CLUSTERS - STRUCTURE, ENERGETICS, AND DYNAMICS OF INTERMEDIATE STATESOF MATTER

The field of cluster research can trace its origins back to the mid-ni neteenth century when early studies of colloids, aerosols, and nucleat ion phenomena were reported. The field underwent a resurgence of inter est several decades ago when well-defined clusters were observed in su personic expansions that could be investigated using mass spectrometer s. The advent of the laser provided a new dimension, enabling detailed spectroscopic observations through the probing of systems of varying size and degree of solvation. Modern interest derives from recognition that interrogating clusters provides a way of studying the energetics and dynamics of intermediate states of matter as cluster systems evol ve from the gas toward the condensed state. Herein, we endeavor to hig hlight some of the significant advances which have been made during th e past several decades that have led to a nearly explosive growth of i nterest in the field of cluster science. Finally, we conclude that the field will continue to expand through interests in basic phenomena, a s well as through numerous applications of cluster research to fields ranging from catalysis to the quest for new cluster-assembled material s.