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 association with a range of solvent clusters. Neutral atoms of holmium are generated in the gas phase using an effusive oven and are crossed with a beam consisting of solvent/argon clusters. Collisions between the holmium atoms and the clusters lead to the formation of neutral metal-solvent complexes. Ionisation by electron impact in the source of a high resolution mass spectrometer enables measurements to be undertaken on the intensities and fragmentation 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 acetone and acetonitrile, and intensity measurements suggest the preferred coordination 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 Science B.V.