The photodissociation of the vinyl radical (C2H3) at 243 nm studied by velocity map imaging

摘要: The technique of velocity map imaging (VELMI) has been applied to study the photodissociation vinyl radical (C2H3) at 243.2 nm in a molecular beam. Using momentum conservation, we show that primary product is singlet vinylidene [H2CC(X 2A′)], or acetylene energies where interconversion between H2CC and HCCH geometries facile. In addition, minor contribution seen which assigned triplet [C2H2(a 3B2)]. We argue out-of-plane motion third H atom necessary bring excited states, A″ symmetry, an A′ symmetry leading products, observed tranlsational energy distribution may evidence barrier this process. heat formation derived be 100.3±4.0 kcal/mol, agreement with literature values. From translational release, derive T0 for C2H2(a 3B2) 28 900 cm−1, does not agree well recent ab initio calculations. Possible reasons disagree...