Cluster ion studies of Ho2+ and Ho3+ solvation in the gas phase

An attempt has been made to prepare triply charged ions of holmium in assoc iation with a range of solvent clusters. Neutral atoms of holmium are gener ated in the gas phase using an effusive oven and are crossed with a beam co nsisting of solvent/argon clusters. Collisions between the holmium atoms an d the clusters lead to the formation of neutral metal-solvent complexes. Io nisation by electron impact in the source of a high resolution mass spectro meter enables measurements to be undertaken on the intensities and fragment ation patterns of the resultant ions as a function of size. Only singly and doubly charged complexes are observed when water and methanol are used as solvents. Stable triply charged complexes are formed with the solvents acet one and acetonitrile, and intensity measurements suggest the preferred coor dination number in both cases is 6. Measurements following the collisional activation of the holmium/acetonitrile complexes show evidence of chemical reactivity. (Int J Mass Spectrom 188 (1999) 113-119) (C) 1999 Elsevier Scie nce B.V.