A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er（btc）（ED）075（H2O）0.25 （2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine）, Er（btc）（PP）0.5...A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er（btc）（ED）075（H2O）0.25 （2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine）, Er（btc）（PP）0.55（H20）0.45 （3, PP = piperazine）, and Er（btc）（DABCO）0.15（H2O）0.85 （4, DABCO = 1,4- diazabicyclo[2.2.2]octane）, by grafting three different diamines onto the coordinatively unsaturated Er（III） ions into the channels of the desolvated lanthanide metal-organic framework （Er（otc））. The resulting metal-organic frameworks were characterized by elemental analysis, thermogravimetric analysis, powder X-ray diffraction, and N2 adsorption. Based on its higher loading ratio of the diamine, as well as its greater stability and porosity, catalyst 2 exhibited higher catalytic activity and reusability than catalysts 3 and 4- for the Knoevenagel condensation reaction. The catalytic mechanism of 2 has also been investigated using size-selective catalysis tests.展开更多
A chiral lanthanide metal-organic framework based on enantiopure camphoric acid （D-H2cam）, [Nd3（D-cam）8（H2O）4Cl]n （1）, has been synthesized and characterized by single-crystal X-ray structural analysis, elemen...A chiral lanthanide metal-organic framework based on enantiopure camphoric acid （D-H2cam）, [Nd3（D-cam）8（H2O）4Cl]n （1）, has been synthesized and characterized by single-crystal X-ray structural analysis, elemental analysis, IR, thermal gravimetric, and X-ray powder diffraction. Crystal data for the title compound are as follows： orthorhombic system, space group P212121 with a = 13.8287（7）, b = 14.0715（7）, c = 25.7403（12） A^°, V = 5008.8（4） A^°3, Mr = 1333.08, Z = 4, F（000） = 2644, Dc = 1.768 g/cm^3, μ（MoKα） = 3.189 mm^-1, the final R = 0.0351 and wR = 0.0814 （I 〉 2σ（I））. Compound 1 displays an 8-connected bcu topology 3D framework and hydrogen-bonding interactions stabilize the solid-state structure. The vibrational circular dichroism （VCD） spectrum and second-order nonlinear optical effect of compound 1 have been studied in the solid state.展开更多
A 3-D supramolecular framework, [Er（pybz）2（Hnds）（H2O）2]·H2O （1, Hpybz = 4- pyridin-4-yl-benzoic acid, H2nds = naphthalene-1,5-disulfonic acid）, based on lanthanide ions and mixed ligands has been hydrothe...A 3-D supramolecular framework, [Er（pybz）2（Hnds）（H2O）2]·H2O （1, Hpybz = 4- pyridin-4-yl-benzoic acid, H2nds = naphthalene-1,5-disulfonic acid）, based on lanthanide ions and mixed ligands has been hydrothermally synthesized. The structure was determined by single-crystal X-ray diffraction and further characterized by IR, elemental analysis and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic system, space group P21/n with a = 9.849（2）, b = 22.526（5）, c = 17.167（4） A, β =105.461（4）° and V = 3670.9（2） A^3. In 1, two seven-coordinated Er^3＋ ions are bridged by two pybz^- ligands to form a dimeric [Er2（COO）2] unit, which is further orderly linked by carboxyl of pybz^-ligand to obtain a 1-D chain running along the a axis. Interestingly, significant H-bonding and π-π stacking interactions link the neighboring parallel chains leading to a 3-D supramolecular network structure which displays 1-D rhombus open channels （17.2A× 22.5A）.展开更多
The reaction of Pr（Ⅲ） salt with 1,2,4,5-benzenetetracarboxylic acid（H4betc） and piperazine（pip） yielded a lanthanide metal-organic framework {[Pr（betc）（H2O）2]（H2pip）0.5}n（1）under hydrothermal conditions...The reaction of Pr（Ⅲ） salt with 1,2,4,5-benzenetetracarboxylic acid（H4betc） and piperazine（pip） yielded a lanthanide metal-organic framework {[Pr（betc）（H2O）2]（H2pip）0.5}n（1）under hydrothermal conditions. Compound 1 was characterized by single-crystal X-ray structural analysis, elemental analysis, IR, X-ray powder diffraction, and thermal gravimetric. Compound 1crystallizes in monoclinic, space group P21/n with a = 11.023（5）, b = 11.109（5）, c = 11.456（5） A, β = 110.065（5）°, V = 1317.7（9） A3, Mr = 471.14, Z = 4, F（000） = 920, Dc = 2.375 g/cm^3, μ（Mo Kα） = 3.761 mm-1, the final R = 0.0286 and w R = 0.0821（I 〉 2σ（I））. Compound 1 exhibits a 2D network with（4, 4） topology, and a 3D supramolecular framework formed by hydrogen-bonding interactions. The proton conductivity of compound 1 has been investigated at ~97% relative humidity and different temperature.展开更多
