Structure and bonding in triorganotin chlorides: a perspective from energy decomposition analysis.

The Sn-Cl chemical bond of four organotin halides (MeSnCl, EtSnCl, BuSnCl, and PhSnCl) was studied by using relativistic density functional theory in combination with a quantitative energy decomposition analysis to explain the formation of charged species. The σ orbital is the dominant contributor to the stabilization of the Sn-Cl bond, and the π-orbital interactions also have a significant contribution to the stabilization of PhSn cation when the aromatic groups are bonded to the tin atom. The aromaticity of the phenyl groups delocalizes the positive charge, donating electrons to tin atom by conjugation.

Reactivity and regioselectivity in reactions of methyl and ethyl azides with cyclooctynes: activation strain model and energy decomposition analysis.

The structures and energies for the Huisgen 1,3-dipolar cycloaddition reactions of methyl and ethyl azides with some cyclooctynes and dibenzocyclooctynes were computed at the B3LYP/6-311++G(d,p) level. The activation strain model (ASM) and quantitative molecular orbital (MO) theory were used to investigate the reactivity and regiochemistry in these reactions. The energy decomposition analysis (EDA) was used to identify the intrinsic electronic factor that lead to the preferential formation of 1,7-regiochemistry products.