Thermotropic Polymethacrylate Bearing Sulfonylbenzoxazole-Based Multifunctional Photoactive Mesogen

For the multifunctional liquid crystalline medium with high chromophore content, a thermotropic polymethacrylate (PBBS) bearing monolithic photoactive mesogen was designed and synthesized on the basis of semiempirical quantum calculation. PBBS showed phase transition sequence of I−222 °C−SmA−169 °C−SmC−154 °C−SmX on cooling. Phase transition in the PBBS film could be correlated with the birefringence change and H-aggregate formation monitored as a function of temperature. The multifunctional mesogenic pendant, 2-biphenyl-5-sulfonylbenzoxazole, provided strong blue fluorescence and electroluminescence, large second-order optical nonlinearity, and intrinsic photoconductivity to the novel photoactive liquid crystalline polymer PBBS.