Synthesis and photophysics of novel 8-hydroxyquinoline aluminum metal complex with fluorene units

A novel luminescent metal complex, (MQPF)3Al2, with 8-hydroxyquinoline aluminum and 9,9-diphenylfluorene was synthesized. The optical properties were investigated by UV-vis absorption and fluorescence emission spectra. The results showed that the luminescence quantum yield of (MQPF)3Al2 was 0.612 in THF and it emitted red light with the band gap of 3.18 eV estimated from the onset absorption. The emission spectra exhibited obvious solvent effect. With the increase of polarity of solvents the fluorescence spectra changed obviously and appeared blue shift about 60 nm at room temperature. In addition, the light-emitting can be quenched by both electron donor (N,N-dimethylaniline) and electron acceptor (Fullerene), where the processes followed the Stern-Volmer equation. However, when adding 1,4-dicyanobenzene (DCB) which was a stronger electron acceptor to the solution of (MQPF)3Al2, the fluorescent intensity was increased.