Two coordination polymers of lanthanide complexes [（Dy）2（3,5-PDA）3（H2O）2]n 1 and [（Pr）2（3,5-PDA）3（H2O）3]n 2 （3,5-PDA = pyridine-3,5-dicarboxylate） have been synthesized under hydrothermal conditions. The...Two coordination polymers of lanthanide complexes [（Dy）2（3,5-PDA）3（H2O）2]n 1 and [（Pr）2（3,5-PDA）3（H2O）3]n 2 （3,5-PDA = pyridine-3,5-dicarboxylate） have been synthesized under hydrothermal conditions. The prepared compounds were characterized by elemental analysis, IR and TG analyses and single-crystal X-ray structure determination. Complex 1 crystallizes in monoclinic, space group C2/c with a = 14.104（2）, b = 11.1129（16）, c = 15.086（2） , β = 92.138（2）o, V = 2362.8（6） 3, Z = 4, C21H13Dy2N3O14, Mr = 856.34, Dc = 2.407 g·cm-3, F（000） = 1616, μ（MoKα） = 6.359 mm-1, the final R = 0.0422 and wR = 0.1016 for 2000 observed reflections with I 2σ（I）. Complex 2 crystallizes in triclinic, space group P with a = 8.9441（13）, b = 9.3959（14）, c = 14.625（2） , α = 98.065（2）, β = 95.481（2）, γ = 104.9130（10）o, V = 1164.7（3） 3, Z = 2, C21H15Pr2N3O15, Mr = 831.18, Dc = 2.370 g·cm-3, F（000） = 800, μ（MoKα） = 4.224 mm-1, the final R = 0.0355 and wR = 0.0731 for 4092 observed reflections with I 2σ（I）. These polymers are constructed from the 3,5-PDA ligand but they exhibit different kinds of metal-organic framework structures. Complexes 1 and 2 are constructed from M-C-O zigzag corner-linked chains （M = Dy and Pr）. In 1, the chains are composed of 8-coordinated DyⅢ centers, while the chains are made up of 8- and 9-coordinated PrIII centers in complex 2. These chains are cross-linked to each other by the pyridine rings of 3,5-PDA ligands, generating three-dimensional architectures. The magnetic behavior of compound 1 has been investigated, showing it exhibits antiferromagnetic interactions among the DyⅢ ions.展开更多
A series of undoped and lanthanide doped MIL-53(Fe)/Ln-Fe_(3)O_(4)(Ln=La,Nd,or Gd) metal-organic frameworks(MOFs) were prepared by the solvothermal method.All prepared samples were characterized by X-ray diffraction(X...A series of undoped and lanthanide doped MIL-53(Fe)/Ln-Fe_(3)O_(4)(Ln=La,Nd,or Gd) metal-organic frameworks(MOFs) were prepared by the solvothermal method.All prepared samples were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),Brunauer-Emmett-Teller(BET) measurements,scanning electron microscopy(SEM),and thermal analysis.XRD and FT-IR results ascertain the successful MOF formation for all prepared samples.MIL-53(Fe)/La-Fe_(3)O_(4) has the smallest particle size of 8.6 nm,the largest BET surface area of 54.2 m^(2)/g,and the highest porosity.Undoped and different lanthanide doped MIL-53(Fe) we re employed as sorbents for the removal of methylene blue(MB)dye from aqueous solutions to examine the doping benefit and the effect of the dopant size on the sorption performance.Doping causes MOFs to act as pH-independent sorbents,which make it applicable at any condition.Adsorption follows pseudo-second-order kinetic model,and doped sorbents attain equilibrium faster.Langmuir isotherms are followed,except for MIL-53(Fe)/La-Fe_(3)O_(4).The adsorption capacity increases with increasing the dopant ion size,100.5 mg/g for La-doped MOF,which is about four times higher than that of undoped MOF.The adsorption mechanism involves chemical interactions between Lewis acid in magnetite MIL-53(Fe) series and Lewis base in MB.展开更多
In this study,an alkynyl-modified aromatic dicarboxylic acid bifunctional ligand was selected to construct lanthanide compound{[Eu_(4)(ebdc)_(6)(4,4-bpy)_(0.5)(H_(2)O)_(4.5)]·(C_(2)H_(5)OH)_(1.25)(H_(2)O)}_(n)(Eu...In this study,an alkynyl-modified aromatic dicarboxylic acid bifunctional ligand was selected to construct lanthanide compound{[Eu_(4)(ebdc)_(6)(4,4-bpy)_(0.5)(H_(2)O)_(4.5)]·(C_(2)H_(5)OH)_(1.25)(H_(2)O)}_(n)(Eu-MOF,H_(2)ebdc=5-ethynyl-isophthalic acid,4,4-bpy=4,4-bipyridine,MOF=metal-organic framework),of which the uncoordinated alkynyl group would be used to anchor silver nanoclusters(Ag NCs).The Eu-MOF exhibits double emission peaks,located at 492 and 611 nm,respectively,in which the high-energy blue emission is associated with alkynyl-modified ligand while the low-energy red emission belongs to characteristic emission of Eu3+,indicating that ligands can effectively sensitize Eu3+luminescence.The intensity ratio of the dual emission fluorescence peaks of Eu-MOF displays a good linear relationship with temperature,which realizes the detection function in the low temperature region of 75–275 K,the thermal sensitivity reaches 1.5398%·K^(−1).After anchoring the Ag NCs,the high-energy blue emission is significantly quenched,indicating that the Ag NCs are indeed confined into the framework and interact with the alkynyl group,and thus change the overall electronic distribution.This is the first case of anchoring Ag NCs by a luminescent Eu-MOF and studying nanocluster loading by using spectroscopic properties.In addition,the Ag NCs@Eu-MOF also shows a good catalytic activity for cycloaddition reaction from CO_(2)and epoxides.This study not only provides ideas for exploring the changes in optical properties of luminescent MOFs and Ag NCs caused by confinement effect,but also expands their potential applications in various fields.展开更多
