Development of Hydrogen-Bonded Dimer-Type Photoluminescent Liquid Crystals of Fluorinated Tolanecarboxylic Acid

Functional molecules possessing photoluminescence (PL) and liquid-crystalline (LC) behaviors, known as photoluminescent liquid crystals, along with a small molecular structure, have attracted significant attention. Fluorinated tolane skeletons are π-conjugated structures, which promising candidates for such functional molecules. These structures were revealed to exhibit strong PL in solid state but no LC behavior. Based on report hydrogen-bonded dimer-type of carboxylic acid, this study, we designed synthesized series fluorinated tolanecarboxylic acids (2,3,5,6-tetrafluoro-4-[2-(4-alkoxyphenyl)ethyn-1-yl]benzoic acids) PLLC Evaluation the behavior that longer alkoxy chain than butoxy exhibited nematic Additionally, showed intense solution crystalline states. Notably, acid an aggregated structure phase also slight blue shift maximum wavelength compared state. The present exhibiting characteristics single molecule can be applied thermoresponsive materials, thermosensor.