Design, Synthesis And Property Study Of Multifunctional Luminescent Materials Based On Metal-Organic Frameworks

Metal-organic frameworks (MOFs) have diverse topologies with aesthetic beauty as well as potential applications in numerous areas, for instance gas storage, sensing, catalysis, drug delivery, and so on. In recent years, MOFs have been especially promising as multifunctional luminescent materials and received considerable attention. Both the inorganic and organic moieties in MOFs can provide the platform to generate luminescence, and metal-ligand chargetransfer-related luminescence within MOFs can add another dimension to luminescent functionalities. Furthermore, the highly regular channel structures and controllable pore sizes of MOFs permit their application in some guest-molecule adsorption, which can also emit and/or induce luminescence. However, it is still a significant challenge for targeted "design" and "control" tailor-made compounds with expected structures and multifunctional properties in synthesis chemistry and materials science.In this dissertation, we introduce lanthanide into MOFs to construct tunable luminescent lanthanide-based MOFs (LnMOFs). Meanwhile, we design and synthesize a ligand with aromatic ? rings and nitrogen atoms with lone-pair electrons, which may help to adjust the position of ligands to provide intraligand interactions and promote luminescent character to detect explosives. In addition, we take advantage of a common ligand to prepare MOF and investigate its application in the separation of dyes and the detection of ion.1. A new family of heterometal-organic frameworks has been prepared by two synthesis strategies, in which IFMC-26 and IFMC-27-La are constructed by self-assembly and IFMC-28 is obtained by stepwise synthesis based on the metalloligand. IFMC-26 is a (3,6)-connected net and IFMC-27-La is a (4,8)-connected 3D framework. The metalloligands are connected by binuclear lanthanide clusters giving rise to a 2D sheet structure in IFMC-28. Notably, tunable luminescence of IFMC-26 and IFMC-28 has been obtained by changing the molar ratios of raw materials. Owing to the porosity of IFMC-26, Tb3+@IFMC-26-Eu and Eu3+@IFMC-26-Tb are obtained by postencapsulating Tb3+and Eu3+ ions into the pores, respectively. Tunable luminescence in MOFs is achieved by the two kinds of doping methods. In particular, the quantum yields of heterometal-organic frameworks are apparently enhanced by postencapsulation of lanthanide. [Ni(L)Eu](NO3)·5H2O·6DMA (IFMC-26-Eu) [Ni(L)Eu0.5Tb0.5](NO3)·5H2O·6DMA (IFMC-26-Eu0.5Tb0.5) [Ni(L)Tb](NO3)·5H2O·6DMA (IFMC-26-Tb) [Ni(L)La2(NO3)3(DMA)](NO3)·2H2O·2DMA (IFMC-27-La) [Ni0.5(H4L)0.5](N03)·4CH3CH2OH (the metalloligand) [Ni(L)La(H2O)(DMF)2](NO3)·3H2ODMF (IFMC-28-La) [Ni(L)Eu(H2O)(DMF)2](NO3)·3H2ODMF (IFMC-28-Eu) [Ni(L)Eu0.6Tb0.4(H2O)(DMF)2](NO3)·3H2O·DMF (IFMC-28-Eu0.6Tb0.4) [Ni(L)Eu0.5Tb0.5(H2O)(DMF)2](NO3)·3H2O·DMF (IFMC-28-Eu0.5Tb0.5) [Ni(L)Eu0.4Tb0.6(H2O)(DMF)2](NO3)·3H2O·DMF (IFMC-28-Eu0.4Tb0.6) [Ni(L)Tb(H2O)(DMF)2](NO3)·3H2O·DMF (IFMC-28-Tb)2. In this work, five novel 2D isostructural Cd(?)-lanthanide(?) heterometallic-organic frameworks have been successfully synthesized by taking advantage of different molar ratios of lanthanide(?) (Ln3+) and metalloligands under solvothermal conditions. Further luminescent measurements indicate that these compounds exhibit characteristic sharp emission bands of Eu3+ and Tb3+, and the intensities of red and green can be modulated correspondingly by tuning the ratios of Eu3+ and Tb3+. Particularly, IFMC-36-Eu shows a potential application in detection of small-molecule pollutant nitrobenzene by significant fluorescence quenching. Furthermore, IFMC-36-Eu displays preeminent anti-interference ability and could be used for sensing in the systems with complicated components. This is the first time that a d-f heterometallic-organic framework can be investigated as a chemical sensor for selective, sensitive, and recyclable detection of nitrobenzene. [CdCl(L)Eu(H2O)(DMA)](NO3)·3DMA (IFMC-36-Eu) [CdCl(L)Eu0.6Tb0.4(H2O)(DMA)](NO3)·3DMA (IFMC-36-Eu0.6Tb0.4) [CdCl(L)Eu0.5Tb0.5(H2O)(DMA)](NO3)·3DMA (IFMC-36-Eu0.5Tb0.5) [CdCl(L)Eu0.4Tb0.6(H2O)(DMA)](NO3)·3DMA (IFMC-36-Eu0.4Tb0.6) [CdCl(L)Tb(H2O)(DMA)](NO3)·3DMA (IFMC-36-Tb)3. A 2D and extremely stable MOF, NENU-503, was successfully constructed. It displays highly selective and recyclable properties in detection of nitroaromatic explosives as a fluorescent sensor. This is the first MOF that can distinguish between nitroaromatic molecules with different numbers of-NO2 groups. [Cd2Cl(H2O)(L)]·4.5DMA (NENU-503)4. In this work, a novel microporous anionic MOF, NENU-505, has been rationally synthesized under solvothermal conditions. Charge neutrality is achieved by [(CH3)2NH2]+ ions. It is noteworthy that NENU-505 displays high stability in air for more than two months. In particular, the adsorption ability of NENU-505 toward ionic dyes has been also investigated. According to the UV/vis spectroscopy analysis and the colour variance of NENU-505, we found that the cationic dyes could be efficiently adsorbed. Therefore, NENU-505 exhibits selective adsorption toward cationic dyes and can potentially serve as a column-chromatographic filler for the separation of dye molecules. Furthermore, NENU-505 performs as a rare example of a highly selective and sensitive sensor for Cr3+ ions. [Zn(ABTC)0.5(NO3)][(CH3)2NH2]·DMA·3H2O (NENU-505)...