DOI: 10.1002/chem.201501193
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& Metal–Organic Frameworks |Hot Paper|
A Series of Lanthanide Metal–Organic Frameworks with Interesting Adjustable Photoluminescence Constructed by Helical Chains Ying Liu,[a] Yu Zhang,[a] Gong Hao Hu,[a] Shuai Zhou,[a] Ruiqing Fan,[b] Yulin Yang,[b] and Yan Xu*[a, c] Abstract: Based on the isonicotinic acid (HIN = pyridine-4carboxylic acid), seven lanthanide metal–organic frameworks (MOFs) with the formula [Ln(IN)2L] (Ln = Eu (1), Tb (2), Er (3), Dy (4), Ho (5), Gd (6), La (7), L = OCH2CH2OH) have been synthesized by mixing Ln2O3 with HIN under solvothermal conditions, and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, infrared spectroscopy, and fluorescence spectroscopy. Crystal structural analysis shows that compounds 1–6 are isostructural, crystallize in a chiral space
Introduction During the past decades, lanthanide materials were playing an important role in the field of advanced materials because of their intriguing applications such as catalysis,[1] magnetism,[2] luminescence,[3] and so on. Simultaneously, MOFs have been of intense interest not only due to their diverse structural flexibility,[4] but also because of their superior and broad applications in many research fields such as optical devices,[5] gas storage,[6] adsorption,[7] magnetism,[8] and catalysis.[9] Recently, an increasing number of Ln MOFs which adopt doping lanthanide ions in MOFs have been well announced.[10] It appears that the luminescent intensity will be improved, the quantum efficiency will also be enhanced, because concentration quenching effect will be dispelled or decreased. The luminescent Ln MOFs show a great potential as fluorescent material because the rare-earth ions are of a very rich electronic energy level. Also, in these materials, the emission can be obtained by a fluorescence of the conjugate ligand, mainly by the use of lanthanides. The ex[a] Y. Liu, Y. Zhang, G. H. Hu, S. Zhou, Prof. Y. Xu State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (P.R. China) E-mail: [email protected] [b] Prof. R. Fan, Y. Yang Department of Applied Chemistry Harbin Institute of Technology, Harbin 150001 (P.R. China) [c] Prof. Y. Xu State Key Laboratory of Coordination Chemistry Nanjing Tech University, Nanjing 210093 (P.R. China) Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/chem.201501193. Chem. Eur. J. 2015, 21, 10391 – 10399
group P212121, whereas compound 7 crystallizes in space group C2/c. Nevertheless, they all consist of new intertwined chains. Simultaneously, on the basis of the above-mentioned compounds, we have realized a rational design strategy to form the doped Ln MOFs [(EuxTb1¢x)(IN)2L] (x = 0.35 (8), x = 0.19 (9), x = 0.06 (10)) by utilizing TbIII as the second “rareearth metal”. Interestingly, the photoluminescence of [(EuxTb1¢x)(IN)2L] are not only adjustable by the ratios of Eu/ Tb, but also temperature or excitation wavelength.
citation can profit from “antenna effects”,[11] that is, the conjugate ligand is excited primarily, then transfer the energy to the luminescence centers. In addition, the guest solvent molecules can also conduce to the luminescence. In the previous literatures, a quantity of doped Ln MOFs have been reported.[12] It is not difficult to find that the Ln ions of most reported doped Ln MOFs are luminescent ions.[13] As we know, due to their red and green light emission, Eu3 + and Tb3 + become main ingredients for rare-earth trichromatic lamp with fluorescent powder. Recently, Cahill et al. reported the Tb3 + center sensitize the Eu3 + , effectively enhance Eu3 + emission in hetero-lanthanide coordination polymers.[14] Enhancement of Eu, while quenching of Tb emissions in [(Eu0.1:Tb99.9)2(2, 2-biphenate)3(H2O)2], has been reported by Williams et al.[15] In this paper, HIN is employed as ligand, choosing HIN as the ligand is based on the following considerations: 1) HIN is a pyridine-carboxylic acid, which is a heterocyclic acid with a conjugated structure and easily coordinated to metals to form compound; 2) The carboxylate group of HIN is able to provide diverse bonding modes to bridge adjacent LnIII ions; 3) As one type of polydentate ligand, the N and O atoms of HIN are locating in the opposite sites of the pyridine ring, which can make HIN act as an excellent linear ligand. In addition, the solvent (ethanediol) also act as a ligand, which compensates the charge and stabilizes the structure. Herein, we report seven new one-dimensional Ln MOFs, [Ln(IN)2L] (Ln = Eu (1), Tb (2), Er (3), Dy (4), Ho (5), Gd (6), La (7)) with two kinds of new helices. Then we successfully synthesized three doped Ln MOFs [(EuxTb1¢x)(IN)2L] (x = 0.35 (8), x = 0.19 (9), x = 0.06 (10)) by using TbIII as the second “rare-earth metal”. Lumines-
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Full Paper cent properties of the doped Ln MOFs were studied. Interestingly, the photoluminescence of [(EuxTb1¢x)(IN)2L] is not only adjustable by the ratios of Eu/Tb, but also through the temperature and excitation wavelengths.
Results and Discussion Synthesis Recently, the hydrothermal/solvothermal synthesis method has been a primary method in the synthesis of Ln MOFs. As we know, many factors can influence the growth of crystals, such as initial reactants, pH values, starting concentrations of reactants, solvents, reaction temperature, and time. In our case, solvent (ethanediol) plays an important role in the formation of compounds 1–10. It not only acts as the solvent, but also as a ligand, which can compensate the charge and establish a stable structure. The rod-like compounds 1–7 and the doped-lanthanide species 8–10 were prepared by rare-earth oxides, HIN, and HCOOH in ethanediol. Although HCOOH is not included in the final products, but we cannot obtain the above 10 compounds without HCOOH. The above compounds, including doped 8, 9, and 10, could be easily obtained under solvothermal synthesis and have good reproducibility.
Figure 1. a) View of the asymmetric unit of compound 1; b) Coordination mode of ErIII center.
Crystal structure Single crystal structural analyses reveal that compounds 1–6 and 8–10 crystallize in the orthorhombic, a chiral space group P2(1)2(1)2(1), they are isostructural, whereas compound 7 crystallizes in the monoclinic space group C2/c. Although formulas for ten compounds are very similar, the structures of compounds 1–6 and 8–10 are different to 7 due to the different symmetries. Thus here compounds 1 and 7 are described in detail as representations. As shown in Figure 1 a, the asymmetric unit of compound 1 consists of one crystallographically independent EuIII ion, two IN¢ ligands, and one L¢ anion. The EuIII ion is nine-coordinated by three oxygen atoms from two different L¢ ligands and six oxygen atoms from four different IN¢ligands to form a tricapped trigonal prism coordination geometry, in which the atoms O(1) and O(2) are located at the capping positions (Figure 1 b). The bond lengths of Eu¢O range from 2.305(2) to 2.873(4) æ, whereas the bond angles of O-Eu-O are between 47.83(11) and 151.28(8) 8. All the bond lengths and bond angles are in accordance to the reported literatures.[16] Scheme 1 a and b shows the coordination modes of IN¢ and L¢ ligands in compound 1: It clearly shows two kinds of ligands IN¢ and L¢ in compound 1; the former coordinate to two LnIII ions in a m2h2 :h3 mode and the latter is connected to two LnIII ions in a m2h1:h2 mode. Compared with our previously reported 1D chain-like [Er((IN))3(H2O)2]n, they have both utilized HIN as supporting ligand, but in this paper, ethanediol has been introduced as another ligand, which can establish a stable structure.[17] Adjacent EuIII ions are connected to each other by a L¢ ligand, and two IN¢ ligands to form an “airplane” conformation (Figure 2 a). Chem. Eur. J. 2015, 21, 10391 – 10399
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Scheme 1. Coordination modes of a) IN¢ and b) L¢ ligands in compound 1; c) Coordination modes of IN¢ in compound 3.
Then, on the basis of this “airplane” conformation, along the a axis, infinite chain is formed by the europium polyhedral, which is shown in Figure 2 b. Interestingly, a Eu-O-C chiral helical chain is found in 1, the symmetry of helical chain is a 21 screw axis, in which O5, O6, and their symmetric partners form bonds with europium atoms to generate a helical chain (Figure 3). The Flack parameter of 1 is 0.003(16), which indicates that the absolute configuration is correct. The chiral helices are particularly rare in Ln MOFs, with a notable example being a zinc phosphate of [{Zn2(HPO4)4}{Co(dien)2}]·H3O.[18] As showing in Figure S2 (the Supporting Information), the packing view of compound 1 displays a 3D supermolecular structure built up by 1D chains further linked by hydrogen bonds. Figure 4 shows the kind of hydrogen bonds in the network are O¢H···N, which is formed through oxygen atoms of
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Figure 4. The hydrogen bonds between IN¢ ligands and L¢ ligands in the adjacent chains of compound 1.
Figure 2. a) Coordination modes of the adjacent EuIII ions in compound 1; b) the infinite chain based on an “airplane” conformation.
L¢ ligands and nitrogen atoms of IN¢ ligands, respectively. The distances of O1¢H1···N2a (¢x, 0.5 + y, ¢0.5¢z) is 2.671(5) æ. The details of hydrogen bonds of 1–10 are given in Table S5 (the Supporting Information). When the Eu2O3 was replaced by La2O3, a similar La-MOF was obtained. Compared with compound 1, singlecrystal XRD reveals that compound 7 crystallizes in the orthorhombic, space group C2/c. As shown in Figure 5, the asymmetric unit of 7 is similar to compound 1. And in compound 7, IN¢ ligands are in a m2-h2 :h3 mode (Scheme 1 c). Along the b axis, the infinite chain which is similar to the one of compound 1 is formed by the lanthanum polyhedral (Figure S2, the Supporting Information). Because of different symmetry, the structure of compound 7 can described in another way, as show in Figure 6. The structure of framework for 3 is consists of both land d-helical La¢O chains, whereas the two types of ¢[La¢O]n¢ chains are fitted together to form a new intertwined La¢O double ¢[Ln¢O]n¢ helices by sharing the LaIII ions. Figure 3. l-Helical EuO-C chain of compound 1.
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Figure 5. View of the asymmetric unit of compound 7.
