AB-INITIO STUDY OF PHOSPHORUS ION COMPLEXES OF AMMONIA AND WATER

A theoretical ab-initio study of P(OH2)n+, P(NH3)n+, and P(NH3)(OH2)+ (n = 1, 2) has been carried out. Optimum geometries, binding energies, and Mulliken charges have been determined. It was found that the one-ligand complexes present larger binding energies than those expected from an electrostatic binding mechanism. This effect is attributed to some electron dative bonding character. The two ligand complexes have binding energy values closer to the electrostatic ones, indicating that the bond has a higher electrostatic character than that of the one-ligand complexes. The dependency of the binding energies and geometries with respect to the electron correlation and basis sets is discussed.