Magic numbers in Aln+(H2O)1 cluster cations

Abstract We report the observation of magic numbers in the mass spectrum of Al n + (H 2 O) 1 . These cluster cations were produced in a laser vaporization source in the presence of trace amounts of water. The most prominent magic number species observed was Al 13 + (H 2 O) 1 . We attribute its pronounced intensity to its enhanced stability resulting from the formation of a coordinate bond between the Al 13 + moiety and the oxygen atom of water. The sharing of an oxygen lone electron pair with Al 13 + lends to it some of the character of the 40-valence electron, closed shell Al 13 − magic cluster.