Adjustable 2-cyano-3,4-difluoro-1H-pyrrole-based luminescent liquid crystals: Synthesis, properties and substituent effect

A series of new D-π-A type luminescence liquid crystals (LLCs) with fluorinated pyrrole, 2-cyano-3,4-difluoro-1H-pyrrole (CN-2F), as key acceptor has been prepared at first time. These wheel type molecules exhibit efficient fluorescence in solution/solid state and display typical mesophase behavior. The emitting color of compounds could be modify from blue to green when variation of the end substituents on terminal benzene, which offer a simple approach to obtain the adjustable LLCs.64