Synthesis and properties of new liquid crystals derivatives of 2,7-diethynyl-9,9-dihexylfluorene

We present a synthetic strategy to obtain a 2,7-diethynyl-9,9-dihexylfluorene-based framework which we modified with aromatic rings and terminal alkoxy chains to obtain new liquid crystals. Two of the three series synthesised present mesomorphic behaviour with the characteristic Schlieren texture of nematic phases. The presence of fluorene gave rise to liquid crystals which emit blue light. Thermal and electrochemical stability were investigated, revealing high decomposition temperature and a wide potential application window, respectively. Computational calculations were performed on the optimised geometries of compounds in order to compare experimental and theoretical properties. The optical, electrochemical and theoretical band gap were determined and compared.