Production of doubly charged clusters (H2O)n center dot Ba2+ and (H2O)n center dot Ca2+ under low temperature fast atom bombardment conditions

Production of doubly charged ions of alkaline earth metals Ba2+ and Ca2+ an d their doubly charged clusters with water molecules (H2O)(n). Ba2+, (H2O)( n). Ca2+(n = 1, 2, 3) by means of low temperature fast atom bombardment tec hnique is observed in the case of crystalline hydrates of BaCl2 and CaCl2, salts, formed during freezing of water-salt solutions. Reasons for a possib ility of production of the doubly charged species in the case of the two in dicated salts and their absence in the case of chlorides of some other diva lent metals (Mg, Mn, Co, Cu, Zn) are discussed. As to singly charged second ary ions Me+, MeCl+, MeOH+, [(H2O)(n). MeCl](+), [(H2O)(n). MeOH](+) (where Me is metal), high efficiency of their production from crystalline hydrate s was observed and possible explanation of the phenomenon is suggested. (C) 2000 Elsevier Science B.V.