The dynamics of the Cl+C2H6→HCl(v′,j′)+C2H5 reaction at 0.24 eV:: Is ethyl a spectator?

The hydrogen atom abstraction reaction between Cl(P-2(3/2)) and ethane has been studied at a mean collision energy of 0.24 eV. The experiments were performed in a coexpansion of molecular chlorine and ethane, with the atomic Cl reactants generated by laser photodissociation of Cl-2 at 355 nm. HCl(v('),j(')) products were detected quantum state selectively using (2+1) resonantly enhanced multiphoton ionization, coupled with velocity-map ion imaging. The ion images were used to determine center-of-mass angular and kinetic energy release distributions. Several analysis methods were employed and have been carefully assessed. It is shown that the single beam experiments can be used with confidence to determine both center-of-mass angular and energy release distributions. For the title reaction the angular distribution is found to be forward peaking, with on average 22% of the available energy channeled into internal excitation of the ethyl coproducts. Possible sources of this internal excitation are discussed. (C) 2003 American Institute of Physics.