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Three Metal-Organic Frameworks Based on Binodal Inorganic Building Units and Hetero-O, N Donor Ligand: Solvothermal Syntheses, Structures, and Gas Sorption Properties Xiaolong Luo, Libo Sun, Jun Zhao, Dong-Sheng Li, Dongmei Wang, Guanghua Li, Qisheng Huo, and Yunling Liu Cryst. Growth Des., Just Accepted Manuscript • DOI: 10.1021/acs.cgd.5b00791 • Publication Date (Web): 14 Sep 2015 Downloaded from http://pubs.acs.org on September 20, 2015
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Three Metal-Organic Frameworks Based on Binodal Inorganic Building Units and Hetero-O, N Donor Ligand: Solvothermal Syntheses, Structures, and Gas Sorption Properties Xiaolong Luo,a Libo Sun,a Jun Zhao,b Dong-Sheng Li,*,b Dongmei Wang,a Guanghua Li,a Qisheng Huoa and Yunling Liu*,a a
State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry,
Jilin University, Changchun 130012, P. R. China b
College of Mechanical & Material Engineering, Research Institute of Materials, China Three
Gorges University, Yichang 443002, China
*To whom correspondence should be addressed. Professor Yunling Liu College of Chemistry Jilin University Changchun 130012, P. R. China Fax: +86-431-85168624 E-mail:
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ABSTRACT Three new metal-organic frameworks (MOFs) based on hetero-O, N donor ligands, (Cu4I4)[Cu2(PDC)2DMF2]2•2DMF•H2O
(JLU-Liu15),
(Cu4I4)[Cu3(CPNA)3(Dabco)0.5DMF3]•4DMF•4H2O (Cu4I4)[Cu3(CPNA)3(H2O)0.5DMF3]•4DMF•4H2O
(JLU-Liu16) (JLU-Liu17),
(H2PDC
and =
pyridine-3,5-
dicarboxylic acid, H2CPNA = 5-(4’-carboxylphenyl) nicotinic acid, Dabco = 1,4Diazabicyclo[2.2.2]octane), have been solvothermal synthesized and structurally characterized by single-crystal X-ray diffraction analyses. JLU-Liu15 features a (3,4,4)-c sqc5588 net, while JLU-Liu16 and JLU-Liu17 are isostructural and possess new (3,4,4)-c topology. All of these compounds are composed of the binodal inorganic Cu2(CO2)4 paddle wheel and Cu4I4 cluster secondary building units (SBUs). It is worthy to note that the linkage between two nearby Cu4I4 clusters in JLU-Liu16 is µ2-Dabco, which changed to µ2-water molecule in JLU-Liu17. Furthermore, JLU-Liu15 exhibits high CO2 adsorption behaviours as well as I2 uptake and release feature.