Various ions and antibiotics,widely used in industry and clinical medicine,respectively,are massively discharged to atmosphere and water,resulting in severe pollutions on environment and potential threats to human hea...Various ions and antibiotics,widely used in industry and clinical medicine,respectively,are massively discharged to atmosphere and water,resulting in severe pollutions on environment and potential threats to human health.Besides,amino acids,the primary substances for the establishment of proteins,cells and tissues,are crucial to human health.Therefore,seeking effective and practicable materials to detect aforesaid analytes is vitally meaningful.Metal-organic frameworks centered with lanthanide ions(Ln-MOFs),also known as lanthanide coordination polymers,are considered as a charming category of multi-functional hybrid crystalline materials with fascinating structures and incomparable luminescent characteristics.Benefited from their unique merits,Ln-MOFs have been largely developed as excellent luminescent sensors for fast and efficient sensing various analytes.In this review,we aim to introduce some of the recent researches between 2018 to 2022 on Ln-MOFs applied as chemical sensors for ions,antibiotics and amino acids based on luminescent quenching and enhancing effects,and provide an update and summary for the latest progresses in this field.展开更多
A new lanthanide metal-organic framework (MOF)[Eu(BTB)(phen)(DMF)]·DMF (1,DMF=N,N-dimethylformamide) was synthesized using H_(3)BTB (1,3,5-tri(4-carboxyphenyl)benzene) and phen(1,10-phenanthroline) under solvothe...A new lanthanide metal-organic framework (MOF)[Eu(BTB)(phen)(DMF)]·DMF (1,DMF=N,N-dimethylformamide) was synthesized using H_(3)BTB (1,3,5-tri(4-carboxyphenyl)benzene) and phen(1,10-phenanthroline) under solvothermal conditions.The structure of the prepared MOF was characterized by single-crystal X-ray diffraction analyses,elemental analysis,fluorescence spectrum,FT-IR spectroscopy,powder X-ray diffraction and thermogravimetric analyses.The structure of 1 can be viewed as a 3-D supramolecular network,which is formed by the stacking of 2D layers throughπ-πinteraction.The luminescence explorations revealed that 1 possesses favorable selectivity and sensitivity for testing Fe^(3+).Additionally,color tuning was achieved by varying Eu^(3+):Tb^(3+)ratios in the reaction mixtures.展开更多
Two novel 3D metal-organic frameworks(MOFs)with cds network,{[Me NH_3]_7[Ln_8(Pg C_2)_2(H_2O)_y(HCOO)_7]}_n·x(Solvent)(FJI-Y4,FJI=Fujian Institute,Ln=Gd,y=12;FJI-Y5,Ln=Dy,y=11;Pg C_2=C-ethylpyrogallol[4]arene),ba...Two novel 3D metal-organic frameworks(MOFs)with cds network,{[Me NH_3]_7[Ln_8(Pg C_2)_2(H_2O)_y(HCOO)_7]}_n·x(Solvent)(FJI-Y4,FJI=Fujian Institute,Ln=Gd,y=12;FJI-Y5,Ln=Dy,y=11;Pg C_2=C-ethylpyrogallol[4]arene),based on unprecedented dimeric pyrogallol[4]arene-based Ln_8metal-organic nanocapsule(MONC)supramolecular building blocks and formate linkers,have been prepared under solvothermal conditions.To our best of knowledge,they present not only the first two examples of 3D hierarchical structures constructed from MONCs in metal-pyrogallol[4]arene system,but also the first two examples of MOFs based on lanthanide MONCs.Remarkably,the inner cavity volume of the Ln_8capsule in FJI-Y4 and FJI-Y5 is approximately151?~3,which is larger than those found in previous transition metal-seamed dimeric Pg C_n-based MONCs.Magnetic investigation on FJI-Y4 suggests a significant magnetocaloric effect(23.97 J kg^(-1)K^(-1),ΔH=7 T,2.5 K),while FJI-Y5 exhibits slow relaxation of the magnetization.展开更多