Powder X-ray diffraction The measured and simulated powder X-ray diffraction (PXRD) patterns of 1–10 are shown in Figure S5 (the Supporting Information). The measured XRD patterns are in agreement with the calculated patterns, which indicate the phase purity of compounds 1–10. The difference in reflection intensities during collection of the experimental XRD data are probably due to the preferred orientation effect of the powder. IR spectrum The IR spectra of 1–10 are presented in Figure S6 (the Supporting Information). It is easy to notice that the IR spectra of 1–10 are analogous, and thus here we give a detailed analysis of compound 1. In the IR spectrum of compound 1, absorption between 568 and 767 cm¢1 correspond to the n (Eu¢O) vibra-
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Figure 6. a) l-Helical La¢O chain, b) d-Helical La¢O chain of compound 7.
tions. The characteristic bands for the pyridine ring are in the region of 1218–1585 cm¢1. A peak at 3383 cm¢1 can be ascribed to the stretching vibration of O¢H, whereas the peaks in the range of 1012–1093 cm¢1 correspond to the n (C¢O) vibrations; these peaks can demonstrate the presence of hydroxyl groups of ethanediol. The features are in accord with the reported compounds.[19]
Luminescence properties Due to the excellent luminescent properties of EuIII, TbIII and HIN, compounds 1–3 and 8–10 were investigated. The photoluminescence spectra are shown in Figures 7 and 8 for compounds 1–3 and 8–10, respectively. The solid state emission spectrum of compound 1 at room temperature was measured under excitation at 394 nm. The emission spectrum exhibits the characteristic transition of EuIII ion. Compound 1 shows five emission bands at 579, 589, 612, 655, and 702 nm, which can be assigned to 5D0 !7FJ (J = 0, 1, 2, 3, 4) with the 5D0 !7F2 emission as the dominant band. Only one emission line can be observed for the non-degenerated 5 D0 !7F0 transition, which in agreement with the having of one site of symmetry (Cs, Cn, or Cnv) for the europium within the compound. The 5D0 !7F1 transition is a parity-allowed magnetic dipole transition, which is almost independent of the host material and its intensity should vary with the crystal field strength acting on the EuIII ion. The 5D0 !7F2 transition is an electric dipole transition and intensively varies with the site symmetry of EuIII ions. The absence of the IN¢ ligand emission in the fluorescence spectra indicates an efficient energy transfer from the IN¢ ligands to the lanthanide centers, which can enhance the fluorescence efficiency, but also effectively reduces the loss of energy by radiationless thermal vibrations Chem. Eur. J. 2015, 21, 10391 – 10399
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Figure 7. Emission spectra of compounds 1–3.
and increases the rigidity of molecule. The above luminescent property is in agreement with the reported EuIII compounds.[20] The luminescent property of compound 2 was observed in the solid state at room temperature upon excitation at
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Figure 8. Excitation and emission spectra of compounds 8–10.
367 nm. The emission spectrum exhibits the characteristic transition of TbIII ion. Compound 2 shows four emission bands at 489, 546, 589, and 621 nm arising from the 5D4 !7FJ (J = 6, 5, 4, 3) with the 5D4 !7F5 emission as the dominant band, which is in agreement with those reported TbIII compounds.[21] Similar Chem. Eur. J. 2015, 21, 10391 – 10399
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to compound 1, there is also no emission arising from the IN¢ ligand. The solid-state emission spectrum of pure compound 3 at room temperature is measured under excitation at 338 nm. The maximum emission peaks at 379 and 403 nm among the emission bands in a range of 375–450 nm are ascribed to the coordinated IN¢ ligand, which displays a very weak emission at 431 nm corresponding to that caused by the exciting light at 330 nm. Compound 3 has a split peak due to the low symmetry of IN¢ ligands. The enhanced fluorescence efficiency of compound 3 can be attributed to the coordination of IN¢ and L¢ ligand to ErIII. The solid-state emission spectrum of pure compound 8 at room temperature is measured under excitation at 395 nm. The emission spectrum exhibits the characteristic transition of EuIII ion. Compound 8 also shows five emission bands at 579, 589, 612, 656, and 702 nm that can be assigned to 5D0 !7FJ (J = 0, 1, 2, 3, 4) with the 5D0 !7F2 emission as the dominant band. It is very similar to compound 1. In the emission spectrum, compound 8 displays the typical EuIII emission peaks, no emission bands for TbIII, and the ligand in the compound are observed. This indicates that the enhanced fluorescence intensity is due to the probability of the energy transfer from TbIII ion to EuIII ion and the coordination of IN¢ ligand to the LnIII ion. The solid-state emission spectrum of pure compound 9 at room temperature is measured at 378 nm. It shows six emission bands at 488, 547, 589, 613, 656, and 702 nm that can be assigned to 5D4 !7FJ (J = 6, 5, 4) and 5D0 !7FJ (J = 1, 2, 3, 4) with the 5D0 !7F2 emission as the dominant band. The emission band at 589 nm can not only be assigned to 5D4 !7F4 (J = 6, 5, 4), but also can be assigned to 5D0 !7F1 and the photoluminescence spectra of compound 9 not only exhibit the characteristic transition of EuIII ion, but also TbIII ion. In the emission spectrum, compound 9 displays the typical EuIII and TbIII emission peaks, no emission bands for the ligand in the compound are observed; this result clearly indicates that the HIN is an excellent antenna chromophore for sensitizing both the EuIII ion and the TbIII ion.[22] The solid-state emission spectrum of pure compound 10 at room temperature is measured under excitation at 370 nm. It shows four strong emission bands at 489, 545, 588, and 621 nm that can be assigned to 5D4 !7FJ (J = 6, 5, 4, 3), with the 5D4 !7F5 emission as the dominant band, which correspond to the characteristic transitions of TbIII and are very similar to compound 2. In the emission spectrum, compound 10 displays the typical TbIII emission peaks, no emission bands for EuIII, and the ligand in the compound is observed due to the fluorescence quenching when EuIII concentration is 2.23 %. So the enhanced fluorescence intensity is due to the energy transferred to Tb from IN¢ ligands. Compared with [Tb0.957Eu0.043(H2cpda)(Hcpda)(H2O)]·6 H2O (H3cpda: 5-(4-carboxyphenyl)-2,6-pyridinedicarboxylic acid) with adjustable photoluminescence reported by Cui et al.,[23] the formula [(EuxTb1¢x)(IN)2L] reported in this paper can readily generate tunable photoluminescence properties by changing EuIII/TbIII ratios. In addition, because Eu3 + and Tb3 + within the
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Full Paper sample emit different colors of red at 612 nm and green at 545 nm, respectively, the luminescence colors of [(EuxTb1¢x)(IN)2L] can also readily generate tunable colors from red to yellow, and green. The temperature-dependence of the emission spectrum of compounds 8–10 are investigated at 77 and 293 K in Figure 9. The luminescent intensity of both Tb3 + and Eu3 + in 8 and 9 increases as the temperature increases, which is due to the thermal activation of nonradiative-decay pathways.[23] Interestingly, compound 10 exhibits a significantly different luminescent behavior compared to those of 8 and 9. The emission intensity of the Tb3 + strongly decreases, whereas that of the Eu3 + emission increases as the temperature increases in 10. The temperaturedependent decreases of the Tb3 + emission could be attributed to the thermally driven phonon-assisted Fçrster transfer mechanism from the Tb3 + to Eu3 + ions. The solid state emission spectra of compound 10 are investigated under excitation at 295 and 370 nm at room temperature, respectively. In Figure 10, the emission spectrum exhibits the characteristic transition of EuIII ion and the luminescence color of compound 10 shows red under excitation at 295 nm, whereas the emission spectrum exhibits the characteristic transition of the TbIII ion and luminescence colors of compound 10 shows green under excitation at 370 nm. Because of the interesting phenomena, we chose the excitation at 295 nm to investigate the temperature-dependence of the emission spectrum. The dynamics of the Eu3 + and Tb3 + PL were measured at room temperature (Figure 11). All the lifetimes were successfully fitted by ways of a single exponential law (square correlation factor R2 > 0.99). From the decay curve of 5D0 !7F2 from Eu3 + in 1 under 295 nm excitation, the decay lifetime was determined to be 0.7117 ms; From the decay curve of 5D4 !7F5 from Tb3 + in 2 under 295 nm excitation, the decay lifetime was determined to be 1.3426 ms; From the decay curve of 5D0 !7F2 from Eu3 + in 8 under 295 nm excitation, the decay lifetime was determined to be 0.9969 ms; From the decay curve of 5 D0 !7F2 from Eu3 + in 9 under 300 nm excitation, the decay lifetime was determined to be 1.0275 ms; From the decay curve of 5D4 !7F5 from Tb3 + in 10 under 295 nm excitation, the decay lifetime was determined to be 1.1268 ms. From the above, along with the decrease of EuIII concentration, the time decay varies from 0.7117 ms in samples up to 1.3426 ms in the samples with the largest Tb concentrations.
Conclusion We have successfully synthesized seven new one-dimensional Ln MOFs and three doped EuIII/TbIII MOFs by using the solvothermal synthesis method. Under the same conditions, we have obtained two types of structures with different new helices. The frameworks of compounds 1–6 and 8–10 consist of one type of helical Ln¢O¢C chain; whereas in the structure of compound 7, l-and d-helical Ln¢O chains are observed. The luminescent investigation indicates that compounds 1–3 and 8–10 are excellent candidates for fluorescent materials, and the formula [(EuxTb1¢x)(IN)2L] can readily generate tunable phoChem. Eur. J. 2015, 21, 10391 – 10399
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Figure 9. Emission spectra of 8–10 recorded at 77 and 293 K excited at 296 nm.
toluminescence properties by changing the EuIII/TbIII ratios. This study can be applied to generate tunable luminescent properties in the visible region by selecting the appropriate ratios of doped luminescent lanthanide ions and metal–organic host materials. The temperature-dependence of the emission
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Full Paper Experimental Section Materials and methods All chemicals were of reagent grade and without further purification. The crystalline products were characterized by powder XRD, IR spectrum, and fluorescence spectrum. The elemental analysis (C, H, and N) were obtained using a PerkinElmer 2400 elemental analyzer. Powder X-ray diffraction data were performed on a Bruker D8 Advance diffractometer with CuKa radiation (l = 1.54056 æ), with a step speed of 0.1 8 per second. The infrared spectra were measured on a Nicolet Impact 410 Fourier transform IR (FTIR) spectrometer by using the pressed KBr pellet technique from 4000 to 450 cm¢1. The solid-state emission/excitation spectra were recorded on an FP-6500 spectrofluorimeter with a 450 W xenon lamp as the excitation source.
