Stimuli Responsive Silylene: Electromerism Induced Reversible Switching Between Mono‐ and Bis‐Silylene
Ravi Yadav, Xiaofei Sun, Ralf Köppe, Michael T. Gamer, Florian Weigend, Peter W. Roesky
Abstract
Abstract Electromerism is a very well‐known phenomenon in transition metal chemistry. In main group chemistry, this concept has only started getting attention recently. We report stimuli responsive low‐valent silicon compounds exhibiting electromerism. A mixed‐valent silaiminyl‐silylene 1 , [ L Si−Si(NDipp) L ] ( L= PhC(N t Bu) 2 ), was synthesized in a single step from amidinate‐chlorosilylene. Compound 1 has two interconnected Si atoms in formally +I and +III oxidation states. Upon treatment with Lewis acidic Cu I X (X=mesityl, Cl, Br, I), electron redistribution occurs resulting in the formation of [{ L Si(NDipp)Si( L )}−CuX], in which both silicon atoms are in the +II formal oxidation state. Removal of the copper center from [{ L Si(NDipp)Si( L )}−CuX] by using a Lewis basic carbene led to reformation of the precursor [ L Si−Si(NDipp) L ]. Thus, the process is fully reversible. This showcases the first example of Lewis acid/base‐induced reversible electromerism in silicon chemistry.