALS
STABLE ISOTOPES