Small Cluster Chemistry

Our activities encompass studies of a broad variety of physicochemical properties of cluster systems. The immense interest in clusters is fueled by the recognition of the central role they play in many modern technologies and in natural phenomena. The potential of clusters as a means of optimization of existing technologies, developing principally new technological processes, materials, and devices, and in managing natural phenomena, especially those of environmental concern, is truly unparalleled. To make this potential a reality a comprehensive understanding of the properties of clusters as a function of their material(s), size, structure, temperature, etc. is needed.

The emphasis in our program is on fundamental studies leading to such an understanding. Its particular strength is that it combines both experimental and theoretical components, which synergistically enhance each other. Our research focuses on metal clusters because of their particular technological relevance. The elements studied vary from alkali, through transition, to coinage metals and their combinations. The properties investigated include geometrical structures, stability, phases and phase changes, fragmentation mechanisms, electronic features (e.g., ionization potentials, electron affinities), chemical reactivity with a broad variety of molecules, optical and magnetic properties, etc. The cluster features change, in general, with size, and the different properties may be correlated. The central goals include uncovering and understanding the size-dependence of and the correlations between the different features. For example, the chemical reactivity of a cluster of a given metal with a chosen reactant molecule may strongly depend on the cluster size, structure, and temperature. Unraveling the mechanisms through which these latter affect the reaction pathways and rates is crucial for improving, or even fully optimizing, the efficiency and selectivity of real catalysts.