If there is an electropositive substituent (e.g. –SiR, –SnR, –HgR, etc.) at the β-position of carbocation, the positive charge could be stabilized which is also due largely to the stereoelectronic effect (illustrated below using –SiR3 as an example). The orientation of the two interacting orbitals can have a significant effect on the stabilization effect (σ(C–Si) → empty p orbital), where antiperiplanar (180°) > perpendicular (90°) > syn (0°).