Proton-conductive metal-organic frameworks(MOFs)have attracted great attention for their promising application in membrane fuel cells.To explore proton-conductive MOFs with high performance,here we present four lantha...Proton-conductive metal-organic frameworks(MOFs)have attracted great attention for their promising application in membrane fuel cells.To explore proton-conductive MOFs with high performance,here we present four lanthanide-hypophosphite frameworks with distinct amine guests.These complexes possess a general formula[AH][Gd_(2)(H_(2)PO_(2))_(7)(AH=protonated amines)].Due to the rich hydrogen bond networks,complex 1 with guanidinium as guest shows high proton conductivity of 1.75×10^(-2) S·cm^(-1) at a relative humidity of 97%(368 K).We also studied the magnetic properties of complex 1 and reveal that the hypophosphite ligand transfers weak antiferromagnetic interactions between Gd^(3+)ions.展开更多
Three isostructural three-dimensional （3D） lanthanide-based metal-organic frameworks [Ln2L（H2L）（NMP）2]＇H20 （Ln=Sm（l）, Eu （2）, Gd （3）; H4L= 1,1 ＇：4＇, 1 ＂-terphenyl-2＇,4,4＂,5＇-tetracarboxylic acid; ...Three isostructural three-dimensional （3D） lanthanide-based metal-organic frameworks [Ln2L（H2L）（NMP）2]＇H20 （Ln=Sm（l）, Eu （2）, Gd （3）; H4L= 1,1 ＇：4＇, 1 ＂-terphenyl-2＇,4,4＂,5＇-tetracarboxylic acid; NMP=N-methyl-2-pyrrolidone） have been synthesized and structurally characterized. In 1-3, two Ln3＋ ions are doubly-bridged by two oxygen atoms of two carboxylate groups to form the dinuclear Lnz（Oco ）a unit. Each Ln2（Ocoo ）2 unit links with four H2L2 ligands and four L4- ligands to lead to the 3D framework, which can be rationalized as a new trinodal 4,4,8-connected （44.62）（45.6）（412.616） topological network by considering the dinuclear Ln2（Ocoo ）2 units as 8-connected nodes and L4-/H2L2- ligands as planar 4-connected nodes, respectively. 1 and 3 exhibit blue emission originated from the ligand with the emission maximum at 384 nm, while 2 shows intense characteristic red emission of Eu3＋ ions and weak ligand-centered emission. Moreover, 2 has fluorescent quenching response towards the aromatic nitro compounds, especially for the 3,4-dinitrotoluene （3,4-DNT） with the linear Stern-Volmer relationship in the concentration range of 0-1 mM and the quenching constant （Ksv） of 2.084-103 M 1.展开更多
Two series of lanthanide-containing metal-organic frameworks(Ln-MOFs)of the general formula{[Ln(HIDA)_(2)H_(2)O]ClO_(4)·H_(2)O}_n(Ln=La(1),Nd(2),Eu(3),Gd(4),Tb(5),Eu:Tb(6);H_(2)IDA=iminodiacetic acid)and[Ln(TT)(H...Two series of lanthanide-containing metal-organic frameworks(Ln-MOFs)of the general formula{[Ln(HIDA)_(2)H_(2)O]ClO_(4)·H_(2)O}_n(Ln=La(1),Nd(2),Eu(3),Gd(4),Tb(5),Eu:Tb(6);H_(2)IDA=iminodiacetic acid)and[Ln(TT)(HTT)(H_(2)O)_3]_n(Ln=Eu(7),Gd(8),Tb(9),Dy(10),and Eu:Tb(11);H_(2)TT=tartaric acid)were synthesized by reacting Ln(ClO_(4))_3 with iminodiacetic acid and L-tartaric acid,respectively.All compounds were structurally characterized by single-crystal X-ray diffraction.Elemental analyses are co nsistent with the corre sponding crystallographically generated formulas.Mo reover,the luminescence properties of both the single and mixed-lanthanide complexes were studied.Near infrared,red,and green emissions that are characteristic of Nd(Ⅲ),Eu(Ⅲ),and Tb(Ⅲ)are observed for 2,3/7,and 5/9,respectively.For the two mixed-lanthanide complex systems 6 and 11,depending on the relative amount of Eu(Ⅲ)and Tb(Ⅲ),the color of emission can be fine-tuned.It is found that a small amount of Eu(Ⅲ)is adequate for the observation of the most intense transition of Eu(Ⅲ).This is believed to be a result of energy transfer from Tb(Ⅲ)to Eu(Ⅲ)within the same complex-a conclusion supported by the significantly shortened lifetime of Tb(Ⅲ)and the accompanying enhanced lifetime of Eu(Ⅲ)in the mixedlanthanide complex with respect to the corresponding values for the pure Tb(Ⅲ)and Eu(Ⅲ)complexes with the same ligand.展开更多
基金supported by the National Natural Science Foundation of China(21372087)~~
文摘A post-synthetic modification strategy has been used to prepare three solid base catalysts, including Er（btc）（ED）075（H2O）0.25 （2, btc = 1,3,5-benzenetricarboxylates, ED = 1,2-ethanediamine）, Er（btc）（PP）0.55（H20）0.45 （3, PP = piperazine）, and Er（btc）（DABCO）0.15（H2O）0.85 （4, DABCO = 1,4- diazabicyclo[2.2.2]octane）, by grafting three different diamines onto the coordinatively unsaturated Er（III） ions into the channels of the desolvated lanthanide metal-organic framework （Er（otc））. The resulting metal-organic frameworks were characterized by elemental analysis, thermogravimetric analysis, powder X-ray diffraction, and N2 adsorption. Based on its higher loading ratio of the diamine, as well as its greater stability and porosity, catalyst 2 exhibited higher catalytic activity and reusability than catalysts 3 and 4- for the Knoevenagel condensation reaction. The catalytic mechanism of 2 has also been investigated using size-selective catalysis tests.
