The influence of multiple alkyl chains on mesomorphic and photophysical properties of diphenylacrylonitrile liquid crystals

For the purpose of studying the influence of the number of alkyl chains on mesomorphic and photophysical properties of aggregation-induced emission liquid crystals, the novel diphenylacrylonitrile derivatives 6–9 with 2–5 alkyl chains were prepared in yields of 80%–86%. The studies suggested that the number of alkyl chains influenced greatly on both mesomorphic properties and aggregation-induced emission fluorescence. The four or five alkyl chains on diphenylacrylonitrile liquid crystals were favourable for the ordered hexagonal columnar mesophase. The three or four alkyl chains contributed to high fluorescence. The four alkyl chains on diphenylacrylonitrile derivatives were the optimised number for producing the ordered columnar liquid crystalline phase and high fluorescence.