Time-resolved photoionisation of radicals, clusters and biomolecules: relevant model systems

Laser spectroscopy of isolated molecules is more and more driven by chemically relevant questions rather than toward technological development. In this paper, experiments on selected examples of chemically interesting systems will be reviewed, demonstrating the power of laser spectroscopy in molecular beams. We will discuss experiments on allyl (C3H5) and propargyl (C3H3) radicals as examples of the investigation of unimolecular reactions of hydrocarbon radicals, excited-state proton transfer in 1-naphthol/ammonia clusters as an example of acid-base reactions in hydrogen-bonded clusters, and the photophysics of adenine as an example of the spectroscopy of biological molecules. Time-resolved photoionisation and photoelectron spectroscopy is shown to be a particularly powerful method for unravelling the chemistry of these systems.