The opto-thermal detection method has been used to obtain the first gas-phase infrared spectrum of the non-linear HCN-(HF)2 complex. Rotational constants in the ground and vibrationally excited states have been determined, as well as the band origin and vibrational predissociation lifetime. The experimental spectrum is a direct result of the excitation of the C-H stretching vibration in the complex. Two other featureless vibrational bands have been observed which are tentatively assigned to the HF stretches in this complex.