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INTRODUCTION Over the past decades, the rational design and synthesis of metal-organic frameworks (MOFs) have attracted great attention as functional materials due to their structural novelties and potential applications (gas adsorption, catalysis, luminescent, sensing and magnetism etc.).1-3 Design and synthesis of the crystalline materials with novel topologies and desired functions is still a great challenge.4-7 To construct MOFs with novel structures can be considered from two aspects, ligand and metal. The ligands containing multidentate O and/or N donor often participate in the construction of diverse MOFs,8-14 and the various metals can effectively facilitate the formation of secondary building units (SBUs), such as M2(CO2)4,15 M3O(CO2)6,16 M4O(CO2)61, M6(µ3-O)4(µ3-OH)4(CO2)12,17 MxXyLz (X = Cl, Br or I; L = N, S or P ).18 Heterofunctional ligands can be easier to coordinate with numerous metal centres to form various types of SBUs. Recently, O’Keeffe and coworkers illustrated topological analysis of MOFs with polytopic linkers and/or multiple SBUs.6 In another aspect, copper(I) halides with the formula CuxXyLz have attracted particular attention,18 which can possess diverse geometrical configurations.19-24 However, most of the reported compounds with copper(I) halides SBUs possess 0D,25-26 1D27-28 and 2D29-30 structures, only a few 3D frameworks exhibited adsorption, catalysis, photochemical and photophysical properties.31-38 As mentioned above, many of the MOF structures are composed of one type of SBUs. It seems that the combination of general SBUs with copper(I) halides to form the multiple SBU MOFs can lead to plenty of structures with diverse topologies. In recent years, iodine is one of necessary microelements for human bodies, but radioactive iodine is harmful to humans and enriched in nuclear energy arena. Recently, the
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release and adsorption behavior of iodine have attracted increasing attention, and MOFs are good candidates for the capture of I2. One of famous MOFs, HKUST-1 has been applied to iodine sorption phenomena, because of an open-pored MOF containing coordinatively unsaturated metal centers.39 We have been engaged in developing new MOFs structures these years and pursued their potential applications in gas adsorption/separation, sensing and so on.40-45 As a continuation of our previous work, herein, we utilized the ternary SBUs strategy to construct MOFs with two different kinds of inorganic SBUs (the classic Cu2(CO2)4 paddle wheel and Cu4I4 cluster). Most of the MOFs constructed with Cu4I4 clusters are not robust enough to investigate the gas adsorption property except COZ-1 and Inof-8.35,46 The Cu2(CO2)4 paddle wheel and Cu4I4 cluster SBUs based MOFs are conducive to improve the stability of the structures and develop the gas adsorption property. Considering that the ligands may have great influence on the SBUs finally obtained, the hetero-O, N ligands pyridine-3,5-dicarboxylic acid (H2PDC) and 5-(4’carboxylphenyl) nicotinic acid (H2CPNA) are employed (scheme 1), in which the carboxylate group favored the formation of Cu2(CO2)4 paddle wheel units, while the pyridine facilitate the generation of Cu4I4 clusters. As expected, three novel MOFs based on a ternary SBUs including classical Cu2(CO2)4 paddle-wheel unit, Cu4I4 tetramer unit and organic SBU have been successfully
constructed,
namely
(Cu4I4)[Cu2(PDC)2DMF2]2•2DMF•H2O
(Cu4I4)[Cu3(CPNA)3(Dabco)0.5DMF3]•4DMF•4H2O (Cu4I4)[Cu3(CPNA)3(H2O)0.5DMF3]•4DMF•4H2O
(JLU-Liu16) (JLU-Liu17),
(H2PDC
(JLU-Liu15), and
=
pyridine-3,5-
dicarboxylic acid, H2CPNA = 5-(4’-carboxylphenyl) nicotinic acid, Dabco = 1,4Diazabicyclo[2.2.2]octane). Among these compounds, JLU-Liu15 exhibits the (3,4,4)-c sqc5588 net, while JLU-Liu16 and JLU-Liu17 are isostructural and both have the new topology with
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(3,4,4)-c net. Unfortunately, only compound JLU-Liu15 is stable after the removal of the guest molecules, and it exhibits high CO2 adsorption behaviour as well as I2 uptake and release feature. Compounds JLU-Liu16 and JLU-Liu 17 are not stable in air or other organic solvents, when we try to remove the guest molecular, the frameworks are collapsed.
