title: Kinetics of substituted silylene addition and elimination in silicon nanocluster growth captured by group additivity.
abstract: Accurate rate coefficients for 40 bimolecular substituted silylene addition reactions for silicon hydrides containing up to nine silicon atoms are calculated using the G3//B3LYP method. The overall reactions exhibit two steps: the reactants first meet to form an adduct, which then converts into a saturated silicon hydride. Values for the single-event Arrhenius pre-exponential factor, A, and the activation energy, E(a), are calculated from the G3//B3LYP rate coefficients corrected for internal rotations, and a group additivity scheme is developed to predict A and E(a). The values predicted by group additivity are more accurate than structure-reactivity relationships currently used in the literature, which rely on representative A values and the Evans-Polanyi correlation. The structural factors that have the most pronounced effect on A and E(a) are considered, and the presence of rings is shown to influence these values strongly.
authors.affiliation: Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL 60208-3120, USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Adamczyk
authors.forename: Marie-Françoise
authors.initials: MF
authors.lastname: Reyniers
authors.forename: Guy B
authors.initials: GB
authors.lastname: Marin
authors.forename: Linda J
authors.initials: LJ
authors.lastname: Broadbelt