Triphenylene-containing acetylenes with one or three methylene units as spacers and the corresponding mesogen-jacketed liquid crystalline polyacetylenes (MJLCPAs) were designed and synthesized, the mesomorphic properties and phase behaviors of the monomers and novel side-chain liquid crystalline polymers were investigated. The monomers [HC^C(CH 2 ) m C 18 H 6 (OC 6 H 13 ) 5 ; m ¼ 1, 3] are prepared by consecutive etherization, coupling, and etherization reactions, and the chemical structures were confirmed by mass spectroscopy and 1 H/ 13 C-NMR. The phase behaviors of the monomers were investigated by differential scanning calorimetry (DSC), polarized light microscopy (PLM), and wideangle X-ray diffraction (WAXD). The results show that both of the monomers form a hexagonal columnar liquid crystal phase at room temperature. The monomers are polymerized using [Rh(nbd)Cl] 2 as catalyst and producing soluble polymers in the yields of 55% and 52%, respectively. The chemical structures and phase behaviors of the two polymers are characterized and evaluated by IR, NMR, TGA, DSC, and WAXD analyses. Both of the two polymers show enhanced thermal and chemical stability with thermal decomposition temperatures up to higher than 340 C due to the protection of the "jacketed effect" of the side-chain triphenylenes wrapped around the rigid polyacetylene main-chain. The polymers adopt a columnar shaped structure and self-organized into hexagonally packed columnar phase. The relative electron density maps of the columnar structure are also reconstructed.

The luminescent liquid crystals (LLCs) are expected to solve the conflicts between the aggregation caused quenching and the requirement of aggregation or self-organization for LCs. Herein, we developed a new strategy of applying aggregation-induced emission (AIE) phenomenon to the molecular design of LCs towards LLCs. In this report, a calamitic liquid crystal based on tolane with AIE characteristics was successfully synthesized and the chemical structure was characterized by 1 H, 13 C NMR, and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) high-resolution mass spectra. The fluorescence behavior was studied by fluorescence spectroscopy and the liquid crystal phase behaviors were investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM). The crystal structure was obtained by X-ray diffraction crystallography with P1 space group. Results demonstrated that the sample was AIE active and the LC phases sequence during cooling was nematic, smectic C and smectic B phase.

The bromo-substituted main chain liquid crystal polyesters poly(3-bromo-4-oxybiphenylene-4'-carbonyl) (PBOBC) and poly(5-bromo-6-oxy-2-naphthoyl) (PBONY) have been polymerized as lamellar single crystals using the confined thin film melt polymerization (CTFMP) technique. Electron diffraction indicates a triclinic (pseudo-orthorhombic) unit cell with a = 12.71, b=3.85, c= 10.50A, a=P =y=90° for PBOBC and a monoclinic unit cell with a= 13.02, b=4.06,c= 17.15 A,p = 101" for PBONY. The crystal structures of the two polymers have been simulated by the Cerius' program and are suggested to have space group P1 for PBOBC and space group P12,Icl for PBONY. DSC measurements indicate that these two bromosubstituted fully aromatic polyesters have crystal-mesophase transition temperatures (Tk.m = 389 "C for PBOBC and 429 "C for PBONY) with TGA indicating the onset of degradation at similar temperatures (400 and 420 "C). The Tk.m are between those of the corresponding non-substituted and phenyl-substituted aromatic polyesters. Possible reasons for the Tk.m differences are considered in detail.