基金supported by National Natural Science Foundation of China(21401147)Basic Research Program of Natural Science from Shaanxi Provincial Government(2015JQ2032)+2 种基金Scientific Research Program from Education Department of Shaanxi Provincial Government(2013JK0654)Opening Foundation from State Key Laboratory of Coordination Chemistry in Nanjing University(201219)the Program for Distinguished Young Scholars of Xi’an Polytechnic University(201403)
文摘A chiral lanthanide metal-organic framework based on enantiopure camphoric acid （D-H2cam）, [Nd3（D-cam）8（H2O）4Cl]n （1）, has been synthesized and characterized by single-crystal X-ray structural analysis, elemental analysis, IR, thermal gravimetric, and X-ray powder diffraction. Crystal data for the title compound are as follows： orthorhombic system, space group P212121 with a = 13.8287（7）, b = 14.0715（7）, c = 25.7403（12） A^°, V = 5008.8（4） A^°3, Mr = 1333.08, Z = 4, F（000） = 2644, Dc = 1.768 g/cm^3, μ（MoKα） = 3.189 mm^-1, the final R = 0.0351 and wR = 0.0814 （I 〉 2σ（I））. Compound 1 displays an 8-connected bcu topology 3D framework and hydrogen-bonding interactions stabilize the solid-state structure. The vibrational circular dichroism （VCD） spectrum and second-order nonlinear optical effect of compound 1 have been studied in the solid state.
基金supported by the National Natural Science Fund for Distinguished Young Scholars of China (No. 20725101)the 973 Program (No. 2006CB932904)+2 种基金the NSF of Fujian Province (Nos. E0510030 and 2008F3120)the Knowledge Innovation Program of CAS (No. KJCX2.YW.H01)NNSFC (No. 20521101)
文摘A 3-D supramolecular framework, [Er（pybz）2（Hnds）（H2O）2]·H2O （1, Hpybz = 4- pyridin-4-yl-benzoic acid, H2nds = naphthalene-1,5-disulfonic acid）, based on lanthanide ions and mixed ligands has been hydrothermally synthesized. The structure was determined by single-crystal X-ray diffraction and further characterized by IR, elemental analysis and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic system, space group P21/n with a = 9.849（2）, b = 22.526（5）, c = 17.167（4） A, β =105.461（4）° and V = 3670.9（2） A^3. In 1, two seven-coordinated Er^3＋ ions are bridged by two pybz^- ligands to form a dimeric [Er2（COO）2] unit, which is further orderly linked by carboxyl of pybz^-ligand to obtain a 1-D chain running along the a axis. Interestingly, significant H-bonding and π-π stacking interactions link the neighboring parallel chains leading to a 3-D supramolecular network structure which displays 1-D rhombus open channels （17.2A× 22.5A）.
