Effect of lanthanide contraction on structures of lanthanide coordination polymers based on 5-aminoisophthalic acid and oxalate

Inorganic Chemistry Communications 23 (2012) 127–131

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Effect of lanthanide contraction on structures of lanthanide coordination polymers based on 5-aminoisophthalic acid and oxalate Xia Zhao, Dan-Xian Wang, Qian Chen, Jian-Biao Chen, Guo-Ying Lin, Shan-Tang Yue ⁎, Yue-Peng Cai School of Chemistry and Environment, South China Normal University, Guangzhou 510006, PR China

a r t i c l e

i n f o

Article history: Received 25 May 2012 Received in revised form 22 June 2012 Accepted 25 June 2012 Available online 16 July 2012 Keywords: Hydrothermal synthesis Lanthanide contraction Topology Luminescence Magnetism

a b s t r a c t Two series of lanthanide coordination polymers with formular [Ln(Haip)(ox)(H2O)] (type I) (Ln = Ce(1), Pr(2), Nd(3), Sm(4), Eu(5), Gd(6), Tb(7)) and [Ln2(aip)2(ox)(H2O)]·H2O (type II) (Ln = Dy(8), Ho(9), Er(10), Tm(11)) have been synthesized by hydrothermal reactions of 5-aminoisophthalic acid (H2aip) and oxalate (ox) with corresponding lanthanide nitrates or lanthanide oxides. Complexes 1–7 (type I) are isostructural and possess 6-connected 2D layer structure with Schläfli symbol (3 6;46;53). Complexes 8–11 (type II) are also isomorphous and feature 9-connected 3D framework with Schläfli symbol (312;416;57;6). The solid-state luminescent properties of 5 and 7 containing Eu 3+ and Tb3+ were measured at room temperature. The magnetic properties show complexes 6 and 8 have antiferromagnetic behavior. Furthermore, infrared (IR), thermogravimetric analyses (TGA), elemental analyses (EA), powder X-ray diffraction (PXRD) of these complexes are also investigated. © 2012 Elsevier B.V. All rights reserved.

The rational design and synthesis of lanthanide metal-organic frameworks (LMOFs) have attracted increasing interest owing to their fascinating structural topologies and potential applications as functional materials in many fields, such as luminescence, catalysis, magnetism, gas storage and separation [1–5]. Because of the high and varies coordination geometry of lanthanides, and the final structures are influenced by various factors, such as the metal/ligand ratios, solvent preference, pH values and the temperature, it is difficult to control the synthetic reactions. In addition, the ionic radius of the Ln ions decrease with increasing atomic number, which is often referred as lanthanide contraction may also effects the coordination number and lead to diversity in crystal structure [6,7]. Nevertheless, due to the nature of Ln(III) ions with partially filled 4f orbitals, large radii, and high coordination numbers, they always show characteristic luminescent emissions and generally possess a large anisotropic magnetic moment arising from a large number of spins and strong spin-orbit coupling [8]. As a result, studies on LMOFs are expanding rapidly, and a lot of investigations on the lanthanide frameworks have been published recently [6,7,9,10]. Generally, the Ln ions prefer O- to N-donors. Thus, the ligands with oxygen or hybrid oxygen-nitrogen atoms, for example, imidazolecarboxylate, pyridinecarboxylate, pyrazinecarboxylate and benzenepolycarboxylate, can be used to construct LMOFs [11–14]. In these kinds of ligands, rigid polycarboxylic acids, especially aromatic

⁎ Corresponding author. Tel./fax: +86 20 39310187. E-mail address: [email protected] (S.-T. Yue). 1387-7003/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.inoche.2012.06.025

