发光性质可调的金属-有机骨架材料 的合成及发光性质

以对苯二甲酸(H₂BDC)为配体,以锌为中心离子,采用沉淀法合成了具有一维结构的金属配合物 纳米晶,将化合物分散到不同浓度的8-羟基喹啉(8-Hq)溶液中,得到系列配位聚合物 。分别用FT-IR和XRD对目标产物的结构进行了表征。固态发光性质研究显示: 及其配位聚合物具有强的发光,配位聚合物随着8-Hq量的增加,其发光发射光谱有规律地红移,表明该配位聚合物能够通过改变8-Hq与骨架材料间的量的比实现对材料发光性质的调控。

Synthesis and Fluorescent Property of Metal-organic Frameworks with Tunable Fluorescence

Nanoporous metal-organic frameworks (MOFs) materials have been developed rapidly in recent years. The materials were constructed of organic ligands and metal ions. Multi-functional MOFs materials were designed by different organic ligands and metal ions, i.e. Zn2+ and 1,4-benzenedicarboxylic acid (H2BDC) can assembled to 1-D,2-D,3-D MOFs materials. They can be applied in gas storage,chiral separation,catalysis,molecular magnet and photoelectric material. However, only a few examples of porous MOFs with open metal sites have been illustrated for their functional properties, mainly because of the difficulty of constructing robust MOFs that hold open metal sites.In this paper, H2BDC and Zn2+ are chosen to synthesize 1-D MOF by using precipitation method, which is a facile and environmentally friend method. A series of coordination polymers, i.e. , were obtained by substitution and adsorption in the reaction of with different content of 8-hydroxyquinoline. Their structures were characterized by XRD and FT-IR . The results of XRD show no structure change in low content of 8-hydroxyquinoline. How-ever, when n(8-Hq) ∶ n( )=1 ∶ 20, the peaks of XRD have obviously difference to standard chart. It may be attribute to 8-Hq substituting coordination water. When n(8-Hq) ∶ n( )﹥1 ∶ 1, coordination water was substituted whole, and the adsorption effects is dominant. TEM images showed nanocrystals of are grown with increase of 8-Hq concentration.Nanocrystals of and exhibit strong solid state fluorescence properties. Fluorescence emission spectra revealed that the wavelength of maximum emission (λem) redshifts regularly with increasing the amounts of 8-hydroxyquinoline, λem redshifts from 376 nm to 428 nm with n(8-Hq) ∶ n( )=1 ∶ 200~1 ∶ 80. Changing the ratio of n(8-Hq) ∶ n =4 ∶ 1, λem redshifts to 528 nm. These phenomena were explained rationally by fluorescence area integral. The results suggest that emission spectrum can be tuned by varying ratio of to 8-hydroxyquinoline. These kind of metal-organic frameworks have potential applications for display devices, fluorescence imaging, and fluorescence label, and so on.