RESUMO
Multicolor-tunable room-temperature phosphorescence (RTP) is attracting wide attention in optoelectronic applications. Here, we propose a coordination-oriented assembly approach to achieve wide-range RTP with a benzimidazole derivative (2,7-diazabenzimidazole, DZBIM) as a luminogen. These two compounds exhibit unexpected excitation-responsive RTP emission, and the phosphorescence emission nearly covers the entire visible region with the change of the excitation wavelength from 360 to 620 nm. To the best of our knowledge, this is the first report of coordination polymers with such a full-color-tunable RTP. Compound 1 also shows white-light emission upon excitation at 280 nm. Experimental and theoretical results demonstrate that multiple intermolecular interactions and emission centers from different aggregates are responsible for the generation of multicolor emission. The white-light emission and multiple anticounterfeiting are explored. Besides, compound 1 exhibits high antibacterial activity benefiting from efficient 1O2 generation. This work provides an efficient way to prepare a color-tunable RTP.
RESUMO
Designing novel multifunctional rare-earth metal-organic frameworks (MOFs) has attracted intensive attention. In particular, employing such materials for sensing or catalytic reactions is still very challenging. Here, a new 3D porous Eu(iii)-MOF, [Eu(cppa)(OH)]·xS (denoted as CTGU-19, S = solvent molecule, CTGU = China Three Gorges University), was synthesized by using 5-(4-carboxyphenyl)picolinic acid (H2cppa) as an organic ligand, and it shows a 3D (3,12)-connected topological net with the point symbol (420·628·818)(43)4, constructed from cubane-shaped tetranuclear europium building units. Interestingly, CTGU-19 can be used as a highly sensitive luminescent sensor to identify ornidazole (ODZ) and nitrofurantoin (NFT) at different excitation wavelengths. This result represents the first example of a lanthanide-metal-organic-framework (Eu-MOF) that can be employed as a discriminating fluorescent probe to recognize ODZ and NFT at different excitation wavelengths. Furthermore, after loading CTGU-19 with Ag and/or Au nanoparticles, the composites exhibit efficient catalytic performance for reducing 2-/3-/4-nitrophenols (2-/3-/4-NP), in which the unit mass reduction rate constants of Ag0.8Au0.2@CTGU-19 for 2-NP, 3-NP, and 4-NP reach 68.8, 53.80, and 52.34 s-1 g-1, respectively.
RESUMO
Three-fold interpenetrating Zn(ii) MOF with the dense π-stacking of flexible ligands exhibit long-lived phosphorescence emission up to 91 ms at room temperature. Photoelectric measurements show efficient electro-hole separation based on the long lifetime of triplet state exciton.
RESUMO
An alkali-resistant Zn-MOF directed by [BMI]Br ionic liquid, (BMI)2[Zn3(ptptc)2] (1), based on a π-electron-rich terphenyl-tetracarboxylic acid, has been synthesized under the combination of hydro/solvothermal and ionothermal condition (BMI = 1-butyl-3-methylimidazolium, H4ptptc = p-terphenyl-3,3'',5,5''-tetracarboxylic acid). In 1, the trinuclear Zn(ii) clusters are linked by the organic moieties of the ptptc ligands, resulting in a 3D anionic framework structure with highly disordered [BMI]+ cations filled in the pores. 1 exhibits good chemical stability in water and NaOH solutions (pH range of 7-12), which allow it to detect antibiotics and nitroaromatic explosives in an aquatic system. 1 represents high fluorescence quenching efficiency toward NFs (furazolidone, FZD; nitrofurazone, NZF; nitrofurantoin, NFT), NMs (ronidazole, RDZ; metronidazole, MDZ; dimetridazole, DTZ; ornidazole, ODZ) and nitrophenol (2-nitrophenol, 2-NP; 3-nitrophenol, 3-NP; 4-nitrophenol, 4-NP; 2,4,6-trinitrophenol, TNP) in water solution, respectively.