Syntheses
Figure 10. Solid state emission spectrum of compound 10 under excitation at 295 and 370 nm, respectively, at room temperature.
Synthesis of 1: A mixture of Eu2O3 (0.1936 g, 0.35 mmol) and ethanediol (8 mL) was stirred for 12 h at room temperature, then the mixture was transferred to a 25 mL Teflon reactor and heated under autogenous pressure at 170 8C for 7 days. After cooling to room temperature, colorless rod-like crystals were filtered off, washed with ethyl alcohol, and dried at room temperature for 24 h (yield 57 % based on Eu). IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (s), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for EuC14N2O6H13 : C 36.74, H 2.84, N 6.12; found: C 36.67, H 2.75, N 6.02.
Figure 11. Decay curves of compounds 1, 2, and 8–10.
spectrum of compound 10 exhibits a significantly different luminescent behavior that the emission intensity of the Tb3 + strongly decreases, whereas that of the Eu3 + emission increases as the temperature increases, which provides thoughts for designing various Ln MOFs for practically useful luminescent thermometers. Interestingly, luminescent properties of 10 are not only adjustable by temperature, but also excitation wavelength.
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Synthesis of 2: Compound 2 was prepared in a procedure similar to that of 1, except that Tb4O7 was utilized instead of Eu2O3 ; rodlike crystals were obtained. Yield: 47 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for TbC14N2O6H13 : C 36.19, H 2.80, N 6.03; found: C 36.25, H 2.76, N 5.97. Synthesis of 3: Compound 3 was prepared in a procedure similar to that of 1, except that Er2O3 was utilized instead of Eu2O3 ; pink rod-like crystals were obtained. Yield: 44 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for ErC14N2O6H13 : C 35.56, H 2.75, N 5.92; found: C 35.43, H 2.69, N 5.84. Synthesis of 4: Compound 4 was prepared in a procedure similar to that of 1, except that Dy2O3 was utilized instead of Eu2O3. Yield: 53 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for DyC14N2O6H13 : C 35.92, H 2.78, N 5.98; found: C 35.80, H 2.72, N 5.93. Synthesis of 5: Compound 5 was prepared in a procedure similar to that of 1, except that Ho2O3 was utilized instead of Eu2O3. Yield: 51 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for HoC14N2O6H13 : C 35.73, H 2.76, N 5.96; found: C 35.63, H 2.65, N 5.88. Synthesis of 6: Compound 6 was prepared in a procedure similar to that of 1, except that Gd2O3 was utilized instead of Eu2O3. Yield: 47 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs),
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Full Paper 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for GdC14N2O6H13 : C 36.32, H 2.81, N 6.05; found: C 36.17, H 2.77, N 6.11. Synthesis of 7: Compound 7 was prepared in a procedure similar to that of 1, except that La2O3 was utilized instead of Eu2O3. Yield: 54 %; IR (KBr): ~ n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for LaC14N2O6H13 : C 37.82, H 2.93, N 6.30; found: C 37.74, H 2.90, N 6.21.
least-squares technique on F2 with the use of the SHELX-2014/7 crystallographic software package. An empirical absorption correction was applied. The hydrogen atoms for CH2 and CH were located in calculated positions, whereas the H atom for OH was located from different map. All H atoms were assigned isotropic displacement parameters, whereas all the non-hydrogen atoms were refined anisotropically. The Ln occupancy factors of compounds 8-10 are fixed by Eu/Tb ratios of 0.35/0.65, 0.19/0.81 and 0.06/0.94, respectively, which are confirmed by energy-dispersive X-ray (EDX) analysis results as shown in Tables S1–S3 (the Supporting Information). Eu/Tb occupied one metal position was refined with the same coordinates and anisotropic thermal parameters.
Synthesis of 8: Compound 8 was prepared in a procedure similar to that of 1, except that using the doped Eu2O3 and Tb4O7 which the ratio of Eu2O3/Tb4O7 was 3:7 was utilized instead of Eu2O3. CCDC-1055231 (1), CCDC-1055232 (2), CCDC-1055233 (3), CCDCYield: 42 IR (KBr): ~ n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 1055234 (4), CCDC-1055235 (5), CCDC-1055236 (6), CCDC-1055237 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (7), CCDC-1055238 (8), CCDC-1055239 (9), and CCDC-1055240 (10) (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemencontain the supplementary crystallographic data for this paper. tal analysis calcd (%) for Eu0.35Tb0.65C14N2O6H13 : C 36.38, H 2.82, N These data can be obtained free of charge from The Cambridge 6.06; found: C 36.31, H 2.74, N 5.98. Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_reSynthesis of 9: Compound 9 was prepared in a procedure similar quest/cif. The crystallographic data and structure determination of to that of 8, except that the ratio of Eu2O3/Tb4O7 was 1:19. Yield: compounds 1–10 are summarized in Table 1. The selected bond 47 %; IR (KBr): ~ n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 Table 1. Crystal data and structure refinements for 1–10. (w), 1012 (w), 890 (w), 882 (w), 1 2 3 4 5 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental DyC14N2O6H13 HoC14N2O6H13 Formula EuC14N2O6H13 TbC14N2O6H13 ErC14N2O6H13 analysis calcd (%) for Mw 457.22 464.18 472.52 467.76 470.19 cryst. syst. orthorhombic orthorhombic orthorhombic orthorhombic orthorhombic Eu0.19Tb0.81C14N2O6H13 : C 36.30, H space group P2(1)2(1)2(1) P2(1)2(1)2(1) P2(1)2(1)2(1) P2(1)2(1)2(1) P2(1)2(1)2(1) 2.81, N 6.05; found: C 36.25, H a [æ] 7.1983(7) 7.2088(13) 7.1894(6) 7.1976(6) 7.2037(13) 2.80, N 5.99. Synthesis of 10: Compound 10 was prepared in a procedure similar to that of 8, except that the ratio of Eu2O3/Tb4O7 was 1:66. Yield: 50 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for Eu0.06Tb0.94C14N2O6H13 : C 36.22, H 2.80, N 6.04; found: C 36.04, H 2.74, N 5.97.
Single-crystal X-ray structure determination Single crystals of compounds 1– 10 were carefully selected under the microscope and mounted onto the tip of a thin glass fiber with epoxy glue for data collection. The collection of single-crystal X-ray analyses data were carried out on a Bruker Apex 2 CCD with graphite-monochromated MoKa radiation (l = 0.071073 æ) at 296(2) K using the w-2q scan method. The crystal structures were confirmed by direct methods and refined by full-matrix Chem. Eur. J. 2015, 21, 10391 – 10399
b [æ] c [æ] a [8] b [8] g [8] V [æ3] T [K] Z Rint data collected unique data GOF on F2 R1[a] [I > 2s(I)] wR2[b] (all data)
13.5912(13) 15.5938(14) 90 90 90 1525.6(2) 296(2) 4 0.0330 11 339 2928 1.020 0.0215 0.0462 6 formula GdC14N2O6H13 Mw 462.51 cryst. syst. orthorhombic space group P2(1)2(1)2(1) a [æ] 7.215(4) b [æ] 13.570(8) c [æ] 15.616(9) a [8] 90 b [8] 90 g [8] 90 V [æ3] 1528.8(15) T [K] 296(2) Z 4 Rint 0.0581 data collected 11 335 unique data 2949 GOF on F2 0.992 R1[a] [I > 2s(I)] 0.0279 wR2[b] (all data) 0.0515
13.542(3) 15.616(3) 90 90 90 1524.5(5) 296(2) 4 0.0250 11 298 2873 1.059 0.0208 0.0495 7 LaC14N2O6H13 444.17 orthorhombic C2/c 21.491(5) 7.4138(16) 20.282(4) 90 99.144(2) 90 3190.5(12) 296(2) 8 0.0373 11 378 3045 1.029 0.0250 0.0581
13.4890(11) 15.5931(13) 90 90 90 1512.2(2) 296(2) 4 0.0239 9891 2873 1.030 0.0153 0.0309 8 Eu0.35Tb0.65C14N2O6H13 461.75 orthorhombic P2(1)2(1)2(1) 7.2049(5) 13.5517(10) 15.6072(11) 90 90 90 1523.87(19) 296(2) 4 0.0203 11 290 2927 1.005 0.0138 0.0311
13.5132(11) 15.6057(12) 90 90 90 1517.9(2) 296(2) 4 0.0310 11 227 2926 1.000 0.0162 0.0368 9 Eu0.19Tb0.81C14N2O6H13 462.86 orthorhombic P2(1)2(1)2(1) 7.2026(6) 13.5416(11) 15.6011(12) 90 90 90 1521.6(2) 296(2) 4 0.0476 11 328 2908 1.042 0.0227 0.0438
13.510(2) 15.604(3) 90 90 90 1518.6(5) 296(2) 4 0.0531 11 061 2929 1.148 0.0369 0.0851 10 Eu0.06Tb0.94C14N2O6H13 463.77 orthorhombic P2(1)2(1)2(1) 7.2045(13) 13.534(2) 15.600(3) 90 90 90 1521.1(5) 296(2) 4 0.0248 11 290 2927 1.026 0.0160 0.0347
[a] R1 = S j j Fo j ¢ j Fc j j /S j Fo j . [b] wR2 = S[w(Fo2¢Fc2)2]/S[w(Fo2)2]1/2.
