Observation of the C(3/2)←X(1/2) transition in XeF

XeF(Xv′′), produced by KrF laser photodissociation of XeF2, is excited by a doubled dye laser to XeF(Bv′) and XeF(Cv′), and the broadband B→A and C→A fluorescence is detected. The B and C states are distinguished by their differing decay times at low pressure. The C←X transition is observed for the first time through its fluorescence excitation spectrum. The vibrational analysis of the C–X bands locates the C(v′=0) level at 775 cm−1 below the B(v′=0) level, and yields the first experimental vibrational constants for the C state. A band shape analysis of the C–X bands suggests that the equilibrium internuclear separation of the C state lies around 2.45 Å. Vibrational relaxation and vibrationally resolved collision-induced dissociation of XeF(Xv′′) is also observed.