基金supported by National Natural Science Foundation of China(21401147)Basic Research Program of Natural Science from Shaanxi Provincial Government(2015JQ2032)+2 种基金Scientific Research Program from Education Department of Shaanxi Provincial Government(2013JK0654)Opening Foundation from State Key Laboratory of Coordination Chemistry in Nanjing University(201219)the Program for Distinguished Young Scholars of Xi’an Polytechnic University(201403)
文摘The reaction of Pr（Ⅲ） salt with 1,2,4,5-benzenetetracarboxylic acid（H4betc） and piperazine（pip） yielded a lanthanide metal-organic framework {[Pr（betc）（H2O）2]（H2pip）0.5}n（1）under hydrothermal conditions. Compound 1 was characterized by single-crystal X-ray structural analysis, elemental analysis, IR, X-ray powder diffraction, and thermal gravimetric. Compound 1crystallizes in monoclinic, space group P21/n with a = 11.023（5）, b = 11.109（5）, c = 11.456（5） A, β = 110.065（5）°, V = 1317.7（9） A3, Mr = 471.14, Z = 4, F（000） = 920, Dc = 2.375 g/cm^3, μ（Mo Kα） = 3.761 mm-1, the final R = 0.0286 and w R = 0.0821（I 〉 2σ（I））. Compound 1 exhibits a 2D network with（4, 4） topology, and a 3D supramolecular framework formed by hydrogen-bonding interactions. The proton conductivity of compound 1 has been investigated at ~97% relative humidity and different temperature.
基金Supported by the NNSFC (No. 20761005)the Key Project of Chinese Ministry of Education (No. 205147)the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20060673015)
文摘Two coordination polymers of lanthanide complexes [（Dy）2（3,5-PDA）3（H2O）2]n 1 and [（Pr）2（3,5-PDA）3（H2O）3]n 2 （3,5-PDA = pyridine-3,5-dicarboxylate） have been synthesized under hydrothermal conditions. The prepared compounds were characterized by elemental analysis, IR and TG analyses and single-crystal X-ray structure determination. Complex 1 crystallizes in monoclinic, space group C2/c with a = 14.104（2）, b = 11.1129（16）, c = 15.086（2） , β = 92.138（2）o, V = 2362.8（6） 3, Z = 4, C21H13Dy2N3O14, Mr = 856.34, Dc = 2.407 g·cm-3, F（000） = 1616, μ（MoKα） = 6.359 mm-1, the final R = 0.0422 and wR = 0.1016 for 2000 observed reflections with I 2σ（I）. Complex 2 crystallizes in triclinic, space group P with a = 8.9441（13）, b = 9.3959（14）, c = 14.625（2） , α = 98.065（2）, β = 95.481（2）, γ = 104.9130（10）o, V = 1164.7（3） 3, Z = 2, C21H15Pr2N3O15, Mr = 831.18, Dc = 2.370 g·cm-3, F（000） = 800, μ（MoKα） = 4.224 mm-1, the final R = 0.0355 and wR = 0.0731 for 4092 observed reflections with I 2σ（I）. These polymers are constructed from the 3,5-PDA ligand but they exhibit different kinds of metal-organic framework structures. Complexes 1 and 2 are constructed from M-C-O zigzag corner-linked chains （M = Dy and Pr）. In 1, the chains are composed of 8-coordinated DyⅢ centers, while the chains are made up of 8- and 9-coordinated PrIII centers in complex 2. These chains are cross-linked to each other by the pyridine rings of 3,5-PDA ligands, generating three-dimensional architectures. The magnetic behavior of compound 1 has been investigated, showing it exhibits antiferromagnetic interactions among the DyⅢ ions.
文摘A series of undoped and lanthanide doped MIL-53(Fe)/Ln-Fe_(3)O_(4)(Ln=La,Nd,or Gd) metal-organic frameworks(MOFs) were prepared by the solvothermal method.All prepared samples were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR),Brunauer-Emmett-Teller(BET) measurements,scanning electron microscopy(SEM),and thermal analysis.XRD and FT-IR results ascertain the successful MOF formation for all prepared samples.MIL-53(Fe)/La-Fe_(3)O_(4) has the smallest particle size of 8.6 nm,the largest BET surface area of 54.2 m^(2)/g,and the highest porosity.Undoped and different lanthanide doped MIL-53(Fe) we re employed as sorbents for the removal of methylene blue(MB)dye from aqueous solutions to examine the doping benefit and the effect of the dopant size on the sorption performance.Doping causes MOFs to act as pH-independent sorbents,which make it applicable at any condition.Adsorption follows pseudo-second-order kinetic model,and doped sorbents attain equilibrium faster.Langmuir isotherms are followed,except for MIL-53(Fe)/La-Fe_(3)O_(4).The adsorption capacity increases with increasing the dopant ion size,100.5 mg/g for La-doped MOF,which is about four times higher than that of undoped MOF.The adsorption mechanism involves chemical interactions between Lewis acid in magnetite MIL-53(Fe) series and Lewis base in MB.
基金the National Natural Science Foundation of China(Nos.21975065,U21A20277,21825106,and 22201065).