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Acknowledgements
[10]
We thank the NSFC (Grant 21171044 and 21371040), Natural Science Foundation of Jiangsu Province, China (Grant BK2012823), Graduate Education Innovation Project (KYLX_ 0740) and the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions. Keywords: helical structures · luminescence · metal–organic frameworks · lanthanides · X-ray diffraction [1] a) M. Shibasaki, N. Yoshikawa, Chem. Rev. 2002, 102, 2187; b) S. Jujjuri, E. Ding, S. G. Shore, M. A. Keane, Appl. Organomet. Chem. 2003, 17, 493; c) J. Inanaga, H. Furuno, T. Hayano, Chem. Rev. 2002, 102, 2211; d) J. S. Seo, D. Whang, H. Lee, S. I. Jun, J. Oh, Y. J. Jeon, K. Kim, Nature 2000, 404, 982. [2] a) S. Mukherjee, Y. H. Lan, G. E. Kostakis, R. Cl¦rac, C. E. Anson, A. K. Powell, Cryst. Growth Des. 2009, 9, 577; b) A. J. Tasiopoulos, T. A. O’Brien, K. A. Abbound, G. Christou, Angew. Chem. Int. Ed. 2004, 43, 345; Angew. Chem. 2004, 116, 349. [3] Y. Qiu, H. Liu, Y. Ling, H. Deng, R. Zeng, G. Zhou, M. Zeller, Inorg. Chem. Commun. 2007, 10, 1399. [4] a) M. Sakamoto, K. Manseki, H. Okawa, Coord. Chem. Rev. 2001, 219, 379; b) J. J. Perry Iv, J. A. Perman, M. J. Zaworotko, Chem. Soc. Rev. 2009, 38, 1400; c) J. Cheng, J. Zhang, S. Zheng, M. Zhang, G. Yang, Angew. Chem. Int. Ed. 2006, 45, 73; Angew. Chem. 2006, 118, 79; d) H. Furukawa, K. E. Cordova, M. O’Keeffe, O. M. Yaghi, Science 2013, 341, 1230444; e) T. R. Cook, Y. R. Zheng, P. J. Stang, Chem. Rev. 2013, 113, 734; f) M. O’Keeffe, O. M. Yaghi, Chem. Rev. 2012, 112, 675; g) M. Li, D. Li, M. O’Keeffe, O. M. Yaghi, Chem. Rev. 2014, 114, 1343. [5] a) B. Moulton, M. Zaworotko, Chem. Rev. 2001, 101, 1629; b) D. Braga, F. Grepioni, GR. Desiraju, Chem. Rev. 1998, 98, 1375; c) W. Zhang, R. G. Xiong, Chem. Rev. 2012, 112, 1163; d) O. Kahn, Acc. Chem. Res. 2000, 33, 647; e) D. F. Sava, L. E. S. Rohwer, M. A. Rodriguez, T. M. Nenoff, J. Am. Chem. Soc. 2012, 134, 3983; f) C. Wang, T. Zhang, W. Lin, Chem. Rev. 2012, 112, 1084; g) C. Y. Sun, X. L. Wang, X. Zhang, C. Qin, P. Li, Z. M. Su, D. X. Zhu, G. G. Shan, K. Z. Shao, H. Wu, J. Li, Nat. Commun. 2013, 4, 2717. [6] Q. R. Fang, G. S. Zhu, M. Xue, J. Y. Sun, Y. Wei, S. L. Qiu, R. R. Xu, Angew. Chem. Int. Ed. 2005, 44, 3845; Angew. Chem. 2005, 117, 3913. [7] a) X. Zhao, B. Zhao, Y. Ma, W. Shi, P. Cheng, Z. Jiang, D. Liao, S. Yan, Inorg. Chem. 2007, 46, 5832; b) B. Zhao, P. Cheng, Y. Dai, C. Cheng, D. Liao, S. Yan, Z. Jiang, G. Wang, Angew. Chem. Int. Ed. 2003, 42, 934; Angew. Chem. 2003, 115, 964. [8] a) H. Li, M. Eddaoudi, M. O’Keeffe, O. M. Yaghi, Nature 1999, 402, 276; b) O. M. Yaghi, H. Li, C. Davis, D. Richardson, T. L. Groy, Acc. Chem. Res. 1998, 31, 474. [9] a) W. Lin, O. R. Evans, R. Xiong, Z. Wang, J. Am. Chem. Soc. 1998, 120, 13272; b) J. Lee, O. K. Farha, J. Roberts, K. A. Scheidt, S. T. Nguyen, J. T. Hupp, Chem. Soc. Rev. 2009, 38, 1450; c) H. R. Moon, D. W. Lim, M. P.
Chem. Eur. J. 2015, 21, 10391 – 10399
www.chemeurj.org
[11]
[12]
[13]
[14] [15] [16]
[17] [18] [19]
[20]
[21]
[22] [23]
Suh, Chem. Soc. Rev. 2013, 42, 1807; d) M. Yoon, R. Srirambalaji, K. Kim, Chem. Rev. 2012, 112, 1196; e) L. Ma, C. Abney, W. Lin, Chem. Soc. Rev. 2009, 38, 1248; f) J. Zhang, A. V. Biradar, S. Pramanik, T. J. Emge, T. Asefa, J. Li, Chem. Commun. 2012, 48, 6541. a) B. Q. Ma, D. S. Zhang, S. Gao, Angew. Chem. Int. Ed. 2000, 39, 3644; Angew. Chem. 2000, 112, 3790; b) M. B. Zhang, S. T. Zheng, G. Y. Yang, Chin. J. Struct. Chem. 2005, 7, 816; c) X. J. Zhang, Y. H. Xing, Cryst. Growth Des. 2007, 7, 2041; d) Z. B. Han, X. N. Z. Cheng, Z. Anorg. Allg. Chem. 2005, 631, 937; e) L. Ma, O. R. Evans, B. M. Foxman, W. B. Lin, Inorg. Chem. 1999, 38, 5837; f) B. Yan, Q. Y. Xie, Inorg. Chem. Commun. 2003, 6, 1448; g) H. L. Gao, P. Cheng, Chin. J. Inorg. Chem. 2004, 20, 1145. a) J. M. Lehn, Angew. Chem. Int. Ed. Engl. 1990, 29, 1304; Angew. Chem. 1990, 102, 1347; b) Y. Zhang, L. Huang, H. Miao, H. Wan, H. Mei, Y. Liu, Y. Xu, Chem. Eur. J. 2015, 21, 3234. a) M. L. Ma, C. Ji, S. Q. Zang, Dalton Trans. 2013, 42, 10579; b) X. T. Rao, Q. Huang, X. L. Yang, Y. J. Cui, Y. Yang, C. D. Wu, B. L. Chen, G. D. Qian, J. Mater. Chem. 2012, 22, 3210; c) H. L. Guo, Y. Z. Zhu, S. L. Qiu, J. A. Lercher, H. J. Zhang, Adv. Mater. 2010, 22, 4190. a) Q. Tang, S. X. Liu, Y. W. Liu, D. F He, J. Miao, X.-Q. Wang, Y.-J. Ji, Z. P. Zheng, Inorg. Chem. 2014, 53, 289; b) Y. Zhang, L. Chen, W. W. Ju, Y. XU, Chem. Res. Chin. Univ. 2014, 30, 194; c) Y. Zhang, W. W. Ju, X. Xu, Y. Lv, D. R. Zhu, Y. XU, Cryst. Eng. Comm. 2014, 16, 5681. D. T. de Lill, A. de Bettencourt-Dias, C. L. Cahill, Inorg. Chem. 2007, 46, 3960. C. L. Choi, Y. F. Yen, H. H. Y. Sung, A. W. H. Siu, S. T. Jayarathne, K. S. Wong, I. D. Williams, J. Mater. Chem. 2011, 21, 8547. a) L. Chen, J. Y. Guo, X. Xu, W. W. Ju, D. Zhang, D. R. Zhu, Y. Xu, Chem. Commun. 2013, 49, 9728; b) D. W. Yan, L. Zheng, Z. B. Zhang, D. R. Zhu, Y. Xu, J. Coord. Chem. 2010, 63, 4215. L. J. Han, X. C. Sun, Y. L. Zhu, W. L. Zhou, Q. Chen, Y. Xu, J. Chem. Crystallogr. 2010, 40, 579. Y. Wang, J. H. Yu, M. Guo, R. R. Xu, Angew. Chem. Int. Ed. 2003, 42, 4089; Angew. Chem. 2003, 115, 4223. a) L. Zheng, Y. Xu, X. L. Zhang, Z. B. Zhang, D. R. Zhu, S. Chena, S. P. Elangovan, Cryst. Eng. Comm. 2010, 12, 694; b) W. W. Ju, D. Zhang, D. R. Zhu, Y. Xu, Inorg. Chem. 2012, 51, 13373; c) Y. Xu, S. Ding, X. J. Zheng, Solid. State. Chem. 2007, 180, 2020; d) W. Zhou, L. Chen, Y. Xu, Z. Anorg. Allg. Chem. 2013, 639, 947. a) C. Daiguebonne, N. Kerbellec, Y. G¦rault, O. J. Guillou, J. Alloys Compd. 2008, 451, 372; b) L. Zheng, X. M. Qiu, Z. B. Zhang, D. R. Zhu, Y. Xu, Inorg. Chem. Commun. 2011, 14, 906; c) Y. Zhu, X. Sun, D. R. Zhu, Y. Xu, Inorg. Chim. Acta 2009, 362, 2565. a) W. L. Zhou, Y. Xu, L. J. Han, D. R. Zhu, Dalton Trans. 2010, 39, 3681; b) H. Xu, X. Li, D. Yan, Inorg. Chem. Commun. 2008, 11, 1187; c) P. Mahata, K. V. Ramya, S. Natarajan, Dalton Trans. 2007, 4017; d) L. Zheng, X. M. Qiu, Y. Xu, J. Fu, Y. Yuan, D. R. Zhu, S. Chen, Cryst. Eng. Comm. 2011, 13, 2714. Y. J. Cui, H. Xu, Y. F. Yue, Z. Y. Guo, J. C. Yu, Z. X. Chen, J. K. Gao, Y. Yang, G. D. Qian, B. L. Chen, J. Am. Chem. Soc. 2012, 134, 3979. Y. J. Cui, W. F Zou, R. J. Song, J. C. Yu, W. Q. Zhang, Y. Yang, G. D. Qian, Chem. Commun. 2014, 50, 719.
