| Citation | Stace is the leading UK expert on gas?phase microclusters, key intermediates between the gaseous and condensed states with important implications ranging from atmospheric chemistry through liquid/solid phase transition dynamics to the factors governing quantum size effects in aggregated systems. Among Stace's numerous outstanding contributions are: The first observation of fragmentation in metastable cluster ions; the first identification of quantitative correlations between cluster structure and fragmentation patterns; the first measurement of Coulomb explosion in size?selected multiply charged clusters; the use of cluster ions as models for the preferential solvation of protons in liquid mixtures; the identification of relationships between chemical reactions in clusters and those occurring in organic liquids and also in the upper atmosphere. An elegant recent observation has been the detection of the onset of reactivity as a reagent becomes progressively more surrounded by molecules. Novel experimental techniques have been developed which have enabled high velocity neutral atoms, ejected from cluster ions, to be detected for the first time and the infrared and electronic spectra of molecules and metals solvated in cluster ions to be recorded. Innovative phenomenological models have been developed to explain observations. A key theoretical advance has been the development of accurate simulation procedures using realistic molecular potentials to provide the first quantitatively accurate predictions of phase transition/infrared spectra correlations. This has opened up a new field of experiment which promises to advance significantly our fundamental understanding of phase transition behaviour in microscopic systems. |