Blue fluorescence from N,O-coordinated BF complexes having aromatic chromophores in solution and the solid state.

We prepared amide-heterocycle (HC) compounds having various aromatic π-electron systems (Ar), such as phenyl, naphthyl, furyl, thienyl and phenanthryl moieties, and converted them as ligands to difluoroboronated complexes, Ar@HCs. Blue fluorescence from Ar@HCs was observed in solution and the solid state, and the fluorescence quantum yields (Φ) and lifetimes (τ) were determined. The Φ values in CHCl were as small as 0.