Poly(p-phenyleneethynylene)s by alkyne metathesis.

Alkyne metathesis was effected by mixtures of Mo(CO)(6) and phenols at elevated temperatures based on an improved version of the method reported by Mortreux and Mori. When propynylated arenes are subjected to these reaction conditions, the formation of diarylalkynes is often quantitative and likewise allows the synthesis of alkyne-bridged macrocycles and polymers of high molecular weight. Alkyne metathesis made high-molecular weight poly[p-(dialkylphenylene)ethynylene]s (PPEs) accessible that show promise as active layers in organic semiconductor devices.