Received: March 26, 2015 Published online on June 3, 2015
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& Metal–Organic Frameworks |Hot Paper|
A Series of Lanthanide Metal–Organic Frameworks with Interesting Adjustable Photoluminescence Constructed by Helical Chains Ying Liu,[a] Yu Zhang,[a] Gong Hao Hu,[a] Shuai Zhou,[a] Ruiqing Fan,[b] Yulin Yang,[b] and Yan Xu*[a, c] Abstract: Based on the isonicotinic acid (HIN = pyridine-4carboxylic acid), seven lanthanide metal–organic frameworks (MOFs) with the formula [Ln(IN)2L] (Ln = Eu (1), Tb (2), Er (3), Dy (4), Ho (5), Gd (6), La (7), L = OCH2CH2OH) have been synthesized by mixing Ln2O3 with HIN under solvothermal conditions, and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, infrared spectroscopy, and fluorescence spectroscopy. Crystal structural analysis shows that compounds 1–6 are isostructural, crystallize in a chiral space
Introduction During the past decades, lanthanide materials were playing an important role in the field of advanced materials because of their intriguing applications such as catalysis,[1] magnetism,[2] luminescence,[3] and so on. Simultaneously, MOFs have been of intense interest not only due to their diverse structural flexibility,[4] but also because of their superior and broad applications in many research fields such as optical devices,[5] gas storage,[6] adsorption,[7] magnetism,[8] and catalysis.[9] Recently, an increasing number of Ln MOFs which adopt doping lanthanide ions in MOFs have been well announced.[10] It appears that the luminescent intensity will be improved, the quantum efficiency will also be enhanced, because concentration quenching effect will be dispelled or decreased. The luminescent Ln MOFs show a great potential as fluorescent material because the rare-earth ions are of a very rich electronic energy level. Also, in these materials, the emission can be obtained by a fluorescence of the conjugate ligand, mainly by the use of lanthanides. The ex[a] Y. Liu, Y. Zhang, G. H. Hu, S. Zhou, Prof. Y. Xu State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing 210009 (P.R. China) E-mail: [email protected] [b] Prof. R. Fan, Y. Yang Department of Applied Chemistry Harbin Institute of Technology, Harbin 150001 (P.R. China) [c] Prof. Y. Xu State Key Laboratory of Coordination Chemistry Nanjing Tech University, Nanjing 210093 (P.R. China) Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/chem.201501193. Chem. Eur. J. 2015, 21, 10391 – 10399
group P212121, whereas compound 7 crystallizes in space group C2/c. Nevertheless, they all consist of new intertwined chains. Simultaneously, on the basis of the above-mentioned compounds, we have realized a rational design strategy to form the doped Ln MOFs [(EuxTb1¢x)(IN)2L] (x = 0.35 (8), x = 0.19 (9), x = 0.06 (10)) by utilizing TbIII as the second “rareearth metal”. Interestingly, the photoluminescence of [(EuxTb1¢x)(IN)2L] are not only adjustable by the ratios of Eu/ Tb, but also temperature or excitation wavelength.
citation can profit from “antenna effects”,[11] that is, the conjugate ligand is excited primarily, then transfer the energy to the luminescence centers. In addition, the guest solvent molecules can also conduce to the luminescence. In the previous literatures, a quantity of doped Ln MOFs have been reported.[12] It is not difficult to find that the Ln ions of most reported doped Ln MOFs are luminescent ions.[13] As we know, due to their red and green light emission, Eu3 + and Tb3 + become main ingredients for rare-earth trichromatic lamp with fluorescent powder. Recently, Cahill et al. reported the Tb3 + center sensitize the Eu3 + , effectively enhance Eu3 + emission in hetero-lanthanide coordination polymers.[14] Enhancement of Eu, while quenching of Tb emissions in [(Eu0.1:Tb99.9)2(2, 2-biphenate)3(H2O)2], has been reported by Williams et al.[15] In this paper, HIN is employed as ligand, choosing HIN as the ligand is based on the following considerations: 1) HIN is a pyridine-carboxylic acid, which is a heterocyclic acid with a conjugated structure and easily coordinated to metals to form compound; 2) The carboxylate group of HIN is able to provide diverse bonding modes to bridge adjacent LnIII ions; 3) As one type of polydentate ligand, the N and O atoms of HIN are locating in the opposite sites of the pyridine ring, which can make HIN act as an excellent linear ligand. In addition, the solvent (ethanediol) also act as a ligand, which compensates the charge and stabilizes the structure. Herein, we report seven new one-dimensional Ln MOFs, [Ln(IN)2L] (Ln = Eu (1), Tb (2), Er (3), Dy (4), Ho (5), Gd (6), La (7)) with two kinds of new helices. Then we successfully synthesized three doped Ln MOFs [(EuxTb1¢x)(IN)2L] (x = 0.35 (8), x = 0.19 (9), x = 0.06 (10)) by using TbIII as the second “rare-earth metal”. Lumines-
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Full Paper cent properties of the doped Ln MOFs were studied. Interestingly, the photoluminescence of [(EuxTb1¢x)(IN)2L] is not only adjustable by the ratios of Eu/Tb, but also through the temperature and excitation wavelengths.
Results and Discussion Synthesis Recently, the hydrothermal/solvothermal synthesis method has been a primary method in the synthesis of Ln MOFs. As we know, many factors can influence the growth of crystals, such as initial reactants, pH values, starting concentrations of reactants, solvents, reaction temperature, and time. In our case, solvent (ethanediol) plays an important role in the formation of compounds 1–10. It not only acts as the solvent, but also as a ligand, which can compensate the charge and establish a stable structure. The rod-like compounds 1–7 and the doped-lanthanide species 8–10 were prepared by rare-earth oxides, HIN, and HCOOH in ethanediol. Although HCOOH is not included in the final products, but we cannot obtain the above 10 compounds without HCOOH. The above compounds, including doped 8, 9, and 10, could be easily obtained under solvothermal synthesis and have good reproducibility.
Figure 1. a) View of the asymmetric unit of compound 1; b) Coordination mode of ErIII center.
Crystal structure Single crystal structural analyses reveal that compounds 1–6 and 8–10 crystallize in the orthorhombic, a chiral space group P2(1)2(1)2(1), they are isostructural, whereas compound 7 crystallizes in the monoclinic space group C2/c. Although formulas for ten compounds are very similar, the structures of compounds 1–6 and 8–10 are different to 7 due to the different symmetries. Thus here compounds 1 and 7 are described in detail as representations. As shown in Figure 1 a, the asymmetric unit of compound 1 consists of one crystallographically independent EuIII ion, two IN¢ ligands, and one L¢ anion. The EuIII ion is nine-coordinated by three oxygen atoms from two different L¢ ligands and six oxygen atoms from four different IN¢ligands to form a tricapped trigonal prism coordination geometry, in which the atoms O(1) and O(2) are located at the capping positions (Figure 1 b). The bond lengths of Eu¢O range from 2.305(2) to 2.873(4) æ, whereas the bond angles of O-Eu-O are between 47.83(11) and 151.28(8) 8. All the bond lengths and bond angles are in accordance to the reported literatures.[16] Scheme 1 a and b shows the coordination modes of IN¢ and L¢ ligands in compound 1: It clearly shows two kinds of ligands IN¢ and L¢ in compound 1; the former coordinate to two LnIII ions in a m2h2 :h3 mode and the latter is connected to two LnIII ions in a m2h1:h2 mode. Compared with our previously reported 1D chain-like [Er((IN))3(H2O)2]n, they have both utilized HIN as supporting ligand, but in this paper, ethanediol has been introduced as another ligand, which can establish a stable structure.[17] Adjacent EuIII ions are connected to each other by a L¢ ligand, and two IN¢ ligands to form an “airplane” conformation (Figure 2 a). Chem. Eur. J. 2015, 21, 10391 – 10399
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Scheme 1. Coordination modes of a) IN¢ and b) L¢ ligands in compound 1; c) Coordination modes of IN¢ in compound 3.
Then, on the basis of this “airplane” conformation, along the a axis, infinite chain is formed by the europium polyhedral, which is shown in Figure 2 b. Interestingly, a Eu-O-C chiral helical chain is found in 1, the symmetry of helical chain is a 21 screw axis, in which O5, O6, and their symmetric partners form bonds with europium atoms to generate a helical chain (Figure 3). The Flack parameter of 1 is 0.003(16), which indicates that the absolute configuration is correct. The chiral helices are particularly rare in Ln MOFs, with a notable example being a zinc phosphate of [{Zn2(HPO4)4}{Co(dien)2}]·H3O.[18] As showing in Figure S2 (the Supporting Information), the packing view of compound 1 displays a 3D supermolecular structure built up by 1D chains further linked by hydrogen bonds. Figure 4 shows the kind of hydrogen bonds in the network are O¢H···N, which is formed through oxygen atoms of
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Figure 4. The hydrogen bonds between IN¢ ligands and L¢ ligands in the adjacent chains of compound 1.
Figure 2. a) Coordination modes of the adjacent EuIII ions in compound 1; b) the infinite chain based on an “airplane” conformation.
L¢ ligands and nitrogen atoms of IN¢ ligands, respectively. The distances of O1¢H1···N2a (¢x, 0.5 + y, ¢0.5¢z) is 2.671(5) æ. The details of hydrogen bonds of 1–10 are given in Table S5 (the Supporting Information). When the Eu2O3 was replaced by La2O3, a similar La-MOF was obtained. Compared with compound 1, singlecrystal XRD reveals that compound 7 crystallizes in the orthorhombic, space group C2/c. As shown in Figure 5, the asymmetric unit of 7 is similar to compound 1. And in compound 7, IN¢ ligands are in a m2-h2 :h3 mode (Scheme 1 c). Along the b axis, the infinite chain which is similar to the one of compound 1 is formed by the lanthanum polyhedral (Figure S2, the Supporting Information). Because of different symmetry, the structure of compound 7 can described in another way, as show in Figure 6. The structure of framework for 3 is consists of both land d-helical La¢O chains, whereas the two types of ¢[La¢O]n¢ chains are fitted together to form a new intertwined La¢O double ¢[Ln¢O]n¢ helices by sharing the LaIII ions. Figure 3. l-Helical EuO-C chain of compound 1.
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Figure 5. View of the asymmetric unit of compound 7.
