A DFT study on the oxidation of cyclotrisilene by nitrous oxide: the σ- and π-bonds reactivity

Abstract

The chemistry of heteroatom analogues of cyclopropane derivatives has been receiving considerable interest because of their unexpected reactivities. Herein, the density functional theory (DFT) method was applied to understand reactivity and selectivity of sigma (σ) and pi (π) bonds in methyl and aryl (2,4,6-iPr3C6H2)-substituted cyclotrisilenes, as silicon analogue of cyclopropane, for the reaction with nitrous oxide. The DFT calculations at the APFD/def2-TZVPP level of theory show that three types of isomers with Si3O subunit can be considered as potential products for methylated system. The further DFT calculations on the proposed reactions favor the π-bond reactivity of the methyl-substituted cyclotrisilene to yield a structure that adopted the cyclic planar-trans geometry with the lower energy barrier and considerably high exergonic nature. Moreover, π-bond reactivity of the cyclotrisilene with aryl group promotes the formation of the folded isomer of the planar-trans structure with only 0.3 kcal mol−1 energy gap at the B3LYP-D3/6-31G(d,p) level of theory. The theoretical results provide a crucial guide for the reaction to be tackled experimentally.