Competitive solvation of K+ by C6H6 and H2O in the K+-(C6H6)n-(H2O)m (n = 1–4; m = 1–6) aggregates

The competitive solvation of the potassium ion by benzene and water is investigated at molecular level by means of Molecular Dynamics simulations on the K+-(C6H6)n-(H2O)m (n = 1–4; m = 1–6) ionic aggregates. The preference of K+ to bind C6H6 or H2O is investigated in the range of temperatures in which isomerisation processes are likely by adding water and benzene to the K+-(C6H6)n and K+-(H2O)m aggregates, respectively. Hydrogen bonds and the π-hydrogen bond, in spite of their weakness with respect to the K+-π and K+-H2O interactions, play an important role in stabilising different isomers, thus favouring isomerisation processes. Accordingly with experimental information it has been found that K+ bind preferably C6H6 rather than H2O and that the fragmentation of C6H6 is only observed for aggregates containing four molecules of benzene.