ASSOCIATION REACTIONS OF NICKEL ATOMS WITH CARBON-MONOXIDE AND ALKENES AT ROOM-TEMPERATURE - BINDING-ENERGY OF NIC2H4

We report a kinetic study of association reactions of nickel atoms with carbon monoxide, ethene, propene and 1-butene in carbon dioxide buffer gas in the pressure range 1-600 Torr at 296 K. RRKM theory is used together with results of previous ab initio electronic structure calculations to interpret association rate coefficients in terms of binding energies of 1:1 complexes. The binding energy of NiC2H4 at 0 K is estimated as 35.5 +/- 5 kcal mol-1. The role of excited electronic states of the complexes in the association reactions is briefly discussed.