Overtone spectroscopy of molecular complexes containing small polyatomic molecules

The literature on the high-resolution spectroscopic investigation of molecular complexes containing small polyatomic species excited in their vibrational overtones is reviewed. They turn out to be complexes containing acetylene, ammonia and water, mainly excited in their 2CH, 2NH and 2OH vibrations, respectively. The majority of results published on these systems was obtained using an instrumental set-up based on cw-cavity ring-down spectroscopy, built in the 'Laboratoire de Chimie quantique et Photophysique' at the 'Universite libre de Bruxelles' (CQP/ULB) and named FANTASIO+, which is described. It allowed retrieving upper state vibrational pre-dissociation lifetimes, which are highlighted together with more results. The sequence of experiments at CQP/ULB prior and along the line of those supporting the investigation of molecular complexes is briefly illustrated.