Design and facile synthesis of quinazolinone-based full color-tunable boron difluoride dyes: Efficient solvent/solid-state emission and bioimaging application.

To develop the construction of small organic fluorophores with full color-tunable luminescence through facile synthesis is highly imperative for applications. Herein, novel quinazolinone based BF 2 complexes (2a-2g) have been designed and synthesized. By modifying the structure of quinazolinone ligand, the synthesized boron difluoride dyes exhibited fluorescence in the almost full-color range of the visible spectrum (∼450–750 nm) both in solution and solid-state with good to excellent quantum yield. The influence of three electron donating substituents, such as methyl, methoxy and N,N -dimethylamino group, in quinazolinone core on the photophysical properties of BF 2 compounds was discussed. The position of substituent in quinazolinone has some influence on the emission efficiency, but has little influence on the absorption and emission of BF 2 compounds. Finally, 2g showed good cell compatibility and living cell imaging property. [Display omitted] • A novel quinazolinone-based BF 2 fluorescent dyes have been synthesized. • The BF 2 dyes exhibited fluorescence in full-color range (∼450–750 nm) both in solution and solid-state. • The highest solution fluorescence QY up to 0.99, the QY in solid state up to 0.50 • 2g showed bright deep red to NIR fluorescence in B16 cells. [ABSTRACT FROM AUTHOR]