Photoluminescence properties of new BF2 complexes with pyrazolone ligands: Dependence on volume and electronic effect of substituents

Novel fluorine–boron complexes with donor–acceptor architecture in which pyrazoline-1,3-diones were chosen as electron donors have been synthesized and well characterized. Correlation of the luminescence properties of the complex 2c and its crystal structures was discussed. Well-ordered molecular packing in the crystal results in strong charge transfer interactions characterized by long excited-state lifetime. These fluorine–boron complexes show photophysical properties highly dependent on the solvent polarity and aggregation states. The substituents on the pyrazoline were found to have a significant impact on the solid-state luminescent properties. As a result, some significant differences in charge transfer modes were observed in the solid state among these complexes.

Graphical abstractNovel fluorine–boron complexes with donor–acceptor architecture have been synthesized and well characterized. The substituents on the pyrazoline were found to have a significant impact on the luminescence properties. As a result, some significant differences in charge transfer modes were observed in the solid state among these complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide