关键词: 烷烃, 反应机理, 丙烷, 甲烷, 镍离子

The reaction of Ni^+ with propane has been studies extensively using density functional theory. The detailed information regarding the mechanism and energetics of CH4 elimination on the potential energy surface of [Ni, C3, H8]^+ has been obtained at B3LYP/6-311++g(3df, 3pd) level of theory. The present study indicates that the CH4 elimination in the reaction of Ni^+ with propane undergoes two elementary steps, namely, the initial C—C bond activation in propane mediated by Ni^+ and the subsequent isomerization of the inserted intermediate. Ni^+ inserting into the initial primary C—H bond cannot results in the elimination of CH4, which is in contrast to the early postulated mechanism. After the C—C inserted species are formed on the potential energy surface, three reaction channels are open, which result in the elimination of CH4. The relative energy of the energetically most favored transition state is found to be 9. 18kJ/mol above the entrance channel. The heat of reaction for Ni^+C3H8 → Ni(C2H4)^++CH4 is calculated to be 127.85kJ/mol. This result is in good agreement with the experimental finding, a value of 106.13kJ/mol.

Key words: ALKANE, REACTION MECHANISM, PROPANE, METHANE, NICKEL ION