RESUMO
Four new different porous crystalline Cd(II)-based coordination polymers (CPs), i. e., [Cd(mdpt)2]·2H2O (1), [Cd2(mdpt)2(m-bdc)(H2O)2] (2), [Cd(Hmdpt)(p-bdc)]·2H2O (3), and [Cd3(mdpt)2(bpdc)2]·2.5NMP (4), were obtained successfully by the assembly of Cd(II) ions and bitopic 3-(3-methyl-2-pyridyl)-5-(4-pyridyl)-1,2,4-triazole (Hmdpt) in the presence of various benzendicarboxylate ligands, i.e., 1,3/1,4-benzenedicarboxylic acid (m-H2bdc, p-H2bdc) and biphenyl-4,4'-bicarboxylate (H2bpdc). Herein, complex 1 is a porous 2-fold interpenetrated four-connected 3D NbO topological framework based on the mdpt- ligand; 2 reveals a two-dimensional (2D) hcb network. Interestingly, 3 presents a three-dimensional (3D) rare interpenetrated double-insertion supramolecular net via 2D ···ABAB··· layers and can be viewed as an fsh topological net, while complex 4 displays a 3D sqc117 framework. Then, the different gas sorption performances were carried out carefully for complexes 1 and 4, the results of which showed 4 has preferable sorption than that of 1 and can be the potential CO2 storage and separation material. Furthermore, the stability and luminescence of four complexes were performed carefully in the solid state.
RESUMO
The highly porous luminescent metal-organic frameworks (MOFs) can act as fluorescent probes for the detection of nitro compounds and can also serve as containers and energy transfer platforms to construct the host-guest systems. Herein, two new three-dimensional MOFs with high porosity were prepared successfully by the electron-rich tetrakis(4-pyridylphenyl)ethylene (tppe) as ligands. Compound 1 shows the high sensitivity and selectivity toward nitro-antibiotics in an aqueous media, particularly showing the best detection efficiency for furazolidone (FZD) among the reported luminescent sensors. The highly efficient fluorescence quenching toward FZD may be attributed to the electron and energy transfer. Compound 2 has naphthalene-2,7-dicarboxylic acid (2,7-npd) and tppe as dual linkers, and the energy transfer between 2,7-npd and tppe leads to the emission band in a large scale. It is worth noting that the single-phased white-light materials can be obtained by the in situ encapsulation of different concentration of sulforhodamine 101 (SR101) into compound 2 matrix.
Assuntos
Antibacterianos/análise , Substâncias Luminescentes/química , Estruturas Metalorgânicas/química , Nitrocompostos/análise , Estilbenos/química , Cristalografia por Raios X , Luminescência , Medições Luminescentes , Modelos Moleculares , Rodaminas/químicaRESUMO
Effective detection of organic/inorganic pollutants, such as antibiotics, nitro-compounds, excessive Fe3+ and MnO4 - , is crucial for human health and environmental protection. Here, a new terbium(III)-organic framework, namely [Tb(TATAB)(H2 O)]â 2H2 O (Tb-MOF, H3 TATAB=4,4',4''-s-triazine-1,3,5-triyltri-m-aminobenzoic acid), was assembled and characterized. The Tb-MOF exhibits a water-stable 3D bnn framework. Due to the existence of competitive absorption, Tb-MOF has a high selectivity for detecting Fe3+ , MnO4 - , 4-nirophenol and nitroimidazole (ronidazole, metronidazole, dimetridazole, ornidazole) in aqueous through luminescent quenching. The results suggest that Tb-MOF is a simple and reliable reagent with multiple sensor responses in practical applications. To the best of our knowledge, this work represents the first TbIII -based MOF as an efficient fluorescent sensor for detecting metal ions, inorganic anions, nitro-compounds, and antibiotics simultaneously.
RESUMO
A water-stable cationic MOF could be used as a single crystal container to capture Cr(vi)-oxyanions via ion exchange with high capacity and selectivity. It is the first report that demonstrates that CrO42- ions could be traced and confirmed via a single-crystal to single-crystal (SC-SC) pattern.
RESUMO
Three isostructural metal-organic frameworks denoted as Zn(L)(aip)·(H2O) (1), Zn(L)(ip)·(DMF)(H2O)1.5 (2), and Zn(L)(HBTC)·(H2O)2 (3) with functional groups -NH2, -H and -COOH, respectively, decorated on the 1D channels have been rationally designed with the purpose of exploring the influence of electron transfer from organic ligands in the 1D channels on the sensing of nitro explosives and antibiotics. These three compounds exhibit strong fluorescence in water, and they can be applied to detect the presence of explosives or antibiotics by means of fluorescence quenching in aqueous solution, whereas in terms of special explosives or antibiotics at the same concentration, 3 demonstrates a more superior quenching efficiency than 1 and 2. More importantly, it has been found that the difference in the sensing performances of these compounds is closely related to the interaction between the functional groups and guest molecules via electron and energy transfer from MOFs to explosives and antibiotics.
