Design,Synthesis Of Luminescent Metal-Organic Frameworks And Their Sensing Properties

Luminescent metal-organic frameworks（MOFs）,self-assembled from metal ions or clusters with organic ligands,can provide a fascinating platform for developing functional luminescent materials that can be applied in fluorescence sensing for their high porosity,remarkable structural tailorability and functionalizability.Recently,luminescent sensing with MOF materials has been considered as one of the most promising methods for chemical detection application because of their significant advantages,such as short response time,high sensibility,high selectivity,ease to operate.In order to further develop the new luminescent MOFs material for fluorescence sensing application,we elaborately selected electron richπ-conjugated aromatic carboxylate ligands to react with transition or rare earth metal ions under solvothermal condition,and successfully obtained a series of MOFs.The main work is the follows:1.We selected electron richπ-conjugated 1,4-naphthalenedicarboxylic acid（H₂L1）to react with Tb³⁺,Eu³⁺,Tb³⁺/Zn²⁺,Tb³⁺/Ca²⁺,Eu³⁺/Zn²⁺and Eu³⁺/Ca²⁺,and successfully obtained six MOFs,[Tb₂（L1）₃（DMA）]_n（1）,[Eu₂（L1）₃（DMA）]_n（2）,[Tb₆Zn（μ₃-OH）₈（L1）₆（H₂O）₆]_n（3）,[Tb₆Ca（μ₃-OH）₈（L1）₆（H₂O）₆]_n（4）,[Eu₆Zn（μ₃-OH）₈（L1）₆（H₂O）₆]_n（5）and[Eu₆Ca（μ₃-OH）₈（L1）₆（H₂O）₆]_n（6）.Complexs 1-2are isostructural,presenting 3D porous framework one-dimensional channels along the crystallographic b-axis.Complexs 3-6 are isostructural,which are constructed from heterometallic clusters and electron richπ-conjugated L1^2-.The luminescence properties of complexes 1 and 5 are investigated.Complex 5 exhibits highly sensitive,selective and reversible detection of ronidazole（RNZ）in water.2.We selected nanosized acylamide-functionalized dicarboxylate ligand4,4-（（naphthalene-1,4-dicarbonyl）bis（azanediyl））dibenzoic acid（H₂L2）to react with transition and rare earth metal ions,and successfully obtained eight MOFs,{[Zn_2.5（L2）₂（phen）（H₂O）₂Cl]}_n（7）,{[Zn₂（L2）₂（bpp）（H₂O）]·DMF·3H₂O}_n（8）,{[Zn（L2）（bpe）_0.5]·DMF}_n（9）,{[Cd₂（L2）₂（phen）₂]·DMA·3H₂O}_n（10）,{[Cd₂（L2）₂（bpea）]·DMF·2H₂O}_n（11）,[Cd（L2）（DMF）]_n（12）,{[Cd（L）（4,4’-bipy）]·DMA·5H₂O}_n（13）and{[Eu₂（L2）₂（OH）₂]·H₂O}_n（14）.Complexs 7and 10 show 1D zig-zag chains.Complexes 8,11 and 12 display 2D layers.Complexes 9,13 and 14 feature 3D frameworks.Interesting,complexes 12 and 13 are homochiral,both are obtained by a spontaneous symmetry-breaking crystallization from achiral precursors without any enantiopure auxiliary.The luminescence properties of complexes 7-14 are investigated.In addition,Complex 13 exhibits an interesting enantioselective sensing of D/L-penicillamine（Pen）in water.3.We selected hydrophobic alkyl-containing acylamide-functionalized dicarboxylate ligand 4,4-（（naphthalene-1,4-dicarbonyl）bis（azanediyl））bis（2-methyldibenzoic acid）（H₂L3）to react with transition and rare earth metal ions,and successfully obtained four MOFs,{[Cd₂（L3）₂]·DMF}_n（15）,{[Cd（L3）（bpp）]·DMF·2H₂O}_n（16）,{[Eu₂（L3）₃（H₂O）₂]·H₂O}_n（17）and{[Tb₂（L3）₃（H₂O）₂]·H₂O}_n（18）.Complexe 15 show 2D layer structure.Complex16 possesses a 3-fold 2D+2D→2D interwoven sheet structure.Complexs 17 and 18 are isostructural,displaying 3D network with 1D channels.Due to incorporating hydrophobic groups near coordination sites,these complexes shown good water stability.The luminescence properties of complexes 15-17 are also investigated.Complex 17 represents excellent fluorescent properties,which can be efficiently quenched by 2,4,6-trinitrophenol（TNP）in water.