Knowledge Bank

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 $E\approx 6750-9150cm-1$ 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 $1.3.1011s-1$ is derived for the rate constant of H-atom scrambling between the $\alpha$ and $\beta$ carbon atoms.