Synthesis, characterization and properties of furan-containing difluoroboron complexes

Abstract

Novel difluoroboron β-diketonate complexes F1–F4 bearing a furan unit were synthesized and fully characterized. The effects of different substituents on the photoluminescence and redox properties of these new BF₂ complexes were investigated systematically. The absorption and emission maxima of complexes F1–F4 were red-shifted compared to those of reference substance F0. Among them, the complexes F2 with a rigid naphthalene moiety and F3 with an electron donating methoxyl group demonstrated stronger fluorescent emission intensity, much higher quantum yields and longer lifetime values relative to other complexes. Cyclic voltammetry measurements revealed the reversible reduction waves of these BF₂ complexes. DFT calculations supported the structural and spectroscopic data and confirmed the compositions of frontier molecular orbitals in the BF₂ complexes. These new complexes exhibited different emission colors in solvent and might have potential applications in emitting devices.