A density functional study of [M(PH_3)_2(#eta#~2-C_2X_4)] alkene complexes for the Group 10 metals Ni, Pd, Pt: the effect of electron-attracting substituents

摘要

Density functional calculations have been performed for [M(PH_3)_2(C_2X_4)] complexes with M = Ni, Pd or Pt and X = H, F or CN to study the effect of electron-atracting substituents on the metal-olefin bonding. The optimised geometries have been found to be in good agreement with experimental crystal structure data. The electronic structure has been analysed in terms of the Chatt-Dewar-Duncanson model and the contribution from #pi# back donation was found to dominate over that from δ domation for both ethylene and substituted ethylene complexes. Reliable values have been calculated for the metal-olefin bond dissociation energies and compared with the available experimental data.