Activation of ethane C-H and C-C bonds by gas phase Th+ and U+: a theoretical study.

Two different approaches of density functional theory were used to analyze the C-H and C-C bond activation mechanisms during the reaction of bare Th(+) and U(+) ions with ethane. We report a complete exploration of the potential energy surfaces taking into consideration different spin states. According to B3LYP/SDD computations the double dehydrogenation of C(2)H(6) is thermodynamically favorable only in the case of Th(+). It is shown that the overall C-H and C-C bond activation processes are exothermic in the case of Th(+) and endothermic for U(+). In both cases, the C-C insertion transition state barrier exceeds the energy of the ground state reactants, preventing the observation of these species under thermal conditions.