dicarboxylic acids, are frequently used to link lanthanide ions or lanthanide clusters. Until now, most of the LMOFs are built from just one type of multicarboxylate ligand, if adding the auxiliary ligands in the synthesis of LMOFs may not only result in new structure types but also bring interesting properties. The second ligands such as carboxylic acid [15], sulfonic acids [16], or oxalate anions [17], etc. have been found to be an effective synthetic method in the synthesis of MOFs, since these molecules can act as pillars between neighboring layers. With the above in mind, we chose 5-aminoisophthalic acid and oxalate acid as mixed ligands to construct LMOFs based on the following considerations: (1) H2aip, as a derivative of the V-shaped ligand isophthalic acid (H2ip), is a good spacer and has been widely used in the assembly of coordination polymers for its rich coordination modes [18]; (2) oxalate, as one of the simplest bisbidentate connectors, can facilitate the formation of extended structures by connecting metal centers [19]. Taking account of the above, we would like to synthesize and explore new LMOFs with H2aip and oxalate ligands and different lanthanide ions. Herein, a series of novel Ln coordination polymers based on H2aip and oxalate mixed ligands, namely, {[Ln(Haip)(ox)(H2O)]}n (Type I, Ln=Ce 1, Pr 2, Nd 3, Sm 4, Eu 5, Gd 6, Tb 7; Haip=5-aminoisophthalic acid, ox= oxalate), {[Ln2(aip)2(ox)(H2O)]·H2O}n (Type II, Ln=Dy 8, Ho 9, Er 10, Tm 11) were synthesized under hydrothermal conditions (Scheme 1) and characterized by elemental analyses, IR, TGA, fluorescent measurements, magnetic measurements, and single-crystal X-ray diffraction analyses [20]. In the FT‐IR spectra of compounds 1–11, the absorption bands in the range of 3600–3130 cm−1 should be ascribed to the characteristic peaks of OH vibration. The strong vibrations appeared around 1630 and

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Scheme 1. The synthetic route of 1–11.

1380 cm−1 correspond to the asymmetric and symmetric stretching vibrations of the carboxylate group, respectively. Single crystal X-ray analysis reveals [21] that 1–7 crystallize in the Monoclinic space group C 2/c. Both Haip and oxalate ligands have contributed to the molecular structure of them, forming mixed-ligand complexes with 2D layer-like structure. Because these complexes are isostructural, here only the structure of 1 is described in detail. As shown in Fig. 1a, the asymmetric unit of 1 contains one crystallographically independent Ce(III) ions, one partly deprotonated Haip ligand, one full deprotonated oxalate ligand, and one coordinated water molecule. The Ce(III) atom is nine-coordinated with a tricapped trigonal prism geometry by four oxygen atoms from the Haip ligands, four oxygen atoms from two different oxalate ligands, together with one oxygen from coordinated water molecule, respectively. The Ce\O bond distances range from 2.463(2) to 2.648(2) Å. The bond angles of O\Ce\O are in the range of 50.25(7) to 146.78(8)°. In complex 1, Haip ligand exhibits only one coordination mode. Its carboxylate groups are full deprotonated, while the amino group is protonated. One of the carboxylate coordinates to Ce(III) center through chelating mode; The other one shows bis-bidentate coordination mode, a pair of Haip ligands connect the adjacent Ce(III) ions forming a dinuclear unit with a Ce···Ce distance of 5.480 Å. Due to the coordination mode of Haip ligands, they link the units to form

1D infinite chain parallel to bc plane (Fig. 1b). On the other hand, the oxalate ligands also link the dinuclear units to generate a one-dimension (1D) infinite zigzag chain (Fig. 1b) adopting a single tetradentate μ2-η 1, η 1, η 1, η 1 coordination mode. The 1D chains are further bridged through Haip and oxalate ligands extending to 2D framework (Fig. 1c). In this case, the oxalate and Haip ligands can be viewed as connectors; the Ce atoms function as six-connected nodes (Fig. 1d). As a result, the 2D framework can be reduced to a 6-connected net with Schläfli symbol (3 6;4 6;5 3) by analysis of TOPOS 4.0 [22]. The reaction of H2aip and H2ox with Ln2O3 under the same hydrothermal condition generates four 3D coordination polymers 8–11 with type II structure. Here compound 8 was selected to represent the structure of type II. Single crystal X-ray analysis [21] reveals that 8 crystallize in the Orthorhombic space group Pnnna. There are one crystallographically independent Dy(III) ions, one-half full deprotonated oxalate ligand, one full deprononated aip ligand, one coordinated water molecule and one free water molecule in the asymmetric unit of 8. As

Fig. 1. (a) View of the asymmetric unit of complex 1. (b) Two types of 1D infinite chain. (c) View of 2D layer structure constructed by Haip and oxalate ligands in ab plane. (d) View of 6-connected net in ab plane. (All H atoms were omitted for clarity.) (a): − x, − y, − z; (b): x, 1 + y, z; (c):0.5 − x, y − 0.5, 0.5 − z.

