Precise Synthesis of Optically Active and Thermo‐degradable Poly(trifluoromethyl methylene) with Circularly Polarized Luminescence

Developing high performance and environment‐friendly fluoropolymers is greatly desired. In this work, we found that 2‐diazo‐1,1,1‐trifluoroethane can be polymerized by air‐stable alkyne‐palladium(II) catalysts following a living polymerization mechanism, affording a fluoropolymer, poly(trifluoromethyl methylene) in high yield with controlled molar mass and low dispersity. This polymer bears trifluoromethyl on every main chain atom and thus has good resistance to chemical corrosion, high hydrophobicity, and excellent dielectric constant with low dielectric loss. Due to the steric hindrance between the trifluoromethyl pendants, the synthetic poly(trifluoromethyl methylene) can twist into a stable helix. The one‐handed preferred helices synthesized using chiral PdII‐catalysts exhibit high optical activity and circularly polarized luminescence. Remarkably, such polymer can be completely degraded to (E)‐1,1,1,4,4,4‐hexafluorobut‐2‐ene at high temperatures (>280 °C). Additionally, taking advantage of the living chain end, the polymer can be further modified. Living polymerization of 2‐diazo‐1,1,1‐trifluoroethane gives environmental friendly poly(trifluoromethylmethylene) in high yield with controllable molar mass and low dispersity, which twisted into stable helix with clear circularly polarized luminescence. The high fluorine content results in high hydrophobicity, good resistance to chemical corrosion, high dielectric constant with low dielectric loss.