EXPERIMENTAL SECTION Materials and physical characterizations The related chemicals and reagents were purchased from commercial sources and used without further purification. Infrared spectra were recorded on a Bruker IFS-66v/S FTIR spectrometer in the range of 400-4000 cm-1 using the KBr pallet. Powder X-ray diffraction (PXRD) data were collected on a Rigaku D-Max 2550 diffractometer working with Cu-Kα radiation (λ = 1.5418 Å) over the 2θ range of 4-40° at room temperature. Thermogravimetric analyses (TGA) were carried out with the TA Q500 thermogravimetric analyzer under a heating rate of 10 oC min-1 to 800 oC in air. Elemental analyses (C, H and N) were carried out with a vario MICRO elemental analyzer. Surface areas and pore size distributions were measured by N2 adsorption isotherm at 77 K with a Micrometrics ASAP 2040 instrument. CO2 adsorption isotherms were measured at 273 and 298 K with a Micrometrics ASAP 2010. The liquid state UV-Vis spectra were recorded on a SHIMADZU UV-2450 UV-visible spectrophotometer. Synthesis of (Cu4I4)[Cu2(PDC)2DMF2]2•2DMF•H2O (JLU-Liu15). A mixture of H2PDC (0.008 g, 0.047 mmol), CuI (0.016 g, 0.084 mmol), Dabco (0.010 g, 0.089 mmol), HNO3 (200 µL, 2.7 M in DMF) and DMF (1 mL) was sealed in a 20 mL vial and kept in an oven at 85 °C for
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48 h, and then cooled to room temperature. The green block crystals were collected and air-dried (65% yield based on CuI). Anal. Calcd for Cu8I4C46H56O22N10: C 26.10; H 2.67; N 6.62%; found: C 28.28; H 3.17; N 6.93%. Synthesis of (Cu4I4)[Cu3(CPNA)3(Dabco)0.5DMF3]•4DMF•4H2O (JLU-Liu16). A mixture of H2CPNA (0.004 g, 0.016 mmol), CuI (0.016 g, 0.084 mmol), Dabco (0.010 g, 0.089 mmol), HNO3 (275 µL, 2.7 M in DMF), 1,4-Dioxane (0.4 mL) and DMF (1 mL) was sealed in a 20 mL vial and kept in an oven at 105 °C for 12 h, and then cooled to room temperature. The green block crystals were collected and air-dried (76% yield based on CuI). Anal. Calcd for Cu7I4C63H84O23N11: C 32.67; H 3.66; N 6.65%; found: C 34.63; H 4.64; N 8.82%. Synthesis of (Cu4I4)[Cu3(CPNA)3(H2O)0.5DMF3]•4DMF•4H2O (JLU-Liu17). A mixture of H2CPNA (0.008 g, 0.032 mmol), CuI (0.016 g, 0.084 mmol), HBF4 (50 µL) and DMF (1 mL) was sealed in a 20 mL vial and kept in an oven at 85 °C for 12 h, and then cooled to room temperature. The green block crystals were collected and air-dried (71% yield based on CuI). Anal. Calcd for Cu7I4C60H79O23.5N10: C 31.76; H 3.51; N 6.17%; found: C 29.14; H 2.69; N 4.57%. The phase purity of as-synthesized samples was confirmed by the evident similarities between the calculated and the experimental PXRD patterns (Fig. S1-3). The IR spectra for compounds are shown in Supporting Information (Fig. S7, 8). X-ray crystallography Single-crystal X-ray diffraction measurements were carried out on a Bruker Apex II CCD diffractometer for JLU-Liu15 and JLU-Liu17, Rigaku R-AXIS RAPID diffractometer for JLULiu16 with graphite monochromated Mo Kα (λ = 0.71073 Å) radiation at 293 K. Data processing
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was accomplished with the SAINT processing program.47 The structures of these compounds were solved by direct method and refined on F2 by full-matrix least-squares with the SHELEX97 program.48 All the non-hydrogen atoms were refined with anisotropic displacement parameters. The hydrogen atoms on the aromatic rings were located geometrically with isotropic thermal parameters of 1.2 times those of the attached carbon atoms. The void volume of these compounds can be obtained by the PLATON/SQUEEZE program,49-50 and the related topology analysis is obtained from the TOPOS software.51 Formulas of these three compounds were designated from the crystallographic data combined with experimental ones (element analyses, TGA). Crystallographic data for JLU-Liu15-17 (1404803-1404805) have been deposited with Cambridge Crystallographic Data Centre. Data can be obtained free of charge upon request at