Fig. 2. (a) View of the asymmetric unit of complex 8. (b) View of 1D infinite chain constructed by aip ligands. (c) View of 2D layer structure. (d) View of 3D networks based on 2D layers and oxalate ligands. (e) View of 9-connected net in ab plane. (All H atoms were omitted for clarity.) (a): 2−x, 0.5+y, 0.5+z); (b): 2−x, −y, 2−z; (c): 2.5−x, −y, z.

X. Zhao et al. / Inorganic Chemistry Communications 23 (2012) 127–131

Fig. 3. Solid-state emission spectrum of 5 at room temperature (Ex = 395 nm).

shown in Fig. 2a, Dy(III) is eight-coordinated in a bicapped trigonal prismatic coordination geometry by five oxygen atoms from the aip ligands, two oxygen atoms from oxalate ligands and one oxygen atom from coordinated water molecule, respectively. The Dy\O bond distances range from 2.227(7) to 2.602(7) Å. The bond angles of O\Dy\O are in the range of 51.4(2) to 157.1(3)°. The coordination modes of H2aip ligand in complexes 1 and 8 are distinguishing. In complex 8, aip ligand also exhibits only one coordination mode. Its carboxylate groups are full deprotonated and the amino group is not protonated in this case. One of the carboxylate coordinates to a Dy(III) center uses chelating mode, and one of oxygen atom in this carboxylate coordinates to another Dy(III) center at the same time. The rest of carboxylate coordinates to two metal centers through bis-bidentate coordination mode which is similar to that of complex 1. A pair of aip ligands connects the adjacent Dy(III) metal centers to form Dy(III)···Dy(III) dinuclear units which are similar to the Ce(III)···Ce(III) units in type I. Because of the coordination mode of aip ligands, the units are linked to produce 1D infinite chain (Fig. 2b) and the chains are also extended by aip ligands to come into being a 2D layer structure (Fig. 2c). Furthermore, these layers are connected by the oxalate ligands to give rise to 3D frameworks (Fig. 2d). From the topological point of view, the oxalate and aip ligands can be simplified as connectors; the Dy atoms act as nine-connected nodes. As a result, the 3D framework can be reduced to a 9-connected net (Fig. 2e) with Schläfli symbol (3 12;4 16;5 7;6) by analysis of TOPOS 4.0 [22]. Type I and type II were synthesized from similar reaction condition, the different crystal structures obtained provide a fair assessment of the critical impacts of lanthanide construction. In these compounds, oxalate ligand adopts same coordination mode and the coordination modes of H2aip are distinct in type I and type II, the Ln ions in compounds 1–11 are all trivalent while they adopt different

Fig. 4. Solid-state emission spectrum of 7 at room temperature (Ex = 351 nm).

