Structures and Stabilities of Three-Membered Rings Containing a Hypervalent Atom

摘要: We investigated the structures and stabilities of three-membered rings (X = Si, P, S; Y CH2, NH, O; n 2 or 3) containing a hypervalent atom (X) disclosed their origins by developing applying an electron-pair bond model for molecules. For pentacoordinated Si P atom, (ap, eq) isomers with ring bonds in apical equatorial positions are local minima, while (eq, both transition states pseudorotation reactions due to high strains. In contrast, tetracoordinated S minima. The species less strained than ones because effect lone pair on X giving rise antibonding properties electron delocalization between geminal X. Moreover, more surprisingly stable ...