文摘In this study,an alkynyl-modified aromatic dicarboxylic acid bifunctional ligand was selected to construct lanthanide compound{[Eu_(4)(ebdc)_(6)(4,4-bpy)_(0.5)(H_(2)O)_(4.5)]·(C_(2)H_(5)OH)_(1.25)(H_(2)O)}_(n)(Eu-MOF,H_(2)ebdc=5-ethynyl-isophthalic acid,4,4-bpy=4,4-bipyridine,MOF=metal-organic framework),of which the uncoordinated alkynyl group would be used to anchor silver nanoclusters(Ag NCs).The Eu-MOF exhibits double emission peaks,located at 492 and 611 nm,respectively,in which the high-energy blue emission is associated with alkynyl-modified ligand while the low-energy red emission belongs to characteristic emission of Eu3+,indicating that ligands can effectively sensitize Eu3+luminescence.The intensity ratio of the dual emission fluorescence peaks of Eu-MOF displays a good linear relationship with temperature,which realizes the detection function in the low temperature region of 75–275 K,the thermal sensitivity reaches 1.5398%·K^(−1).After anchoring the Ag NCs,the high-energy blue emission is significantly quenched,indicating that the Ag NCs are indeed confined into the framework and interact with the alkynyl group,and thus change the overall electronic distribution.This is the first case of anchoring Ag NCs by a luminescent Eu-MOF and studying nanocluster loading by using spectroscopic properties.In addition,the Ag NCs@Eu-MOF also shows a good catalytic activity for cycloaddition reaction from CO_(2)and epoxides.This study not only provides ideas for exploring the changes in optical properties of luminescent MOFs and Ag NCs caused by confinement effect,but also expands their potential applications in various fields.
基金financially supported by the National Natural Science Foundation of China(21801107)the Natural Science Foundation of Shandong Province(ZR2018BB005)the Youth Innovation Team of Shandong Colleges and Universities(2019KJC027)。
文摘Various ions and antibiotics,widely used in industry and clinical medicine,respectively,are massively discharged to atmosphere and water,resulting in severe pollutions on environment and potential threats to human health.Besides,amino acids,the primary substances for the establishment of proteins,cells and tissues,are crucial to human health.Therefore,seeking effective and practicable materials to detect aforesaid analytes is vitally meaningful.Metal-organic frameworks centered with lanthanide ions(Ln-MOFs),also known as lanthanide coordination polymers,are considered as a charming category of multi-functional hybrid crystalline materials with fascinating structures and incomparable luminescent characteristics.Benefited from their unique merits,Ln-MOFs have been largely developed as excellent luminescent sensors for fast and efficient sensing various analytes.In this review,we aim to introduce some of the recent researches between 2018 to 2022 on Ln-MOFs applied as chemical sensors for ions,antibiotics and amino acids based on luminescent quenching and enhancing effects,and provide an update and summary for the latest progresses in this field.
基金supported by the High-level Teachers in Beijing Municipal Universities in the Period of 13th Five-year Plan (CIT&TCD201904044)URT program of Beijing Institute of Petrochemical Technology (2020J00009)。
文摘A new lanthanide metal-organic framework (MOF)[Eu(BTB)(phen)(DMF)]·DMF (1,DMF=N,N-dimethylformamide) was synthesized using H_(3)BTB (1,3,5-tri(4-carboxyphenyl)benzene) and phen(1,10-phenanthroline) under solvothermal conditions.The structure of the prepared MOF was characterized by single-crystal X-ray diffraction analyses,elemental analysis,fluorescence spectrum,FT-IR spectroscopy,powder X-ray diffraction and thermogravimetric analyses.The structure of 1 can be viewed as a 3-D supramolecular network,which is formed by the stacking of 2D layers throughπ-πinteraction.The luminescence explorations revealed that 1 possesses favorable selectivity and sensitivity for testing Fe^(3+).Additionally,color tuning was achieved by varying Eu^(3+):Tb^(3+)ratios in the reaction mixtures.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB20000000)the National Natural Science Foundation of China (21390392, 51603206)the Nature Science Foundation of Fujian Province (2016J05056)
文摘Two novel 3D metal-organic frameworks(MOFs)with cds network,{[Me NH_3]_7[Ln_8(Pg C_2)_2(H_2O)_y(HCOO)_7]}_n·x(Solvent)(FJI-Y4,FJI=Fujian Institute,Ln=Gd,y=12;FJI-Y5,Ln=Dy,y=11;Pg C_2=C-ethylpyrogallol[4]arene),based on unprecedented dimeric pyrogallol[4]arene-based Ln_8metal-organic nanocapsule(MONC)supramolecular building blocks and formate linkers,have been prepared under solvothermal conditions.To our best of knowledge,they present not only the first two examples of 3D hierarchical structures constructed from MONCs in metal-pyrogallol[4]arene system,but also the first two examples of MOFs based on lanthanide MONCs.Remarkably,the inner cavity volume of the Ln_8capsule in FJI-Y4 and FJI-Y5 is approximately151?~3,which is larger than those found in previous transition metal-seamed dimeric Pg C_n-based MONCs.Magnetic investigation on FJI-Y4 suggests a significant magnetocaloric effect(23.97 J kg^(-1)K^(-1),ΔH=7 T,2.5 K),while FJI-Y5 exhibits slow relaxation of the magnetization.