www.ccdc.cam.ac.uk/data_request/cif. The summary of the crystallographic data and related parameters can be seen in Table 1, while the selective bond lengths and angles of these compounds are given in Tables S1-S2 (†ESI). RESULTS AND DISCUSSION In the synthesis of these three compounds, CuI was used as the inorganic metal source which can be decomposed in situ to form both the copper paddle wheel and Cu4I4 cluster, thereby afford the binodal inorganic SBUs. Besides, in JLU-Liu15, Dabco was used merely as the structural directing agent to facilitate the formation of crystals. However, in JLU-Liu16, Dabco can be regarded as the bridging linker between two nearby Cu4I4 clusters. The coexistence of Cu+ and Cu2+ can be also certified by XPS measurements (†Fig. S11). Structure descriptions
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Crystal structure of JLU-Liu15. JLU-Liu15 crystallizes in the tetragonal space group P4/nmm, the asymmetric unit consists of one crystallographic independent Cu(II) ion (Cu1), one Cu(I) ion (Cu2), half of one PDC2- anion, one I- anion (I1) and one terminal coordinated water molecule (O3). The Cu(I), Cu(II), I1 atom and the ligand are located on the crystallographically-imposed 2-fold axis. The Cu(II) ion is five coordinated with oxygen atoms with the average Cu-O bond distance of 2.667 Å, and two Cu(II) ions further form the binuclear Cu2(CO2)4 paddle wheel. The Cu(I) ion links to the I1 atom and form the Cu4I4 cluster which are further coordinated by the N atom from ligand, with the average bond distance of 2.727(6) Å for Cu-I and 2.033(2) Å for CuN. In JLU-Liu15, the ligand PDC2- linked to two paddle wheels and one Cu4I4 cluster can be regarded as a 3-connected node, the paddle wheel unit can be thought as a 4-connected square node, while Cu4I4 cluster can be viewed as a 4-connected tetrahedral node (Fig.1). The 3D structure is formed by the linkage of two inorganic SBUs and the organic ligand. Notably, it contains one dimensional channels with the diameter of 10.05 Å × 5.51 Å along the [100] direction (considering the Van der Waals radii). A better insight into the framework can be provided by the topological analysis of TOPOS, JLU-Liu15 illustrated a ternary framework built of triangle, square and tetrahedral nodes with under lying (3,4,4)-c sqc5588 net, which can be found in the EPINET database,52-53 the point symbol is {62.82.102}2{62.84}{63}4. The void volume of JLU-Liu15 after removal of guest solvent molecules is ca. 56 % by using PLATON/SQUEEZE. Crystal structure of JLU-Liu16. JLU-Liu16 crystallizes in the hexagonal space group P63/m, the asymmetric unit consists of two independent Cu(I) ions (Cu1, Cu2), two independent Cu(II) ions (Cu3, Cu4), one CPNA2- ligand, two I- anions (I1, I2), one third Dabco molecule coordinated to Cu2 ion and two terminal water molecules coordinated Cu(II) ions. Both of the
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Cu(II) ions with their terminal coordinated water molecules are located on the crystallographically-imposed 2-fold axis, while the nitrogen atom (N2) from the Dabco and nearby Cu2 and I2 atom are located on the crystallographically-imposed 3-fold axis. The Cu1 and Cu2 coordinate with I1 and I2 to form a Cu4I4 cluster. In such a cluster, each Cu(I) or I- links three neighbouring I- or Cu(I) to form a distorted cubane unit. Cu1 is tetrahedrally coordinated to three I- anions and one nitrogen atom from the CPNA2- ligand with an average bond distance of 2.548(1)-2.964(2) Å for Cu-I and 1.973(6) Å for Cu-N, while Cu2 is coordinated to three I- ions and one µ2-Dabco molecule with an average bond distance of 2.649(6) Å for Cu-I and 2.635(2) Å for Cu-N. The intracubane Cu-Cu distances are 2.571(2) and 2.987(2) Å, the latter is slightly longer than those found in other structurally characterized Cu4I4L4 compounds (L = monodentate nitrogen-containing ligand). The Cu3 and Cu4 can form the classical binuclear Cu2(CO2)4 paddle wheel where each Cu(II) ion