Isotope effect in reactions of CH3 and CD3 radicals in glassy solutions of CH3OH and C2H5OH in methanol-d3 at 77 K

Abstract

The decay kinetics of methyl radical isotopomers has been studied at 77 K in glassy mixtures xR′HOH+(1−x)CD3OH, where R′HOH is either CH3OH or C2H5OH. In matrices with a small fraction of H component (x⩽0.02) the CD3 radicals decay twice as quickly as the CH3 radicals. As the H content in the mixture increases, the difference in the decay rates of the methyl radical isotopomers first gradually decreases to zero, and for x>0.2 CH3 decays faster than CD3 . A comparison is made with previous results for ethanol glass.