Powder X-ray diffraction The measured and simulated powder X-ray diffraction (PXRD) patterns of 1–10 are shown in Figure S5 (the Supporting Information). The measured XRD patterns are in agreement with the calculated patterns, which indicate the phase purity of compounds 1–10. The difference in reflection intensities during collection of the experimental XRD data are probably due to the preferred orientation effect of the powder. IR spectrum The IR spectra of 1–10 are presented in Figure S6 (the Supporting Information). It is easy to notice that the IR spectra of 1–10 are analogous, and thus here we give a detailed analysis of compound 1. In the IR spectrum of compound 1, absorption between 568 and 767 cm¢1 correspond to the n (Eu¢O) vibra-
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Figure 6. a) l-Helical La¢O chain, b) d-Helical La¢O chain of compound 7.
tions. The characteristic bands for the pyridine ring are in the region of 1218–1585 cm¢1. A peak at 3383 cm¢1 can be ascribed to the stretching vibration of O¢H, whereas the peaks in the range of 1012–1093 cm¢1 correspond to the n (C¢O) vibrations; these peaks can demonstrate the presence of hydroxyl groups of ethanediol. The features are in accord with the reported compounds.[19]
Luminescence properties Due to the excellent luminescent properties of EuIII, TbIII and HIN, compounds 1–3 and 8–10 were investigated. The photoluminescence spectra are shown in Figures 7 and 8 for compounds 1–3 and 8–10, respectively. The solid state emission spectrum of compound 1 at room temperature was measured under excitation at 394 nm. The emission spectrum exhibits the characteristic transition of EuIII ion. Compound 1 shows five emission bands at 579, 589, 612, 655, and 702 nm, which can be assigned to 5D0 !7FJ (J = 0, 1, 2, 3, 4) with the 5D0 !7F2 emission as the dominant band. Only one emission line can be observed for the non-degenerated 5 D0 !7F0 transition, which in agreement with the having of one site of symmetry (Cs, Cn, or Cnv) for the europium within the compound. The 5D0 !7F1 transition is a parity-allowed magnetic dipole transition, which is almost independent of the host material and its intensity should vary with the crystal field strength acting on the EuIII ion. The 5D0 !7F2 transition is an electric dipole transition and intensively varies with the site symmetry of EuIII ions. The absence of the IN¢ ligand emission in the fluorescence spectra indicates an efficient energy transfer from the IN¢ ligands to the lanthanide centers, which can enhance the fluorescence efficiency, but also effectively reduces the loss of energy by radiationless thermal vibrations Chem. Eur. J. 2015, 21, 10391 – 10399
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Figure 7. Emission spectra of compounds 1–3.
and increases the rigidity of molecule. The above luminescent property is in agreement with the reported EuIII compounds.[20] The luminescent property of compound 2 was observed in the solid state at room temperature upon excitation at
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Figure 8. Excitation and emission spectra of compounds 8–10.
367 nm. The emission spectrum exhibits the characteristic transition of TbIII ion. Compound 2 shows four emission bands at 489, 546, 589, and 621 nm arising from the 5D4 !7FJ (J = 6, 5, 4, 3) with the 5D4 !7F5 emission as the dominant band, which is in agreement with those reported TbIII compounds.[21] Similar Chem. Eur. J. 2015, 21, 10391 – 10399
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to compound 1, there is also no emission arising from the IN¢ ligand. The solid-state emission spectrum of pure compound 3 at room temperature is measured under excitation at 338 nm. The maximum emission peaks at 379 and 403 nm among the emission bands in a range of 375–450 nm are ascribed to the coordinated IN¢ ligand, which displays a very weak emission at 431 nm corresponding to that caused by the exciting light at 330 nm. Compound 3 has a split peak due to the low symmetry of IN¢ ligands. The enhanced fluorescence efficiency of compound 3 can be attributed to the coordination of IN¢ and L¢ ligand to ErIII. The solid-state emission spectrum of pure compound 8 at room temperature is measured under excitation at 395 nm. The emission spectrum exhibits the characteristic transition of EuIII ion. Compound 8 also shows five emission bands at 579, 589, 612, 656, and 702 nm that can be assigned to 5D0 !7FJ (J = 0, 1, 2, 3, 4) with the 5D0 !7F2 emission as the dominant band. It is very similar to compound 1. In the emission spectrum, compound 8 displays the typical EuIII emission peaks, no emission bands for TbIII, and the ligand in the compound are observed. This indicates that the enhanced fluorescence intensity is due to the probability of the energy transfer from TbIII ion to EuIII ion and the coordination of IN¢ ligand to the LnIII ion. The solid-state emission spectrum of pure compound 9 at room temperature is measured at 378 nm. It shows six emission bands at 488, 547, 589, 613, 656, and 702 nm that can be assigned to 5D4 !7FJ (J = 6, 5, 4) and 5D0 !7FJ (J = 1, 2, 3, 4) with the 5D0 !7F2 emission as the dominant band. The emission band at 589 nm can not only be assigned to 5D4 !7F4 (J = 6, 5, 4), but also can be assigned to 5D0 !7F1 and the photoluminescence spectra of compound 9 not only exhibit the characteristic transition of EuIII ion, but also TbIII ion. In the emission spectrum, compound 9 displays the typical EuIII and TbIII emission peaks, no emission bands for the ligand in the compound are observed; this result clearly indicates that the HIN is an excellent antenna chromophore for sensitizing both the EuIII ion and the TbIII ion.[22] The solid-state emission spectrum of pure compound 10 at room temperature is measured under excitation at 370 nm. It shows four strong emission bands at 489, 545, 588, and 621 nm that can be assigned to 5D4 !7FJ (J = 6, 5, 4, 3), with the 5D4 !7F5 emission as the dominant band, which correspond to the characteristic transitions of TbIII and are very similar to compound 2. In the emission spectrum, compound 10 displays the typical TbIII emission peaks, no emission bands for EuIII, and the ligand in the compound is observed due to the fluorescence quenching when EuIII concentration is 2.23 %. So the enhanced fluorescence intensity is due to the energy transferred to Tb from IN¢ ligands. Compared with [Tb0.957Eu0.043(H2cpda)(Hcpda)(H2O)]·6 H2O (H3cpda: 5-(4-carboxyphenyl)-2,6-pyridinedicarboxylic acid) with adjustable photoluminescence reported by Cui et al.,[23] the formula [(EuxTb1¢x)(IN)2L] reported in this paper can readily generate tunable photoluminescence properties by changing EuIII/TbIII ratios. In addition, because Eu3 + and Tb3 + within the
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Full Paper sample emit different colors of red at 612 nm and green at 545 nm, respectively, the luminescence colors of [(EuxTb1¢x)(IN)2L] can also readily generate tunable colors from red to yellow, and green. The temperature-dependence of the emission spectrum of compounds 8–10 are investigated at 77 and 293 K in Figure 9. The luminescent intensity of both Tb3 + and Eu3 + in 8 and 9 increases as the temperature increases, which is due to the thermal activation of nonradiative-decay pathways.[23] Interestingly, compound 10 exhibits a significantly different luminescent behavior compared to those of 8 and 9. The emission intensity of the Tb3 + strongly decreases, whereas that of the Eu3 + emission increases as the temperature increases in 10. The temperaturedependent decreases of the Tb3 + emission could be attributed to the thermally driven phonon-assisted Fçrster transfer mechanism from the Tb3 + to Eu3 + ions. The solid state emission spectra of compound 10 are investigated under excitation at 295 and 370 nm at room temperature, respectively. In Figure 10, the emission spectrum exhibits the characteristic transition of EuIII ion and the luminescence color of compound 10 shows red under excitation at 295 nm, whereas the emission spectrum exhibits the characteristic transition of the TbIII ion and luminescence colors of compound 10 shows green under excitation at 370 nm. Because of the interesting phenomena, we chose the excitation at 295 nm to investigate the temperature-dependence of the emission spectrum. The dynamics of the Eu3 + and Tb3 + PL were measured at room temperature (Figure 11). All the lifetimes were successfully fitted by ways of a single exponential law (square correlation factor R2 > 0.99). From the decay curve of 5D0 !7F2 from Eu3 + in 1 under 295 nm excitation, the decay lifetime was determined to be 0.7117 ms; From the decay curve of 5D4 !7F5 from Tb3 + in 2 under 295 nm excitation, the decay lifetime was determined to be 1.3426 ms; From the decay curve of 5D0 !7F2 from Eu3 + in 8 under 295 nm excitation, the decay lifetime was determined to be 0.9969 ms; From the decay curve of 5 D0 !7F2 from Eu3 + in 9 under 300 nm excitation, the decay lifetime was determined to be 1.0275 ms; From the decay curve of 5D4 !7F5 from Tb3 + in 10 under 295 nm excitation, the decay lifetime was determined to be 1.1268 ms. From the above, along with the decrease of EuIII concentration, the time decay varies from 0.7117 ms in samples up to 1.3426 ms in the samples with the largest Tb concentrations.
Conclusion We have successfully synthesized seven new one-dimensional Ln MOFs and three doped EuIII/TbIII MOFs by using the solvothermal synthesis method. Under the same conditions, we have obtained two types of structures with different new helices. The frameworks of compounds 1–6 and 8–10 consist of one type of helical Ln¢O¢C chain; whereas in the structure of compound 7, l-and d-helical Ln¢O chains are observed. The luminescent investigation indicates that compounds 1–3 and 8–10 are excellent candidates for fluorescent materials, and the formula [(EuxTb1¢x)(IN)2L] can readily generate tunable phoChem. Eur. J. 2015, 21, 10391 – 10399
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Figure 9. Emission spectra of 8–10 recorded at 77 and 293 K excited at 296 nm.
toluminescence properties by changing the EuIII/TbIII ratios. This study can be applied to generate tunable luminescent properties in the visible region by selecting the appropriate ratios of doped luminescent lanthanide ions and metal–organic host materials. The temperature-dependence of the emission
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Full Paper Experimental Section Materials and methods All chemicals were of reagent grade and without further purification. The crystalline products were characterized by powder XRD, IR spectrum, and fluorescence spectrum. The elemental analysis (C, H, and N) were obtained using a PerkinElmer 2400 elemental analyzer. Powder X-ray diffraction data were performed on a Bruker D8 Advance diffractometer with CuKa radiation (l = 1.54056 æ), with a step speed of 0.1 8 per second. The infrared spectra were measured on a Nicolet Impact 410 Fourier transform IR (FTIR) spectrometer by using the pressed KBr pellet technique from 4000 to 450 cm¢1. The solid-state emission/excitation spectra were recorded on an FP-6500 spectrofluorimeter with a 450 W xenon lamp as the excitation source.
