Infrared Spectroscopy of Radical Cation Clusters (NH) and (NH).

The ionization of protic molecules such as HO and NH in the condensed phase initiates ion-molecule reactions, which remain poorly understood. Studies of the structure and reactivity of small ionic clusters in molecular beams have yielded a wealth of information on protonated clusters. However, unprotonated radical cation clusters have a low concentration in a typical experiment and thus remain challenging.