Force constant calculations for tetrakis-trichlorophosphinenickel(0), Ni(PCl 3) 4

Abstract

Force constants for an SVFF approximation are calculated for Ni(PCl 3) 4 using the FG matrix method and vibrational assignments for the A 1, E and F 2 symmetry classes on the basis of T d molecular symmetry. Six primary force constants, involving bond stretching and bond angle deformation, and five interaction force constants are used to fit simultaneously the observe wavenumbers. Comparison is made with the force constants for the free ligand, PCl 3, and for the related species Ni(PF 3) 4. The NiP stretching force constant value for Ni(PCl 3) 4 is 1.67 mdyn Å −1 which is much lower than the corresponding value for NI(PF 3) 4. The PCl stretching force constant in Ni(PCl 3) 4 is also lower than in the free ligand. These changes are discussed in terms of the metal—phosphorus—chlorine bonding in Ni(PCl 3) 4.