Gas-phase basicities and proton affinities of alkali metal oxides and hydroxides. A theoretical study

Coupled cluster and DFT B3LYP calculations have been used to determine the structures, heats of formation, and gas-phase basicities of alkaline metal oxides M2O and hydroxides MOH, where M = Li, Na and K. Structures calculate d at CCSD(T,Full)/ 6-31 + + G(2df,2pd), B3LYP/6-311 + G**, and B3LYP/6-311 + G(3df,3pd) levels of theory were in a good agreement with each other and available experimental estimates. Atomic charges and the Bader's topologica l charge density analysis indicate that the bonding between M and O is ioni c in all studied species. Calculated heats of formation were used to discri minate between different experimental values. Proton affinities of 1193, 13 19 and 1374 kJ/mol are suggested for Li2O, Na2O, and K2O, respectively. (C) 2001 Elsevier Science B.V. All rights reserved.