Rovibrational spectroscopy of the C2H2Ar van der Waals complex, using a fluorescence depletion infrared-ultraviolet double resonance technique

A rovibrational spectrum of the acetylene-argon van der Waals (vdW) complex, C2H2Ar, has been measured in the 1.525 μm ‘2νCH’ overtone region by a time-resolved infrared-ultraviolet double resonance method. Infrared absorption by the vdW complex is recorded as a depletion of laser-induced rovibronic fluorescence intensity, providing a novel way to measure rovibrational spectra of simple vdW complexes and to study their predissociation dynamics.