2015 Volume 88 Issue 11 Pages 1584-1590
The ligand coupling reaction (LCR) of hypervalent pentacoordinate antimony compounds (ArnTol5−nSb; Ar = p-trifluoromethylphenyl, Tol = p-methylphenyl; n = 0–5) was analyzed via the long-range-corrected density functional theory. Although previous experimental or computational investigations have suggested apical–apical or equatorial–equatorial coupling of ArnTol5−nSb compounds, the present results lead to apical–equatorial coupling. The biased experimental ratios of the coupling products, which were grounds for apical–apical coupling, can be explained by the stability of the transition-state (TS) structure for the apical–equatorial coupling, where n–π* interaction plays an important role to the stabilization. We further investigated the potential energy surface of H5Sb, for which the intrinsic reaction coordinate (IRC) from the TS structure for LCR indicates the equatorial–equatorial coupling. It is found that the valley-ridge transition occurs along the IRC near the TS structure and the transverse vibrational mode with imaginary frequency, orthogonal to the IRC, directs to the reactant structure corresponding to the apical–equatorial coupling.
This article cannot obtain the latest cited-by information.