Abstract: A monomer has been designed, synthesized and polymerized with [Rh(nbd)Cl]2-Et3N(nbd:2,5-norbonadien) catalyst. The liquid crystalline polyacetylene bearing chiral terphenyl mesogen {—[(CH=C(CH2)3OCO—terphenyl(OR*)2]n—, R*=(S)-2-methylbutyl, (PAM3OCO(TPh)(OR*)2)} was obtained in high molecular mass(mass-average relative molecular mass is 30300). The monomer shows enantiotropic smectic C(SmC*) phase by introducing chiral groups and terphenyl mesogen, while its corresponding polymer exhibits enantiotropic smectic A(SmA*) liquid crystalline behavior. The “jacket effect” induced by the terphenyl mesogen linked at mass center position endows the polymer with high thermal stability(356 ℃), high photoluminescence and aggregationinduced emission enhancement(AIEE). Upon UV irradiation, the light-emitting of the solid state of the polymer fabricated at room temperature is stronger than that of the dilute solution, and its internal quantum efficiency and external quantum efficiency are 0.214 and 0.023, respectively. Photoluminescence of the polymer quenched from the liquid crystalline state of is obviously stronger and red-shifted than those of the solution and thin film states under excitation at the ultraviolet wavelength.

Key words: Polyacetylene, Liquid crystal, Chirality, Photoluminescence, &, ldquo, Jacket effect&, rdquo