Knowledge Bank

$XeF(Xv-)$, produced by KrF Laser hotodissociation of $XeF2$, is excited by a doubled dye-laser to $XeF(Bv\prime )$ and $XeF(Cv\prime )$ and the broad-band $B\to A$ and $C\to A$ fluorescence is detected. The B and C states are distinguished by their differing decay rates at low pressure. Through its fluorescence excitation spectrum the $C\leftarrow X$ transition is observed for the first time. The vibrational analysis of the C-X bands locates the $C(v\prime =0)$ level at $775cm-1$ below the $B(v\prime =0)$ level, and yields the first experimental vibrational constants for the C state $(\omega e=346cm-1$ and $\omega exe=2.2cm-1)$. A bandshape analysis of the C-X bands suggests that the equilibrium internuclear separation of the C state lies around 2.45 \AA. Vibrational relaxation and vibrationally resolved collision-induced dissociation of $XeF(Xv-)$ are also observed. Supported by the Defense Advanced Research Projects Agency under contract N0014-80-C-0506,through the office of Naval Research.