Rate and Mechanisms for Water Exchange around Li⁺(aq) from MD Simulations

The solvent exchange rate of aqueous Li+ has been determined by employing the reactive flux method in combination with very long molecular dynamics simulations based on effective three-body ion−water potentials. The mechanisms for the resulting exchange events have been studied in considerable detail and analyzed in terms of the five commonly discussed exchange classes: associative (A), dissociative (D), and interchange (I, Ia, Id). Furthermore, the stereochemistry (cis, trans) of each exchange has been monitored and correlated with the exchange classes. Most of the exchanges are associative or associative interchanges and of a trans type, although the trans exchanges are less probable on a purely statistical basis.