PF3, PF2, AND PF ON NI(111) - THEORETICAL ASPECTS OF THEIR CHEMISORPTION

The chemisorption of PF3, PF2, and PF on Ni(111) is examined, using tight binding extended Hückel 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. PF 2 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 σ donor and a π acceptor (through backbonding) on the surface; in the bonding of PF2 and PF the π interaction is more important. © 1990 American Institute of Physics.