Synthesis and Structure of a Stable Bis(methylene)‐λ⁴‐sulfane

Abstract

Bis(methylene)‐λ⁴‐sulfane 1, a >C=S=C< heterocumulene, was obtained as a red crystalline solid from the reaction between elemental sulfur and a carbenoid that contains sterically demanding silylalkyl groups. Under atmospheric conditions, and even at elevated temperatures, 1 exhibits extraordinary stability. The molecular structure and electron‐density distribution of 1 were analyzed by single‐crystal X‐ray diffraction analysis, which revealed a bent C=S=C geometry with C=S=C π‐bonds. These results, combined with those of variable‐temperature NMR measurements and theoretical calculations suggest a slow rotation of the S=C moieties in 1, the stability and structure of which were further examined by theoretical calculations.