A theoretical investigation of the reaction mechanisms for C-H and C-C bond activation processes in the reaction of Ni with cycloalkanes Cn H2n(n = 3~7) is carried out.For the Ni + Cn H2n(n = 3,4) reactions,the major and minor reaction channels involve C-C and C-H bond activations,respectively,whereas Ni atom prefers the attacking of C-H bond over the C-C bond in Cn H2n(n = 5~7).The results are in good agreement with the experimental study.In all cases,intermediates and transition states along the reaction paths of interest are characterized.It is found that both the C-H and C-C bond activation processes are proposed to proceed in a one-step manner via one transition state.The overall C-H and C-C bond activation processes are exothermic and involve low energy barriers,thus transition metal atom Ni is a good mediator for the activity of cycloalkanes Cn H2n(n = 3~7).
