PF3, PF2, and PF on Ni(111): Theoretical Aspects of Their Chemisorption.

摘要

The chemisorption of (Phosphorus trifluoride), (Phosphorus difluoride) and (Phosphorus fluoride on (Nickel)(111) is examined, using tight binding extended Hueckel calculations on a three-layer model slab. We have studied various adsorption sites. Calculations indicate that PF3 should be preferentially bound to the onefold on-top Ni sites, with P-F bonds azimuthally oriented over neighboring Ni atoms. PF2 is indicated to bind in a 'perpendicular' manner at a twofold bridging site or possibly at a threefold site; and PF to the threefold hollow sites. These calculations are in agreement with experimental findings. PF3 remains a sigma donor and a pi acceptor (through backbonding) on the surface; in the bonding of PF2 and PF the pi interaction is more important. Keywords: Surfaces, Phosphines, Electronic structure, Reprints, Ligands, Transition elements. (JG)