Assuntos
Antibacterianos/análise , Engenharia Química/métodos , Substâncias Explosivas/análise , Estruturas Metalorgânicas/química , Nitrocompostos/análise , Zinco/química , Antibacterianos/química , Elétrons , Transferência de Energia , Substâncias Explosivas/química , Fluorescência , Ligantes , Estruturas Metalorgânicas/síntese química , Nitrocompostos/química , Ácidos Ftálicos/química , Quinolinas/química , Ácidos Tricarboxílicos/química , Água/químicaRESUMO
Two pH-stable luminescent metal-organic frameworks (LMOFs), {[Ln2(L)2(OH)(HCOO)]·[H2O]}n (Ln = Eu 1, Tb 2), based on a new π-conjugated organic building block involving both carboxylate and terpyridine groups were rationally synthesized under a combination of hydro/solvothermal and ionothermal conditions (H2L = 4'-(4-(3,5-dicarboxylphenoxy)phenyl)-4,2':6',4''-terpyridine). 1 and 2 are isostructural and feature noninterpenetrated open 3D condensed frameworks constructed by rod-shaped lanthanide-carboxylate building units. Their excellent water-stability and pH-stability allow them to be used in aquatic systems. 1 and 2 both exhibit selective and sensitive aqueous phase detection of the well-known nitroaromatic explosive environmental pollutant 2,4,6-trinitrophenol (TNP), which is highly desirable for practical applications. The presence of a free pyridine group on the LMOF particle surface was strategically utilized for the purpose of exclusive TNP-sensing.
RESUMO
A super-stable multifunctional terbium(iii)-organic framework, namely {[Tb(TATAB) (H2O)2]·NMP·H2O}n (Tb-MOF, H3TATAB = 4,4',4''-s-triazine-1,3,5-triyltri-m-aminobenzoic acid, NMP = N-methyl-2-pyrrolidone) was synthesized. Tb-MOF exhibits a 2D sql structure with binuclear [Tb2(COO)4(H2O)4]2+ units as 4-connected nodes, and free water and NMP molecules are inserted between 2D layers through hydrogen-bonding interactions, forming a sandwich-type architecture. Observably, such a framework remains intact in a remarkable variety of environments such as common solvents and aqueous solutions with metal cations and inorganic anions, as well as with a pH ranging from 1 to 13. In particular, Tb-MOF can not only detect small organic molecules, metal cations and inorganic anions with high sensitivity and high selectivity, but also can accurately detect explosive 2-nitrophenol, 3-nitrophenol, 4-nitrophenol and 2,4,6-trinitrophenol in water. Its luminescence quenching response to Fe3+ and Cr2O72- ions can be explained in terms of the competitive absorption mechanism. In addition, the luminescence intensity of Tb-MOF is strongly correlated with the pH value in a pH range from 1 to 13. Thus, this material can be potentially used as a multi-responsive luminescent sensor.
RESUMO
Six new Co(ii)-based mixed-ligand coordination polymers, namely, [Co2(H3bppc)2(2,2'-bpy)4]·H2O (), [Co2(Hbppc)(2,2'-bpy)2(H2O)]·H2O (), [Co(H2bppc)(H-bpp)]·2H2O (), [Co3(µ3-OH)(bppc)(dps)(CH3CH2OH)]·4H2O (), [Co2(bppc)(bib)(H2O)4]·(H2-bib)0.5·(H2O)3 (), and [Co2(Hbppc)(bix)2]·2H2O (), (H5bppc = biphenyl-2,4,6,3',5'-pentacarboxylic acid, 2,2'-bpy = 2,2'-bipyridine, bpp = 1,3-bis(4-pyridyl)propane, dps = 4,4'-sulfanediyldipyridine, bib = 1,4-bis(imidazol-1-yl)benzene, bix = 1,4-bis(imidazol-1-ylmethyl)benzene), have been obtained under solvothermal conditions. exhibits a 3D supramolecular framework based on a [Co2(H3bppc)2(2,2'-bpy)4] unit. has a (3,4)-connected dmc net with a (4·8(2))(4·8(5)) topology containing alternate binuclear metal clusters and single metal centres. shows a 3D supramolecular architecture constructed from ladder-like arrays decorated with H-bpp. exhibits a binodal (5,7)-connected 3D network based on trinuclear [Co3(µ3-OH)](5+) units with an unusual (3·4(6)·5(2)·6)(3(2)·4(6)·5(7)·6(5)·7) topology. features a (4,6)-connected 3D fsc open framework with binuclear [Co2(H2O)(COO)](3+) units as nodes, and H2-bib and water molecules located in the voids of its framework by hydrogen bonds. possesses a 3D net containing unusual 2D polyrotaxane sheets. Topological analysis reveals that has a (3,4,4)-connected 3D network with a (4·6·7(4))(4·6·7)(6·7(2)·10(2)·11) topology. The structural difference of and is due to the different pH values of the reaction system. Though complexes were synthesised under similar reaction conditions, the carboxylic groups of H5bppc were partially deprotonated in , and and fully deprotonated in and . Complexes display diverse structures depending on different N-donor ligands and the coordination modes of the multicarboxylate ligand. Variable-temperature magnetic susceptibility measurements reveal that complexes show antiferromagnetic interactions.
