ON THE STRUCTURE OF WATER-ALCOHOL AND AMMONIA ALCOHOL PROTONATED CLUSTERS

Collision-induced dissociation (CID) of protonated ammonia-alcohol and water-alcohol heteroclusters was studied using a triple quadrupole ma ss spectrometer with a corona discharge atmospheric pressure ionizatio n source. CID results suggested that the ammonia-alcohol clusters had NH4+ at the core of the cluster and that hydrogen-bonded alcohol molec ules solvated this central ion. In contrast, CID results in water-alco hol clusters showed that water loss was strongly favored over alcohol loss and that there was a preference for the charge to reside on an al cohol molecule. The results also indicated that a loose chain of hydro gen-bonded molecules was formed in the water-alcohol clusters and that there appeared to be no rigid protonation site or a fixed central ion .