is five-coordinated by four oxygen atoms from four CPNA2- ligands and one terminal coordinated water molecule. In JLU-Liu16, the Cu4I4 cluster and binuclear Cu2(CO2)4 paddle wheel can be both regarded as 4-connected nodes, while the CPNA2- ligand formed a 3-connected node which linked two binuclear Cu2(CO2)4 paddle wheel and one Cu4I4 cluster (Fig. 2). Notably, the Cu4I4 clusters can be thought as further connected by the µ2-Dabco molecule between them, such linkage can be also found in previous reports.34 The effective linkage of the CPNA2- ligand, Dabco, the Cu4I4 cluster and binuclear Cu2(CO2)4 paddle wheel could
afford
a
3-D
(3,
4,
4)-connected
topology
with
the
point
symbol
of
{5.82}6{5.83.92}3{53.83}2. The void volume of JLU-Liu16 after the removal of guest solvent molecules is ca. 70 % by using PLATON/SQUEEZE. Crystal structure of JLU-Liu17. JLU-Liu17 crystallizes in the hexagonal space group P63/m, it reveals a similar structure as JLU-Liu16, except that the Cu4I4 clusters are linked by the µ2-
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H2O instead of µ2-Dabco (Fig. 2d, 3). The distances of Cu-I and Cu-O are 2.655-2.735 Å and 2.988(5) Å, respectively. The Cu4I4-O-Cu4I4 link configuration is really rare in the CuxIx hybrid materials, and only a few compounds with a Cu4I4-O-Cu4I4 dumbbell-like linkage have been reported.54-55 Such arrangement endows the µ2-H2O molecule with unprecedented linear coordination mode, while in most cases, µ2-H2O bridges metal atoms with angle in the range of 70-152o. It should be pointed out that the 180° Cu-O-Cu angle in the (Cu4I4)2O here is an uncommon fashion for µ2-H2O bridge. The coordination water molecule is also confirmed by the charge balance and IR spectra (†Fig. S7). And the void volume of JLU-Liu17 after the removal of guest solvent molecules is ca. 72 % by using PLATON/SQUEEZE. Comparisons of the ligands and structures It is well known that the selecting of metal and ligand for the construction of MOFs plays significant role on the structures obtained. In this work, JLU-Liu15 exhibits a (3,4,4)-c sqc5588 network by the assembly of H2PDC with the 4-connected square Cu2(CO2)4 paddle wheel and tetrahedral Cu4I4 SBUs. While in JLU-Liu16 and JLU-Liu17, they both adopt the same new topology with underlying (3,4,4)-c net. To verify that the selection of multiple O and N ligand is crucial in the synthesis of binodal MOFs as clarified here, two pure O including ligand with similar configuration, isophthalic acid and biphenyl-3,4'-dicarboxylic acid, were selected to react with CuI in the same conditions. However, only two previously reported topologies with copper paddle wheel SBUs can be obtained.56-57 It proved that selecting of ligand in this reaction system is critical and may help the construction of MOFs with diverse SBUs. Besides, the Dabco can just be regarded as the structural directing agent in JLU-Liu15, while performed as a bridging ligand in JLU-Liu16. Interestingly, though the JLU-Liu16 and JLU-Liu17 possess the same topological structures, the linkage between the Cu4I4 clusters is different. As shown in Figure 3,
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in JLU-Liu16, two nearby Cu4I4 clusters can be easily bridged by the µ2-Dabco. While in JLULiu17, the µ2-H2O adopts the rare linear configuration. The Cu-Cu distance between two Cu4I4 clusters changes slightly from 6.740 to 4.971 Å. Though great effort were paid to introduce some other similar µ2 molecules, such as 4,4'-bipyridine, pyrazine and ethane-1,2-diamine into such system, the results show that Dabco is especially useful here. A much clear insight into these three frameworks can be seen in Figure 4, these frameworks can be deconstructed into cages in which triangular moieties can be isolated from the frameworks. It’ particular interesting to see that the elongated ligand H2CPNA used in this work can lead to the formation of Cu4I4-µ2DabcoCu4I4 or Cu4I4-µ2H2O-Cu4I4 linkage in the triangular.
