A Fully Substituted 3‐Silolene Functions as Promising Building Block for Hyperbranched Poly(Silylenevinylene)

A 3‐silolene derivative, 2,2,5,5‐tetrakis(dimethylsilyl)‐1,1‐dimethyl‐3,4‐diphenyl‐3‐silolene (TDMSHS), is first synthesized and characterized by X‐ray diffraction crystallography and spectroscopic methods. Hydrosilylation polymerization of TDMSHS with 1,1‐dimethyl‐2,5‐bis(4‐ethynylphenyl)‐3,4‐diphenylsilole in the presence of Karstedt's catalyst generates a stereoregular silole‐containing hyperbranched poly(silylenevinylene) ( hb ‐SPSV) with a high molecular weight ( $\overline{M}_{\rm w}$ = 146 000, $\overline{M}_{\rm w}$ / $\overline{M}_{\rm n}$ = 1.5) in high yield (≈95%). hb ‐SPSV exhibits excellent thermal stability and strong fluorescence, and the emission of its aggregates in aqueous mixture can be quenched efficiently by picric acid with large quenching constants K SV up to 414400 M −1 .