Syntheses
Figure 10. Solid state emission spectrum of compound 10 under excitation at 295 and 370 nm, respectively, at room temperature.
Synthesis of 1: A mixture of Eu2O3 (0.1936 g, 0.35 mmol) and ethanediol (8 mL) was stirred for 12 h at room temperature, then the mixture was transferred to a 25 mL Teflon reactor and heated under autogenous pressure at 170 8C for 7 days. After cooling to room temperature, colorless rod-like crystals were filtered off, washed with ethyl alcohol, and dried at room temperature for 24 h (yield 57 % based on Eu). IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (s), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for EuC14N2O6H13 : C 36.74, H 2.84, N 6.12; found: C 36.67, H 2.75, N 6.02.
Figure 11. Decay curves of compounds 1, 2, and 8–10.
spectrum of compound 10 exhibits a significantly different luminescent behavior that the emission intensity of the Tb3 + strongly decreases, whereas that of the Eu3 + emission increases as the temperature increases, which provides thoughts for designing various Ln MOFs for practically useful luminescent thermometers. Interestingly, luminescent properties of 10 are not only adjustable by temperature, but also excitation wavelength.
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Synthesis of 2: Compound 2 was prepared in a procedure similar to that of 1, except that Tb4O7 was utilized instead of Eu2O3 ; rodlike crystals were obtained. Yield: 47 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for TbC14N2O6H13 : C 36.19, H 2.80, N 6.03; found: C 36.25, H 2.76, N 5.97. Synthesis of 3: Compound 3 was prepared in a procedure similar to that of 1, except that Er2O3 was utilized instead of Eu2O3 ; pink rod-like crystals were obtained. Yield: 44 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for ErC14N2O6H13 : C 35.56, H 2.75, N 5.92; found: C 35.43, H 2.69, N 5.84. Synthesis of 4: Compound 4 was prepared in a procedure similar to that of 1, except that Dy2O3 was utilized instead of Eu2O3. Yield: 53 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for DyC14N2O6H13 : C 35.92, H 2.78, N 5.98; found: C 35.80, H 2.72, N 5.93. Synthesis of 5: Compound 5 was prepared in a procedure similar to that of 1, except that Ho2O3 was utilized instead of Eu2O3. Yield: 51 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for HoC14N2O6H13 : C 35.73, H 2.76, N 5.96; found: C 35.63, H 2.65, N 5.88. Synthesis of 6: Compound 6 was prepared in a procedure similar to that of 1, except that Gd2O3 was utilized instead of Eu2O3. Yield: 47 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs),
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Full Paper 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for GdC14N2O6H13 : C 36.32, H 2.81, N 6.05; found: C 36.17, H 2.77, N 6.11. Synthesis of 7: Compound 7 was prepared in a procedure similar to that of 1, except that La2O3 was utilized instead of Eu2O3. Yield: 54 %; IR (KBr): ~ n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for LaC14N2O6H13 : C 37.82, H 2.93, N 6.30; found: C 37.74, H 2.90, N 6.21.
least-squares technique on F2 with the use of the SHELX-2014/7 crystallographic software package. An empirical absorption correction was applied. The hydrogen atoms for CH2 and CH were located in calculated positions, whereas the H atom for OH was located from different map. All H atoms were assigned isotropic displacement parameters, whereas all the non-hydrogen atoms were refined anisotropically. The Ln occupancy factors of compounds 8-10 are fixed by Eu/Tb ratios of 0.35/0.65, 0.19/0.81 and 0.06/0.94, respectively, which are confirmed by energy-dispersive X-ray (EDX) analysis results as shown in Tables S1–S3 (the Supporting Information). Eu/Tb occupied one metal position was refined with the same coordinates and anisotropic thermal parameters.
Synthesis of 8: Compound 8 was prepared in a procedure similar to that of 1, except that using the doped Eu2O3 and Tb4O7 which the ratio of Eu2O3/Tb4O7 was 3:7 was utilized instead of Eu2O3. CCDC-1055231 (1), CCDC-1055232 (2), CCDC-1055233 (3), CCDCYield: 42 IR (KBr): ~ n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 1055234 (4), CCDC-1055235 (5), CCDC-1055236 (6), CCDC-1055237 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (7), CCDC-1055238 (8), CCDC-1055239 (9), and CCDC-1055240 (10) (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemencontain the supplementary crystallographic data for this paper. tal analysis calcd (%) for Eu0.35Tb0.65C14N2O6H13 : C 36.38, H 2.82, N These data can be obtained free of charge from The Cambridge 6.06; found: C 36.31, H 2.74, N 5.98. Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_reSynthesis of 9: Compound 9 was prepared in a procedure similar quest/cif. The crystallographic data and structure determination of to that of 8, except that the ratio of Eu2O3/Tb4O7 was 1:19. Yield: compounds 1–10 are summarized in Table 1. The selected bond 47 %; IR (KBr): ~ n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 Table 1. Crystal data and structure refinements for 1–10. (w), 1012 (w), 890 (w), 882 (w), 1 2 3 4 5 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental DyC14N2O6H13 HoC14N2O6H13 Formula EuC14N2O6H13 TbC14N2O6H13 ErC14N2O6H13 analysis calcd (%) for Mw 457.22 464.18 472.52 467.76 470.19 cryst. syst. orthorhombic orthorhombic orthorhombic orthorhombic orthorhombic Eu0.19Tb0.81C14N2O6H13 : C 36.30, H space group P2(1)2(1)2(1) P2(1)2(1)2(1) P2(1)2(1)2(1) P2(1)2(1)2(1) P2(1)2(1)2(1) 2.81, N 6.05; found: C 36.25, H a [æ] 7.1983(7) 7.2088(13) 7.1894(6) 7.1976(6) 7.2037(13) 2.80, N 5.99. Synthesis of 10: Compound 10 was prepared in a procedure similar to that of 8, except that the ratio of Eu2O3/Tb4O7 was 1:66. Yield: 50 %; IR (KBr): ~n = 3383 (b), 1585 (vs), 1538 (vs), 1498 (m), 1412 (vs), 1350 (w), 1093 (s), 1062 (w), 1047 (w), 1012 (w), 890 (w), 882 (w), 862 (m), 767 (s), 712 (m), 695 (s), 681 (s), 568 cm¢1 (w); elemental analysis calcd (%) for Eu0.06Tb0.94C14N2O6H13 : C 36.22, H 2.80, N 6.04; found: C 36.04, H 2.74, N 5.97.
Single-crystal X-ray structure determination Single crystals of compounds 1– 10 were carefully selected under the microscope and mounted onto the tip of a thin glass fiber with epoxy glue for data collection. The collection of single-crystal X-ray analyses data were carried out on a Bruker Apex 2 CCD with graphite-monochromated MoKa radiation (l = 0.071073 æ) at 296(2) K using the w-2q scan method. The crystal structures were confirmed by direct methods and refined by full-matrix Chem. Eur. J. 2015, 21, 10391 – 10399
b [æ] c [æ] a [8] b [8] g [8] V [æ3] T [K] Z Rint data collected unique data GOF on F2 R1[a] [I > 2s(I)] wR2[b] (all data)
13.5912(13) 15.5938(14) 90 90 90 1525.6(2) 296(2) 4 0.0330 11 339 2928 1.020 0.0215 0.0462 6 formula GdC14N2O6H13 Mw 462.51 cryst. syst. orthorhombic space group P2(1)2(1)2(1) a [æ] 7.215(4) b [æ] 13.570(8) c [æ] 15.616(9) a [8] 90 b [8] 90 g [8] 90 V [æ3] 1528.8(15) T [K] 296(2) Z 4 Rint 0.0581 data collected 11 335 unique data 2949 GOF on F2 0.992 R1[a] [I > 2s(I)] 0.0279 wR2[b] (all data) 0.0515
13.542(3) 15.616(3) 90 90 90 1524.5(5) 296(2) 4 0.0250 11 298 2873 1.059 0.0208 0.0495 7 LaC14N2O6H13 444.17 orthorhombic C2/c 21.491(5) 7.4138(16) 20.282(4) 90 99.144(2) 90 3190.5(12) 296(2) 8 0.0373 11 378 3045 1.029 0.0250 0.0581
13.4890(11) 15.5931(13) 90 90 90 1512.2(2) 296(2) 4 0.0239 9891 2873 1.030 0.0153 0.0309 8 Eu0.35Tb0.65C14N2O6H13 461.75 orthorhombic P2(1)2(1)2(1) 7.2049(5) 13.5517(10) 15.6072(11) 90 90 90 1523.87(19) 296(2) 4 0.0203 11 290 2927 1.005 0.0138 0.0311
13.5132(11) 15.6057(12) 90 90 90 1517.9(2) 296(2) 4 0.0310 11 227 2926 1.000 0.0162 0.0368 9 Eu0.19Tb0.81C14N2O6H13 462.86 orthorhombic P2(1)2(1)2(1) 7.2026(6) 13.5416(11) 15.6011(12) 90 90 90 1521.6(2) 296(2) 4 0.0476 11 328 2908 1.042 0.0227 0.0438
13.510(2) 15.604(3) 90 90 90 1518.6(5) 296(2) 4 0.0531 11 061 2929 1.148 0.0369 0.0851 10 Eu0.06Tb0.94C14N2O6H13 463.77 orthorhombic P2(1)2(1)2(1) 7.2045(13) 13.534(2) 15.600(3) 90 90 90 1521.1(5) 296(2) 4 0.0248 11 290 2927 1.026 0.0160 0.0347
[a] R1 = S j j Fo j ¢ j Fc j j /S j Fo j . [b] wR2 = S[w(Fo2¢Fc2)2]/S[w(Fo2)2]1/2.
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Full Paper lengths and angles for 1–10 are listed in Table S4 (the Supporting Information).