Gas adsorption behaviours Though JLU-Liu16 and JLU-Liu17 exhibit large void volume, only JLU-Liu15 possesses moderate gas adsorption behaviour among the three compounds. The frameworks of JLU-Liu16 and JLU-Liu17 are collapsed after removal of guest molecules or activation at vacuum. The assynthesized samples of JLU-Liu15 were solvent exchanged with methanol for about 3 d and activated for 10 h under room temperature for the gas adsorption studies. The porous properties of JLU-Liu15 were investigated by N2 adsorption measurement at 77K. As shown in Figure 5, JLU-Liu15 exhibits Type I nitrogen gas adsorption isotherm according to the IUPAC classification. The Brunauer-Emmett-Teller (BET) surface area was calculated to be ca. 762 m2 g-1 while the Langmuir surface area of ca. 1031 m2 g-1. To our knowledge, JLU-Liu15 exhibits the highest surface area among the MOFs or inorganic-organic materials based on Cu4I4 cluster SBUs.35 The pore size distribution of JLU-Liu15 calculated by using a nonlocal density
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functional theory (NLDFT) method suggests a microporous feature with the pore size of about 0.6 nm, which corresponds with the one measured from the crystal structure. The CO2 and small hydrocarbons gas adsorption of JLU-Liu15 was also measured (273 and 298 K). At 273 K and 1 bar, the amount of CO2 uptake reaches 89.3 cm3 g-1(ca. 3.99 mmol g-1). Such value is higher than InOF-8 (66.2 cm3 g-1, 2.95 mmol g-1) reported by Hong’s group, which is another binodal structure constructed by In3O(CO2)6 and Cu4I4 clusters.46 To evaluate the affinity of JLU-Liu15 to CO2, the isosteric heat (Qst) was also calculated. At zero-coverage, the Qst of CO2 shows the moderate value of ca. 30 kJ mol-1. The adsorption isotherms of CH4, C2H6 and C3H8 are also measured at 273 and 298 K under 1 bar, respectively. The maximum adsorption for CH4 is 39.5 and 27.3 cm3 g-1, C2H6 is 97.3 and 77.7 cm3 g-1 and C3H8 is 104.9 and 87.0 cm3 g-1, respectively. At zero loading, Qst of CH4, C2H6 and C3H8 adsorption is 23, 34 and 40 kJ mol-1, respectively, as estimated from the sorption isotherms at 273 and 298 K (†Fig. S12 to S14). The CO2/CH4 (50% and 50%, 5% and 95%) adsorption selectivity was calculated by ideal adsorption solution theory (IAST) based on the experimental single-component isotherms fitted by the dual site Langmuir Freundlich (DSLF) model at 298 K and 1 bar. The selectivity of CO2 over CH4 for JLU-Liu15 according to the experimental data is 3.05 and 3.1 (†Fig. S15). Furthermore, the selectivities of C2H6/CH4 and C3H8/CH4 are 27.8 and 461.5, respectively (†Fig. S15). It is highlighted that the high selectivity of C2H6/CH4 and C3H8/CH4 are much higher than many reported MOFs, such as JLU-Liu543, JLU-Liu1858 and JLU-Liu 22.59 Iodine adsorption experiments Inspired by the iodine adsorption study of JLU-Liu14 reported by our group previously,60 the iodine adsorption behaviour of JLU-Liu15 was also investigated, it exhibits both higher I2