RESUMO
A pair of 3-D homochiral metal-organic frameworks (HMOFs) based on a mixed semi-rigid 5-(2-carboxypyrrolidine-1-carbonyl)isophthalate (PIA) ligand and rigid 4,4'-bipyridine (bipy), [Co3((R)-PIA)2(bipy)3]·6H2O (1-D) and [Co3((S)-PIA)2(bipy)3]·6H2O (1-L) are synthesized and structurally characterized. They are enantiomers and exhibit three-dimensional open frameworks. In each structure, the PIA ligands link the Co centers into homochiral frameworks with large open channels that are occupied by the bipy ligands. Interesting helical chains built from the connectivity between PIA ligands and Co centers are presented. Antiferromagnetic coupling is observed in 1-D. These results demonstrated that the mixed ligand approach is successful for the construction of HMOFs.
Assuntos
Cobalto/química , Compostos Organometálicos/química , Prolina/química , Piridinas/química , Cristalografia por Raios X , Ligantes , Modelos Moleculares , Conformação Molecular , Compostos Organometálicos/síntese química , Ácidos Ftálicos/síntese química , Ácidos Ftálicos/química , Piridinas/síntese química , Pirrolidinas/síntese química , Pirrolidinas/química , EstereoisomerismoRESUMO
Five new coordination polymers, namely, [Mn(2,2'-bipy)(H2O)2(H2L1)]n (1), {[Co(btb)(H2O)2(H2L1)]·0.5H2O}n (2), [Co(bib)(H2O)2(H2L1)]n (3), [Ni2(bpm)(H2O)3(L2)]n (4), and {[Co2(H2O)3(OH)(HL2)]·H2O}n (5), (H4L1 = 1,1':2',1''-terphenyl-4,4',4'',5'-tetracarboxylic acid, H4L2 = 1,1':2',1''-terphenyl-3,3'',4',5'-tetracarboxylic acid, 2,2'-bipy = 2,2'-bipyridine, btb = 1,4-bis(1,2,4-triazol-1-yl)butane, bib = 1,4-bis(imidazol-1-yl)butane, bpm = bis(4-pyridyl)amine), have been obtained under hydrothermal conditions. Complex 1 exhibits a 3D supramolecular framework based on 1D chains. Both complexes 2 and 3 are 3D supramolecular frameworks constructed from 1D zig-zag chains. Complex 4 features a 3D tetra-nodal (3,4,4,5)-connected architecture containing 1D µ-COO bridged chains with (5(2)·6(2)·7.9)(5(2)·6(4)·7(3)·8)2(5(2)·6)2(6(3)·7(2)·9) topology. Complex 5 shows a 3D penta-nodal (3,4,4,6,6)-connected net containing 1D µ-OH/µ-COO bridged chains and mononuclear Co(II) nodes with a (4(2)·6(3)·8)(4(3))2(4(4)·6(2))2(4(4)·6(6)·8(5))2(4(4)·6(7)·8(4)) topology. Variable-temperature magnetic susceptibility measurements reveal that complexes 2 and 3 show antiferromagnetic interactions between the adjacent Co(II) ions, whereas 4 is a ferromagnetic system.
