Cu+ in Liquid Ammonia and in Water:  Intermolecular Potential Function and Monte Carlo Simulation

The solvation structure of Cu+ in water and in liquid ammonia has been investigated using the Metropolis Monte Carlo method. The systems consisting of one Cu+ in 215 solvent molecules have been simulated at a temperature of 240 K for ammonia and 298 K for water, respectively. Cu+−ammonia and Cu+−water pair potentials have been newly developed based on ab initio calculations of double-ζ quality. Structural properties were investigated by means of radial distribution functions and their running integration numbers, leading for the first solvation shell to an average coordination number 6 and Cu−N distance of 2.20 Å in ammonia, and to number 6 and Cu−O distance of 2.20 Å in water. The RDFs, coordination number distributions, and pair interaction energy distribution analyses indicate that ligand exchange reactions take place more easily in water than in liquid ammonia.