Aggregation behavior of α-substituted dibenzoylmethanatoboron difluoride complex with various alkyl groups in water/acetone mixtures

Abstract Dibenzoylmethanatoboron difluoride complexes (BF2DBM) exhibit aggregation-induced emission (AIE) properties by introducing a methyl group at the α-position of the dioxaboroline ring. In this study, we synthesized α-substituted BF2DBM derivatives with alkyl groups and evaluated their photophysical and AIE properties as a function of water fraction (fw) in water/acetone mixtures. The aggregation behavior of the BF2DBMs differed depending on fw, although they exhibited AIE independently of the alkyl groups. The fw dependence suggested that the alkyl groups exhibit hierarchical aggregation behavior, indicating that the alkyl groups affect the intermolecular stacking pattern based on the X-ray crystallography, leading to the difference in the fluorescence properties of the crystals.