Solid-state red emission of boron–fluorine complexes with extended π-conjugated structure

Two unique boron–fluorine complexes bearing extended conjugated structure were designed and synthesized facilely. These compounds absorb in visible region and emit red light in solutions with large Stokes shift. However, emission red-shift was observed with concentration increasing, showing typical J-aggregated fluorescence. Due to the J-aggregate formation, red emissions were observed in solid state for both compounds.