Ag(I) ion in liquid ammonia

Abstract

Structural and dynamical properties of Ag + in liquid ammonia have been evaluated on the basis of a molecular dynamics (MD) simulation by the ab initio quantum mechanical/molecular mechanical (QM/MM) method. The most important region, the first solvation shell, was treated by ab initio quantum mechanics at RHF (Restricted Hartree–Fock) level using double- ζ plus polarization basis sets for Ag + and ammonia, respectively. For the remaining region in the system newly constructed three-body corrected potential functions were used. The first solvation shell shows a tetrahedral structure with an Ag–N distance of 2.54 Å, with no ammonia exchange process observable within a simulation time of 16 ps. The mean residence time (MRT) of ammonia molecules in the second solvation shell was determined as 12.7 ps. A force constant of 26 N m −1 was observed for the ion–ligand stretching frequency, indicating a more the stable solvate complex than for Ag + in water.