Ab initio thermochemistry of the hydrogenation of hydrocarbon radicals using silicon-, germanium-, tin-, and lead-substituted methane and isobutane
Temelso, B.; Sherrill, C. D.; Merkle, R. C.; Freitas, R. A. Ab Initio Thermochemistry of the Hydrogenation of Hydrocarbon Radicals Using Silicon-, Germanium-, Tin-, and Lead-Substituted Methane and Isobutane. J. Phys. Chem. A 2007, 111 (35), 8677-8688.
A series of reactions of the type Y· + XH4 → YH + ·XH3 and Y'· + HX(CH3)3 → Y'H + ·X(CH3)3, where Y = H, CH3; Y' = CH3, C(CH3)3; and X = Si, Ge, Sn, Pb are studied using state-of-the-art ab initio electronic structure methods. Second-order Møller-Plesset perturbation theory; the coupled-cluster singles, doubles, and perturbative triples method; and density functional theory are used with correlation-consistent basis sets (cc-pVNZ, where N = D, T, Q) and their pseudopotential analogs (cc-pVNZ-PP) to determine the transition-state geometries, activation barriers, and thermodynamic properties of these reactions. Trends in the barrier heights as a function of the group IVA atom (Si, Ge, Sn, and Pb) are examined. With respect to kinetics and thermodynamics, the use of a hydrogen attached to a group IVA element as a possible hydrogen donation tool in the mechanosynthesis of diamondoids appears feasible.
Journal of Physical Chemistry A