Acknowledgements
[10]
We thank the NSFC (Grant 21171044 and 21371040), Natural Science Foundation of Jiangsu Province, China (Grant BK2012823), Graduate Education Innovation Project (KYLX_ 0740) and the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions. Keywords: helical structures · luminescence · metal–organic frameworks · lanthanides · X-ray diffraction [1] a) M. Shibasaki, N. Yoshikawa, Chem. Rev. 2002, 102, 2187; b) S. Jujjuri, E. Ding, S. G. Shore, M. A. Keane, Appl. Organomet. Chem. 2003, 17, 493; c) J. Inanaga, H. Furuno, T. Hayano, Chem. Rev. 2002, 102, 2211; d) J. S. Seo, D. Whang, H. Lee, S. I. Jun, J. Oh, Y. J. Jeon, K. Kim, Nature 2000, 404, 982. [2] a) S. Mukherjee, Y. H. Lan, G. E. Kostakis, R. Cl¦rac, C. E. Anson, A. K. Powell, Cryst. Growth Des. 2009, 9, 577; b) A. J. Tasiopoulos, T. A. O’Brien, K. A. Abbound, G. Christou, Angew. Chem. Int. Ed. 2004, 43, 345; Angew. Chem. 2004, 116, 349. [3] Y. Qiu, H. Liu, Y. Ling, H. Deng, R. Zeng, G. Zhou, M. Zeller, Inorg. Chem. Commun. 2007, 10, 1399. [4] a) M. Sakamoto, K. Manseki, H. Okawa, Coord. Chem. Rev. 2001, 219, 379; b) J. J. Perry Iv, J. A. Perman, M. J. Zaworotko, Chem. Soc. Rev. 2009, 38, 1400; c) J. Cheng, J. Zhang, S. Zheng, M. Zhang, G. Yang, Angew. Chem. Int. Ed. 2006, 45, 73; Angew. Chem. 2006, 118, 79; d) H. Furukawa, K. E. Cordova, M. O’Keeffe, O. M. Yaghi, Science 2013, 341, 1230444; e) T. R. Cook, Y. R. Zheng, P. J. Stang, Chem. Rev. 2013, 113, 734; f) M. O’Keeffe, O. M. Yaghi, Chem. Rev. 2012, 112, 675; g) M. Li, D. Li, M. O’Keeffe, O. M. Yaghi, Chem. Rev. 2014, 114, 1343. [5] a) B. Moulton, M. Zaworotko, Chem. Rev. 2001, 101, 1629; b) D. Braga, F. Grepioni, GR. Desiraju, Chem. Rev. 1998, 98, 1375; c) W. Zhang, R. G. Xiong, Chem. Rev. 2012, 112, 1163; d) O. Kahn, Acc. Chem. Res. 2000, 33, 647; e) D. F. Sava, L. E. S. Rohwer, M. A. Rodriguez, T. M. Nenoff, J. Am. Chem. Soc. 2012, 134, 3983; f) C. Wang, T. Zhang, W. Lin, Chem. Rev. 2012, 112, 1084; g) C. Y. Sun, X. L. Wang, X. Zhang, C. Qin, P. Li, Z. M. Su, D. X. Zhu, G. G. Shan, K. Z. Shao, H. Wu, J. Li, Nat. Commun. 2013, 4, 2717. [6] Q. R. Fang, G. S. Zhu, M. Xue, J. Y. Sun, Y. Wei, S. L. Qiu, R. R. Xu, Angew. Chem. Int. Ed. 2005, 44, 3845; Angew. Chem. 2005, 117, 3913. [7] a) X. Zhao, B. Zhao, Y. Ma, W. Shi, P. Cheng, Z. Jiang, D. Liao, S. Yan, Inorg. Chem. 2007, 46, 5832; b) B. Zhao, P. Cheng, Y. Dai, C. Cheng, D. Liao, S. Yan, Z. Jiang, G. Wang, Angew. Chem. Int. Ed. 2003, 42, 934; Angew. Chem. 2003, 115, 964. [8] a) H. Li, M. Eddaoudi, M. O’Keeffe, O. M. Yaghi, Nature 1999, 402, 276; b) O. M. Yaghi, H. Li, C. Davis, D. Richardson, T. L. Groy, Acc. Chem. Res. 1998, 31, 474. [9] a) W. Lin, O. R. Evans, R. Xiong, Z. Wang, J. Am. Chem. Soc. 1998, 120, 13272; b) J. Lee, O. K. Farha, J. Roberts, K. A. Scheidt, S. T. Nguyen, J. T. Hupp, Chem. Soc. Rev. 2009, 38, 1450; c) H. R. Moon, D. W. Lim, M. P.
Chem. Eur. J. 2015, 21, 10391 – 10399
www.chemeurj.org
[11]
[12]
[13]
[14] [15] [16]
[17] [18] [19]
[20]
[21]
[22] [23]
Suh, Chem. Soc. Rev. 2013, 42, 1807; d) M. Yoon, R. Srirambalaji, K. Kim, Chem. Rev. 2012, 112, 1196; e) L. Ma, C. Abney, W. Lin, Chem. Soc. Rev. 2009, 38, 1248; f) J. Zhang, A. V. Biradar, S. Pramanik, T. J. Emge, T. Asefa, J. Li, Chem. Commun. 2012, 48, 6541. a) B. Q. Ma, D. S. Zhang, S. Gao, Angew. Chem. Int. Ed. 2000, 39, 3644; Angew. Chem. 2000, 112, 3790; b) M. B. Zhang, S. T. Zheng, G. Y. Yang, Chin. J. Struct. Chem. 2005, 7, 816; c) X. J. Zhang, Y. H. Xing, Cryst. Growth Des. 2007, 7, 2041; d) Z. B. Han, X. N. Z. Cheng, Z. Anorg. Allg. Chem. 2005, 631, 937; e) L. Ma, O. R. Evans, B. M. Foxman, W. B. Lin, Inorg. Chem. 1999, 38, 5837; f) B. Yan, Q. Y. Xie, Inorg. Chem. Commun. 2003, 6, 1448; g) H. L. Gao, P. Cheng, Chin. J. Inorg. Chem. 2004, 20, 1145. a) J. M. Lehn, Angew. Chem. Int. Ed. Engl. 1990, 29, 1304; Angew. Chem. 1990, 102, 1347; b) Y. Zhang, L. Huang, H. Miao, H. Wan, H. Mei, Y. Liu, Y. Xu, Chem. Eur. J. 2015, 21, 3234. a) M. L. Ma, C. Ji, S. Q. Zang, Dalton Trans. 2013, 42, 10579; b) X. T. Rao, Q. Huang, X. L. Yang, Y. J. Cui, Y. Yang, C. D. Wu, B. L. Chen, G. D. Qian, J. Mater. Chem. 2012, 22, 3210; c) H. L. Guo, Y. Z. Zhu, S. L. Qiu, J. A. Lercher, H. J. Zhang, Adv. Mater. 2010, 22, 4190. a) Q. Tang, S. X. Liu, Y. W. Liu, D. F He, J. Miao, X.-Q. Wang, Y.-J. Ji, Z. P. Zheng, Inorg. Chem. 2014, 53, 289; b) Y. Zhang, L. Chen, W. W. Ju, Y. XU, Chem. Res. Chin. Univ. 2014, 30, 194; c) Y. Zhang, W. W. Ju, X. Xu, Y. Lv, D. R. Zhu, Y. XU, Cryst. Eng. Comm. 2014, 16, 5681. D. T. de Lill, A. de Bettencourt-Dias, C. L. Cahill, Inorg. Chem. 2007, 46, 3960. C. L. Choi, Y. F. Yen, H. H. Y. Sung, A. W. H. Siu, S. T. Jayarathne, K. S. Wong, I. D. Williams, J. Mater. Chem. 2011, 21, 8547. a) L. Chen, J. Y. Guo, X. Xu, W. W. Ju, D. Zhang, D. R. Zhu, Y. Xu, Chem. Commun. 2013, 49, 9728; b) D. W. Yan, L. Zheng, Z. B. Zhang, D. R. Zhu, Y. Xu, J. Coord. Chem. 2010, 63, 4215. L. J. Han, X. C. Sun, Y. L. Zhu, W. L. Zhou, Q. Chen, Y. Xu, J. Chem. Crystallogr. 2010, 40, 579. Y. Wang, J. H. Yu, M. Guo, R. R. Xu, Angew. Chem. Int. Ed. 2003, 42, 4089; Angew. Chem. 2003, 115, 4223. a) L. Zheng, Y. Xu, X. L. Zhang, Z. B. Zhang, D. R. Zhu, S. Chena, S. P. Elangovan, Cryst. Eng. Comm. 2010, 12, 694; b) W. W. Ju, D. Zhang, D. R. Zhu, Y. Xu, Inorg. Chem. 2012, 51, 13373; c) Y. Xu, S. Ding, X. J. Zheng, Solid. State. Chem. 2007, 180, 2020; d) W. Zhou, L. Chen, Y. Xu, Z. Anorg. Allg. Chem. 2013, 639, 947. a) C. Daiguebonne, N. Kerbellec, Y. G¦rault, O. J. Guillou, J. Alloys Compd. 2008, 451, 372; b) L. Zheng, X. M. Qiu, Z. B. Zhang, D. R. Zhu, Y. Xu, Inorg. Chem. Commun. 2011, 14, 906; c) Y. Zhu, X. Sun, D. R. Zhu, Y. Xu, Inorg. Chim. Acta 2009, 362, 2565. a) W. L. Zhou, Y. Xu, L. J. Han, D. R. Zhu, Dalton Trans. 2010, 39, 3681; b) H. Xu, X. Li, D. Yan, Inorg. Chem. Commun. 2008, 11, 1187; c) P. Mahata, K. V. Ramya, S. Natarajan, Dalton Trans. 2007, 4017; d) L. Zheng, X. M. Qiu, Y. Xu, J. Fu, Y. Yuan, D. R. Zhu, S. Chen, Cryst. Eng. Comm. 2011, 13, 2714. Y. J. Cui, H. Xu, Y. F. Yue, Z. Y. Guo, J. C. Yu, Z. X. Chen, J. K. Gao, Y. Yang, G. D. Qian, B. L. Chen, J. Am. Chem. Soc. 2012, 134, 3979. Y. J. Cui, W. F Zou, R. J. Song, J. C. Yu, W. Q. Zhang, Y. Yang, G. D. Qian, Chem. Commun. 2014, 50, 719.
Received: March 26, 2015 Published online on June 3, 2015
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