Abstract:

Two novel ligands, 3,5-bis(4-(8-hydroxyquinoline-5-methyleneamino)phenoxy)octyl benzoate(B8HQO) and 3,5-bis(4-(8-hydroxyquinoline-5-methyleneamino)phenoxy)hexadecyl benzoate(B8HQH) were synthesized and coordinated with Zn(Ⅱ) and Al(Ⅲ), respectively, to get the four corresponding coordination polymers(B8HQO-Zn, B8HQH-Zn,B8HQO-Al and B8HQH-Al). Their structures and properties were characterized by elemental analysis, Fourier transform infrared spectrometer(FTIR), UV-visible absorption(UV-Vis), proton nuclear magnetic resonance spectroscopy(¹H NMR), inductively coupled plasma optical emission spectroscopy(ICP-OES), thermal gravimetric analyzer(TGA) and fluorescence spectroscopy. The results indicate that compared with B8HQO and B8HQH, the solubility of the four coordination polymers is reduced, but can be partially soluble in N,N-dimethyl formamide(DMF), N,N-dimethyl acetamide(DMAC), dimethylsulfone(DMSO), N-methylpyrrolidone(NMP). The 5% mass loss temperatures of zinc and aluminum coordination polymers at around 378 and 364 ℃, respectively, show that they have good thermal stability. The fluorescence measurement shows that they emit green luminescence at 478~502 nm in DMF solution(3×10^-5 mol/L) and their fluorescence quantum efficiency is 28%~37%. The four coordination polymers emitting strong green luminescence at 528~553 nm in the solid state show that they have good luminescent properties.

Key words: bis-8-hydroxyquinoline, zinc, aluminum, coordination polymer