Synthesis And Self-Assembly Of Cruciform Triblock Liquid Crystal Oligomers Containing Anthracene Unit

Rod-coil molecules, consisting of a flexible and a rigid block, have a strong affinity to self-organize into various supramolecular nanostructures in the bulk state. Self-assembly of rod-coil molecules are widely studied due to their remarkable application prospects as good light, electricity, functional magnetic advanced functional nanomaterials and molecular devices. In this paper, two series of rod-coil molecules were designed successfully synthesized, the molecular structures are characterized by NMR and matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectroscopy. The self-assembling behaviors of these molecules were investigated by means of differential scanning calorimetry (DSC), polarizing optical microscopy (POM), X-Ray diffraction (XRD), UV-vis absorption and fluorescence spectra in the bulk state.Firstly, cruciform molecules consist of9,10-bis(arylethynyl)anthracene as a rigid rod segment connecting poly(ethylene oxide)(PEO) with different degree of polymerization (DP) and alkoxy as coil segments were synthesized, characterized, and their self-assembly behavior was investigated in the bulk state. The result indicates that some of the molecules self-organize into oblique columnar structures, and as the temperature increased, transform into nematic phase in the liquid crystalline phase; Some the molecules self-assemble into lamellar structure in the crystalline phase at room temperature. The fluorescence quantum yield (Φf) of every compound is obtained through the calculation of spectral analysis, showing they are strong fluorescence compound.In addition, a pair of isomers were synthesized. These two molecules consist of conjugated rod segments, which are composed of phenylene, biphenylene and carbon-carbon triple bond (C≡C), and PEO with a degree of DP of7as coil segments. Structural isomers1and2self-assemble into lamellar structure in the crystalline state. In the liquid crystalline phase, molecule1self-organizes into hexagonal perforated lamellar structure, while, molecule2self-assembles into lamellar structure.