基金This work was supported by the NFSC(Nos.22035003,91856124,21801137,21905142)the Program of Introducing Talents of Discipline to Universities(No.B18030).
文摘Proton-conductive metal-organic frameworks(MOFs)have attracted great attention for their promising application in membrane fuel cells.To explore proton-conductive MOFs with high performance,here we present four lanthanide-hypophosphite frameworks with distinct amine guests.These complexes possess a general formula[AH][Gd_(2)(H_(2)PO_(2))_(7)(AH=protonated amines)].Due to the rich hydrogen bond networks,complex 1 with guanidinium as guest shows high proton conductivity of 1.75×10^(-2) S·cm^(-1) at a relative humidity of 97%(368 K).We also studied the magnetic properties of complex 1 and reveal that the hypophosphite ligand transfers weak antiferromagnetic interactions between Gd^(3+)ions.
基金supported by the National Natural Science Foundation of China(61136003,61575096,51173081)the Ministry of Education of China(IRT1148),Natural Science Foundation of Jiangsu Province(BM2012010,BK20151512)+2 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions(YX03001)Specialized Research Fund for the Doctoral Program of Higher Education(20113223110005)the National Basic Research Program of China(2012CB933301)
文摘Three isostructural three-dimensional （3D） lanthanide-based metal-organic frameworks [Ln2L（H2L）（NMP）2]＇H20 （Ln=Sm（l）, Eu （2）, Gd （3）; H4L= 1,1 ＇：4＇, 1 ＂-terphenyl-2＇,4,4＂,5＇-tetracarboxylic acid; NMP=N-methyl-2-pyrrolidone） have been synthesized and structurally characterized. In 1-3, two Ln3＋ ions are doubly-bridged by two oxygen atoms of two carboxylate groups to form the dinuclear Lnz（Oco ）a unit. Each Ln2（Ocoo ）2 unit links with four H2L2 ligands and four L4- ligands to lead to the 3D framework, which can be rationalized as a new trinodal 4,4,8-connected （44.62）（45.6）（412.616） topological network by considering the dinuclear Ln2（Ocoo ）2 units as 8-connected nodes and L4-/H2L2- ligands as planar 4-connected nodes, respectively. 1 and 3 exhibit blue emission originated from the ligand with the emission maximum at 384 nm, while 2 shows intense characteristic red emission of Eu3＋ ions and weak ligand-centered emission. Moreover, 2 has fluorescent quenching response towards the aromatic nitro compounds, especially for the 3,4-dinitrotoluene （3,4-DNT） with the linear Stern-Volmer relationship in the concentration range of 0-1 mM and the quenching constant （Ksv） of 2.084-103 M 1.
基金Project partially supported by US NSF grant CHE-1800392(AdBD)The authors thank Dr.Chad Park for assistance with the photophysical studies.We also acknowledge the Arizona Laboratory for the use of the ICP-MS supported by NIEHS Grant(P42 ES-04940-11).
文摘Two series of lanthanide-containing metal-organic frameworks(Ln-MOFs)of the general formula{[Ln(HIDA)_(2)H_(2)O]ClO_(4)·H_(2)O}_n(Ln=La(1),Nd(2),Eu(3),Gd(4),Tb(5),Eu:Tb(6);H_(2)IDA=iminodiacetic acid)and[Ln(TT)(HTT)(H_(2)O)_3]_n(Ln=Eu(7),Gd(8),Tb(9),Dy(10),and Eu:Tb(11);H_(2)TT=tartaric acid)were synthesized by reacting Ln(ClO_(4))_3 with iminodiacetic acid and L-tartaric acid,respectively.All compounds were structurally characterized by single-crystal X-ray diffraction.Elemental analyses are co nsistent with the corre sponding crystallographically generated formulas.Mo reover,the luminescence properties of both the single and mixed-lanthanide complexes were studied.Near infrared,red,and green emissions that are characteristic of Nd(Ⅲ),Eu(Ⅲ),and Tb(Ⅲ)are observed for 2,3/7,and 5/9,respectively.For the two mixed-lanthanide complex systems 6 and 11,depending on the relative amount of Eu(Ⅲ)and Tb(Ⅲ),the color of emission can be fine-tuned.It is found that a small amount of Eu(Ⅲ)is adequate for the observation of the most intense transition of Eu(Ⅲ).This is believed to be a result of energy transfer from Tb(Ⅲ)to Eu(Ⅲ)within the same complex-a conclusion supported by the significantly shortened lifetime of Tb(Ⅲ)and the accompanying enhanced lifetime of Eu(Ⅲ)in the mixedlanthanide complex with respect to the corresponding values for the pure Tb(Ⅲ)and Eu(Ⅲ)complexes with the same ligand.
