Laser IR fragmentation of molecular clusters: the role of channels for energy input and relaxation, influence of surroundings, dynamics of fragmentation
Institute of Spectroscopy, Russian Academy of Sciences, ul. Fizicheskaya 5, Troitsk, Moscow, 108840, Russian Federation
The results of research into the infrared (IR) laser fragmentation of molecular clusters by resonant vibrational excitation of cluster molecules are presented with special attention given to the role of environment, the energy input and relaxation channels and dynamical aspects. For this purpose, the results of experiments with free homogeneous and heterogeneous molecular clusters and of experiments with clusters inside or on the surface of large inert gas clusters are analyzed, the laser excitation pulses varying in wavelength and duration. The data on the character and rate of cluster fragmentation and on the intramolecular and intracluster vibrational energy relaxation times in clusters are discussed. Results on the formation, structure and dynamics of molecular clusters and atom-molecular complexes obtained by IR-photodissociation spectroscopy and the spectroscopy of photo fragments are analyzed. Methods for generating heterogeneous molecular clusters, for size-selecting clusters and methods for studying the IR dissociation and IR fragmentation of clusters are also briefly considered.