| Homochiral metal-organic frameworks(HMOFs)are novel crystalline multifunctional materials.They not only have the advantages of metal-organic frameworks(MOFs),but also have the advantages of unique chiral environment,large porosity,rich structural types,and adjustable pore radius and chemical environment.Consequently,they have potential applications in chiral recognition and resolution,fluorescent probes,gas storage and separation and asymmetric catalysis.The key to the construction of HMOFs materials with novel structure and unique properties is the design and synthesis of novel enantiomatically pure chiral organic ligands.Therefore,natural chiral glutamic acid was used to modify tripyridine derivatives,and enantiomatically pure chiral tripyridine derivative ligands with large skeletons were designed and synthesized in this thesis.Based on these synthesized ligands,we constructed a series of HMOFs materials,and studied their structure and related properties.In this thesis,six two-dimensional isostructural homochiral metal-organic frameworks(HMOFs)with one-dimensional nanometer channels,namely[Eu(S-L1)(NO3)2]·n(solvent)(1),[Tb(S-L1)(NO3)2]·n(solvent)(2),[Pr(S-L1)(NO3)2]·n(solvent)(3),[Eu(R-L1)(NO3)2]·n(solvent)(4),[Tb(R-L1)(NO3)2]·n(solvent)(5)and[Pr(R-L1)(NO3)2]·n(solvent)(6),were solvothermally synthesized by self-assemblies of chiral enantiomers S-HL1[(S)-5-Oxo-1-(4-[2,2’;6’,2"]terpyridin-4’-yl-benzyl)-pyrrolidine-2-carboxylic acid]and R-HL1[(R)-5-Oxo-1-(4-[2,2’;6’,2"]terpyridin-4’-yl-benzyl)-pyrrolidine-2-carboxylic acid]with lanthanoid ions Eu(Ⅲ),Tb(Ⅲ)and Pr(Ⅲ),respectively.The use of an enantiomatically pure chiral ligand(S)-5-(((1-carboxy-2-phenylethyl)amino)methyl)isophthalic acid(H3L2)to assemble with Cu(Ⅱ)salt resulted in a novel three-dimensional porous HMOF,namely[Cu2(HL2)2(bpb)]·nH2O(7)[bpb=1,4-di(pyridin-4-yl)benzene]·The structures and related properties of these complexes were characterized by infrared spectra,single crystal X-ray diffraction analysis,powder X-ray diffraction analysis,circular dichroism(CD)spectra,fluorescence and thermal analysis.In this thesis,homochiral metal-organic framework materials 1,2,4,5 and 7,which were activated by desolvation,were used as solid-phase chiral adsorbents,and enantiomatically pure chiral phenylethylamine and phenylethanol were selected as adsorbed target molecules,and the enantioselective adsorption properties of these homochiral metal-organic framework materials for R-and S-phenylethanamine or Rand S-phenylethanol were systematically studied.The results show that materials 1 and 2 have larger adsorption capacity and better enantioselective adsorption performance for S-phenylethanamine and S-phenylethanol,while their enantiomer materials 4 and 5 have larger adsorption capacity and better enantioselective adsorption performance for for R-phenylethanamine and R-phenylethanol,and material 7 has large adsorption capacity and good enantioselective adsorption performance for R-phenylethanol.The enantioselective adsorption ratio ra of materials 1,2,4,5 and 7 varies with the change of substrate concentration.When the initial concentration of substrates is 30 mM,these materials have larger adsorption capacity and ahigh enantioselective adsorption ratio ra.Although materials 2 and 5 are isomorphic with materials 1 and 4,materials 2 and 5 with Tb(Ⅲ)as metal nodes and materials 1 and 4 with Eu(III)as metal nodes show slightly different enantioselective adsorption performance in the adsorption of enantiomers of chiral phenylethylamine and phenylethanol.Further adsorption kinetics studies show that when the initial concentration of substrates is 50 mm,the adsorption of R/S-phenylethanamine or R/Sphenylethanol by materials 1,2,4 and 5 can basically reach saturation within 32 h,and the adsorption of R/S-phenylethanol by material 7 can basically reach saturation within 10 h.The maximum adsorption rates of material 1 for R-phenylethanamine,S-phenylethanamine,R-phenylethanol and S-phenylethanol are about 2.2%,3.0%,2.5%and 3.3%,respectively.The maximum adsorption rates of material 4 for R-phenylethanamine,S-phenylethanamine,R-phenylethanol and S-phenylethanol are about 3.3%,2.5%,4.3%and 3.7%,respectively.The maximum adsorption rates of material 2 for R-phenylethanamine,S-phenylethanamine,R-phenylethanol and S-phenylethanol are about 2.3%,2.9%,2.4%and 3.2%,respectively.The maximum adsorption rates of material 5 for R-phenylethanamine,S-phenylethanamine,R-phenylethanol and S-phenylethanol are about 3.1%,2.7%,4.0%and 3.2%,respectively.The maximum adsorption rates of material 7 for R-phenylethanol and S-phenylethanol are about 9.0%and 6.2%,respectively.The above results indicate that the five HMOFs have certain enantiomeric resolution ability for the racemic mixture of 1-phenylethylamine or 1-phenylethanol.Based on the analysis of high performance liquid chromatography with chiral column,the resolution properties of materials 1,2 and 7 for the enantioseparation of racemic 1-phenylethanol were further studied.The material 1 has better enantioseparation for the racemic mixture 1-phenylethanol,and the enantiomeric excess(ee)value is about 15.6%,while the enantiomeric excess value of the material 2 for enantioseparation of the racemic mixture 1-phenylethanol is about 15.4%.Material 7 has high adsorption and enantioseparation performance for 1-phenylethanol enantiomer mixture,and the enantiomeric excess value is about 20.2%. |
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