15min:

AARON MANN, XIANGLING CHEN, VLADIMIR A. LOZOVSKY, C. BRADLEY MOORE, The Ohio State University, Dept. of Chemistry, 120 W. 18th Avenue, Columbus, Ohio 43210, USA.

Excitation of vinyl radical to the A state leads to the dissociation of vinyl radical via internal conversion into highly excited vibrational levels of the X state. This was used as a method of energy deposition above the dissociation barrier of the X state. Velocity maps of H and D atoms that are products of CH₂=CH and CD₂=CH dissociation accompanied by acetylene, were measured in the excitation energy range E ~ 6750 - 9150 cm^-1 above the dissociation barrier of the X state. Rovibrational energy dependencies on the excitation energy, E, inferred for acetylene and d₁-acetylene products are compared with theoretically predicted ones. An upper limit of 1.3 10¹¹ s^-1 is derived for the rate constant of H-atom scrambling between the and carbon atoms.