Shs. Wilson et al., A REINVESTIGATION OF THE NEAR-ULTRAVIOLET PHOTODISSOCIATION DYNAMICS OF THE METHYL RADICAL, Chemical physics letters, 227(4-5), 1994, pp. 456-460
The translational energy spectrum of H Rydberg atoms resulting from th
e photolysis of the methyl radical (CH3) at 216.3 nm has been recorded
. The use of pulsed supersonic jet flash pyrolysis of azomethane (CH3N
2CH3) as a clean source of methyl radicals has allowed a clear analysi
s of the data, eliminating possible interference from other molecular
species. The measured times-of-flight of the resulting H atoms indicat
e that the partner CH2 fragments resulting from predissociation of CH3
(B) radicals are formed in their low-lying a excited state, as predic
ted by theory. An earlier contradictory report of this dissociation pr
ocess, using methanethiol (CH3SH) as a photolytic precursor to generat
e methyl radicals, has been reinterpreted in terms of secondary dissoc
iation of ground-state thiomethoxy radicals (CH3S) yielding electronic
ally excited thioformaldehyde CH2S(A1A2) + H(2S).