Gas phase acidity of water clusters.

In the present work, we have estimated the gas-phase acidity of different water clusters, i.e. , (H 2 O) n , n = 1-20, 30, 35, 42, 54, 80, and 100. The present work indicates that the gas-phase acidity of the terminal hydrogen atom increases with the size of water clusters and starts converging at (H 2 O) 30 . Furthermore, the present work also indicates that the gas-phase acidity of a terminal hydrogen atom is higher than that of the corresponding bulk hydrogen atom for the same size of water cluster.