Laser desorption jet cooling spectroscopy of organic clusters

Abstract

While laser ablation is often used to create clusters, laser desorption at lower fluences can be used to probe clusters already present on a surface or van der Waals clusters formed between desorbed species and gas phase atoms. As an example of the former we discuss a study of para amino benzoic acid dimers. The dimers are formed by laser desorbing the monomer into a supersonic expansion. With the technique of laser desorption jet cooling it is also possible to form van der Waals clusters and species in the drive gas. As an example we discuss the spectroscopy of triphenylamine/argon clusters. Finally, the same technique allows the study of species on the surface, rather than clusters formed by the volatilization itself. A dramatic example is the formation of carbon clusters by laser ablation in a separate step and their subsequent study by laser desorption.