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adsorption amount per unit and higher average release rate than JLU-Liu14. The samples of JLU-Liu15 were solvent exchanged by methanol for 24 h. Then, about 80 mg of the activated samples were soaked in the cyclohexane solution of I2 (0.01 M, 3 mL) in a sealed vial and kept at room temperature. As illustrated in Figure 6, the I2 adsorption process accompanied with fading of vial colour from claret red to light pink after 72 h in a cyclohexane solution of I2 and reaches a total adsorption value of 3.65 I2 molecules per formula unit, while the I2 release process can be directly observed with change of colour to dark brown after 24 h with the samples immersed in ethanol. It is noteworthy that the uptakes of I2 being adsorbed per formula unit is higher than MOF {[Zn3(D-Llac)2(pybz)2]·3I2}n reported by Zeng’s group60 and JLU-Liu14 reported by us.61 The release dynamic process can be observed by the UV-Vis spectra, as shown in Figure 7. The release of I2 increases sharply and then gently, with an average rate of 1.82×10-6 mol·L-1·min-1 according to the standard curve (†Fig. S5), which is faster than JLU-Liu14. CONCLUSION In summary, on the basis of the hetero-O, N donor ligands pyridine-3,5-dicarboxylic acid and 5-(4’-carboxylphenyl) nicotinic acid, three new MOFs with ternary SBUs have been successfully constructed. JLU-Liu15 shows a (3,4,4)-c sqc5588 topology. While JLU-Liu16 and JLU-Liu17 adopt the same new topology with under lying (3,4,4)-c net. Besides, Dabco was used as the structural directing agent in JLU-Liu15 while can be regarded as the bridging ligand in JLULiu16. Furthermore, the structural difference between JLU-Liu16 and JLU-Liu17 is the bridging linkers between two nearby Cu4I4 clusters, which in JLU-Liu16 is µ2-Dabco molecule while in JLU-Liu17 is µ2-water molecule. The successful employment of diverse Cu2(CO2)4 paddle wheel and Cu4I4 cluster inorganic building units in these compounds reveals that the usage of hetero-O, N donor ligands could be an useful method to generate unique structures and
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topologies with multiple SBUs. Furthermore, JLU-Liu15 exhibit high gas adsorption behaviour and I2 uptake and release features. ASSOCIATED CONTENT Supporting Information. Crystallographic data in CIF format, table for selected bonds and distances for JLU-Liu15-17, PXRD patterns, IR spectra, thermogravimetric analysis, UV-Vis spectra, XPS spectra for JLULiu15-17. This material is available free of charge via the Internet at http://pubs.acs.org. AUTHOR INFORMATION Corresponding Author *(Y.L.) Fax: +86-431-85168624. E-mail:
[email protected]. *(D.-S.L.) E-mail:
[email protected]. Notes The authors declare no competing financial interests. ACKNOWLEDGMENT The authors gratefully acknowledge the financial support of the Natural Science Foundation of China (Nos. 21373095, 21371067 and 21171064) and Key Laboratory of Polyoxometalate Science of Ministry of Education. REFERENCES [1] Li, H.; Eddaoudi, M.; O'Keeffe, M.; Yaghi, O. M. Nature 1999, 402, 276. [2] Long, J. R.; Yaghi, O. M. Chem. Soc. Rev. 2009, 38, 1213. [3] Zhou, H.-C.; Long, J. R.; Yaghi, O. M. Chem. Rev. 2012, 112, 673.