RESUMO
Two new Co(II) based metal-organic frameworks, namely {[Co5(µ3-OH)2(m-pda)3(bix)4]·2ClO4}n (1) and {[Co2(p-pda)2(bix)2(H2O)]·H2O}n (2), were prepared by hydrothermal reactions of Co(II) salt with two isomeric dicarboxyl tectons 1,3-phenylenediacetic acid (m-pda) and 1,4-phenylenediacetic acid (p-pda), along with 1,3-bis(imidazol-L-ylmethyl)benzene (bix). Both complexes 1 and 2 have been characterized by elemental analysis, IR spectroscopy, single-crystal X-ray diffraction, powder X-ray diffraction (PXRD), and thermogravimetric analysis (TGA). 1 shows a 6-connected 3-D pcu cationic framework with pentanuclear [Co5(µ3-OH)2(COO)6(bix)2](2+) units, while 2 exhibits a 6-connected 3-D msw net based on [Co2(µ2-H2O)(COO)2](2+) clusters. The results indicate that the different dispositions of the carboxylic groups of dicarboxylates have an important effect on the overall coordination frameworks. Perchlorate anions in 1 can be partly exchanged by thiocyanate and azide anions, however they are unavailable to nitrate anions. Magnetic susceptibility measurements indicate that both 1 and 2 show weak antiferromagnetic interactions between the adjacent Co(II) ions.
RESUMO
Five new Mn(II) coordination polymers, namely [Mn(2)(tbip)(2)(bix)] (1), [Mn(3)(tbip)(3)(bix)(2)] (2), [Mn(3)(tbip)(2)(Htbip)(2)(bib)(2)]·4H(2)O (3), [Mn(4)(tbip)(4)(bbp)(2)(H(2)O)(2)] (4), and [Mn(4)(tbip)(4)(bip)]·2H(2)O (5), were prepared by hydrothermal reactions of Mn(II) acetate with H(2)tbip (5-tert-butyl isophthalic acid) in the presence of different di-imidazolyl coligands (bix =1,4-bis(imidazol-1-ylmethyl)benzene, bib =1,4-bis(imidazol) butane, bbp =1,3-bis(benzimidazol)propane, bip =1,3-bis(imidazol)propane). All complexes were characterized by elemental analysis, IR spectra, thermogravimetric analysis, single-crystal X-ray crystallography, and powder X-ray diffraction. Single crystal X-ray studies show that these coordination polymers contain homometallic clusters varying from dimeric, trimeric, and tetrameric motifs to polymeric chains depending upon the coligands used. Complex 1 has a 3D 6-connected polycatenane network with dinuclear [Mn(2)O(2)] secondary building units. Complex 2 possesses a 3D 8-connected structure with trinuclear [Mn(3)(COO)(6)] units. Complex 3 shows a 3D pcu net based on trinuclear [Mn(3)(COO)(6)] clusters as nodes. Complex 4 features a 3D 8-connected structure constructed from the distorted square-grid tetranuclear [Mn(4)(µ(2)-COO)(8)(µ(2)-H(2)O)] units. Complex 5 shows a 3D (4,5,6)-connected net containing 1D µ-O/µ-COO alternately bridged chains. Magnetic susceptibility measurements indicate that complexes 1 and 3-5 show weak antiferromagnetic interactions between the adjacent Mn(II) ions, whereas 2 is a three-spin center homometallic ferromagnetic system.
RESUMO
Two novel 3-D coordination polymers with different Cu(II) subunits as nodes and mixed bridging ligands as linkers, namely [Cu(5)(µ(3)-OH)(2)(1,3-bip)(2)(CH(3)O-ip)(4)](n) (1) and {[Cu(4)(1,3-btp)(2)(CH(3)O-p)(4)(H(2)O)(2)]·2H(2)O}(n) (2) (CH(3)O-H(2)ip = 5-methoxyisophthalate, 1,3-bip = 1,3-bis(imidazol)propane, 1,3-btp = 1,3-bis(1,2,4-triazol-1-yl)propane), were prepared under hydrothermal conditions. Complex 1 exhibits a CsCl-type network with [Cu(5)(µ(3)-OH)(2)](8+) clusters acting as nodes, which represents the first 3-D network based on pentanuclear Cu(II) clusters. Complex 2 features a 3-D pillared-layer network with (4,6)-connected (4(4).6(2))(4(4).6(8).8(3))-fsc topology, which is a rare example of homometallic coordination polymers constructed by alternate binuclear metal clusters and single metal centres. Variable-temperature magnetic susceptibility measurements show dominant ferromagnetic interactions in the pentanuclear clusters of 1 and strong antiferromagnetic interactions in the dinuclear paddle-wheel units of 2.