Evidence of triplet ethylene produced from photodissociation of ethylene sulfide

Tunable synchrotron radiation has been used to probe the dissociation dynam ics of ethylene sulfide, providing selective determination of the translati onal energy distributions of both excited (D-1) and ground-state (P-3) sulf ur atoms, with momentum-matching to the ethylene cofragments. The results s uggest the presence of a channel giving S(P-3) in conjunction with triplet ethylene C2H4 (B-3(1u)), and allow for the first experimental measure of th e energy of the latter species near the equilibrium geometry, in which the two methylene groups occupy perpendicular planes. (C) 2000 American Institu te of Physics. [S0021-9606(00)02524-1].