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Figure Captions Scheme 1 Schematic structure illustration of hetero-O, N donor ligands H2PDC and H2CPNA. Figure 1 A description of JLU-Liu15: (a) The coordination environment of ligand H2PDC viewed as a 3-coonected triangular node, the paddle wheel viewed as a 4-coonected square node, the Cu4I4 cluster viewed as a 4-connected tetrahedral node; (b) the 3D framework of JLU-Liu15; (c) polyhedral view of the topology; (d) the (3,4,4)-c net sqc5588 topology; (e) the tiling illustration. Figure 2 A description of JLU-Liu16 and 17: (a) The coordination environment of ligand CPNA2- viewed as a 3-coonected triangular node; (b) the paddle wheel viewed as a 4-coonected square node; (c) the Cu4I4 cluster viewed as a 4-connected tetrahedral node in JLU-Liu16; (d) the Cu4I4 cluster viewed as a 4-connected tetrahedral node in JLU-Liu17; (e) the 3D framework of JLU-Liu16; (f) polyhedral view of the topology; (g) the (3,4,4)-c net; (h) the tiling illustration. Figure 3 Comparison of the bridging part between two nearby Cu4I4 clusters for JLU-Liu16 and JLU-Liu17. Figure 4 The triangular moieties isolated from the frameworks of JLU-Liu15-17. Figure 5 (a) The N2 adsorption and desorption isotherm of JLU-Liu15 at 77 K; (b) Pore size distribution of JLU-Liu15; (c) CO2 adsorption isotherms of JLU-Liu15 at 273 and 298 K; (d) Isosteric heat of adsorption for CO2. Figure 6 (a) Photographs of time-dependent I2 adsorption process of JLU-Liu15 in cyclohexane; (b) Photographs of time-dependent I2 release process of JLU-Liu15 in ethanol. Figure 7 (a) The UV-Vis spectra of I2 release for JLU-Liu15 (outside); (b) The dynamic intensity plot (monitored at 248 nm) vs t (inside).
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Scheme 1
Figure 1
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Figure 2
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Figure 3
Figure 4
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Figure 5
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Figure 6
Figure 7
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Table 1 Crystallographic data for JLU-Liu15-17. compound formula fw temp (K) wavelength (Å) cryst syst a (Å) b (Å) c (Å) V (Å3) Z F(000) θ range (deg) reflns collected/unique Rint data/restraints/params GOF on F2 R1, wR2 [I>2σ(I)] R1, wR2 (all data)
JLU-Liu15 Cu8I4C46H56O22N10 2132.92 293(2) 0.71073 Tetragonal, P4/nmm 19.209(3) 19.209(3) 10.991(2) 4055.7(14) 2 2060 1.499 to 25.333 25800 / 2055 0.0285 2055 / 14 / 105 1.036 0.0264, 0.0776 0.0292, 0.0790
JLU-Liu16 Cu7I4C63H84O23N11 2315.79 293(2) 0.71073 Hexagonal, P63/m
JLU-Liu17 Cu7I4C60H79O23.5N10 2268.71 293(2) 0.71073 Hexagonal, P63/m
27.538(4) 27.538(4) 20.139(4) 13225(5) 4 4552 3.033 to 27.485 93448 / 10349 0.1080 10349 / 0 / 223 0.940 0.0509, 0.1276 0.1389, 0.1485
28.135(4) 28.135(4) 19.200(4) 13162(5) 4 4448 1.350 to 18.884 36643 / 3625 0.0647 3625 / 6 / 213 1.099 0.0597, 0.1822 0.0749, 0.1929
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Table of Contents Assembly of three Metal-Organic Frameworks with Binodal Inorganic building units and hetero-O, N donor ligand Xiaolong Luo,a Libo Sun,a Jun Zhao,b Dong-Sheng Li,*,b Dongmei Wang,a Guanghua Li,a Qisheng Huoa and Yunling Liu*,a
Three new MOFs, JLU-Liu15-17 have been constructed by using hetero-O, N donor ligands. All of these three compounds are composed of the binodal inorganic Cu2(CO2)4 paddle wheel and Cu4I4 cluster building units. JLU-Liu15 exhibits high N2 and CO2 adsorption behaviours as well as I2 uptake and release feature.
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