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coordination mode. In type I, Ln ions are nine-coordinated by two Haip ligands, two oxalate ligands and one coordinated water molecule; in type II, Ln ions are eight-coordinated by four aip ligands, one oxalate ligand and one coordinated water molecule, it may be the lanthanide contraction effect that leads to the different crystal structures. Moreover, the average Ln\O bond lengths among the compounds 1–11 have also been compared. The average lengths between lanthanide and O atoms are decreasing continuously from 2.543(1), 2.525(2), 2.511(3), 2.480(4), 2.473(5), 2.465(6), 2.449(7), 2.379(8), 2.375(9), 2.367(10) to 2.351(11) Å. The lanthanide compounds have shown good luminescent properties for their high color purity with high quantum efficiency, so the solid-state luminescent properties of 5 and 7 containing Eu(III), Tb(III) were investigated at room temperature. As shown in Fig. 3, the emission spectrum of 5 upon excitation at 395 nm exhibits the characteristic transition of Eu(III) ion. They are attributed to 5 D0 → 7FJ (J = 0 → 4) transitions, i.e. 579 nm ( 5D0 → 7 F0), 592 nm ( 5D0 → 7 F1), 618 nm ( 5D0 → 7 F2), 651 nm ( 5D0 → 7 F3), 697 nm ( 5D0 → 7 F4). 5D0 → 7 F1 and 5D0 → 7 F2 are the most intense transitions. It is to be noted that the 5D0 → 7 F1 transition is a magnetic dipole transition, and its intensity varies with the crystal field strength acting on Eu(III). On the other hand, the 5D0 → 7 F2 transition is an electric dipole transition and is extremely sensitive to chemical bonds in the vicinity of Eu(III). Furthermore, the intensity of the 5 D0 → 7 F2 transition increases as the site symmetry of Eu(III) decreases. Therefore, the intensity ratio of the 5D0 → 7 F2 transition compared with that of the 5D0 → 7 F1 transition has been widely used as a measure of the coordination state and the site symmetry of the rare earth ions [23]. For compound 5, the intensity of the 5 D0 → 7 F2 transition is stronger than that of the 5D0 → 7F1transition; the intensity ratio I( 5D0 → 7 F2)/I( 5D0 → 7 F1) is ca. 1.09, which suggests that the Eu(III) ions in 5 have a centrosymmetric coordination environment. Compound 7 yields green light and exhibits the

−1 Fig. 5. (a) Temperature dependence of χMT and χM for 6 at 5 KOe between 2 and −1 300 K. (b) Temperature dependence of χMT andχM for 8 at 1 KOe between 2 and 300 K.

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Tb3+ (7) exhibit characteristic lanthanide-centered luminescence. Furthermore, the magnetic properties of complexes 6 and 8 have been investigated, they all show antiferromagnetic behaviors. Acknowledgments We are thankful for financial support from NSFC (Grants 20971047 and U0734005), Guangdong Provincial Science and Technology Bureau (Grant 2008B010600009) and Key Research Program of Guangdong Provincial Universities Science and Technology innovation (Grant cxzd1020). Fig. 6. The PXRD patterns (a) simulated based on the X-ray single-crystal diffraction data of 7, (b) for as-synthesized 7; (c) simulated based on X-ray single-crystal diffraction data of 10, (d) for as-synthesized 10.

characteristic emission bands at 489 nm and 544 nm (Fig. 4) correspond to 5D4 → 7 F6 and 5D4 → 7 F5, while the weaker emission bands at 588 nm, 623 nm and 652 nm originate from 5D4 → 7 F4, 5 D4 → 7 F3 and 5D4 → 7 F2. The solid-state dc magnetic susceptibility measurements for compounds 6 and 8 were performed in the range of 2–300 K under the field of 5 KOe and 1KOe, respectively. The magnetic behavior of 6 is shown in Fig. 5a, as plots of χMT versus T and 1/χM versus T, where χM is the molecular magnetic susceptibility. At room temperature, the χMT is 7.60 cm 3·K·mol −1, close to the spin-only value 7.78 cm 3·K·mol −1 expected for one isolated Gd III cations [6]. The χMT value steadily decreased to 7.48 cm 3·K·mol −1 with the temperature decreasing in the range of 300–2 K, which reveals an antiferro−1 magnetic behavior in 6. The χM versus T obeys the Curie–Weiss law, χ = C/(T − θ), with Curie constant C = 7.60 cm 3·K·mol −1 and Weiss constant θ = − 0.30 K. The negative Weiss constant also gives the evidence of antiferromagnetic interactions existing in compound 6. The magnetic behavior of 8 is shown in Fig. 5b, as plots of χMT versus T and 1/χM versus T, where χM is the molecular magnetic susceptibility. The room-temperature χMT value is 26.36 cm3·K·mol−1, which is slightly lower than the expected value 28.34 cm3·K·mol−1 for two isolated DyIII ion [6]. As the temperature lowered from 300 K to 2 K, the χMT value decreased steadily from 26.36 cm3·K·mol−1 to 21.83 cm3·K·mol−1, which reveals an antiferromagnetic behavior in compound 8. The temperature dependent 1/χM value obey the Curie–Weiss law with Curie constant C = 26.41 cm 3·K·mol − 1 and Weiss constant θ = − 2.83 K. The negative Weiss constant also gives the evidence of antiferromagnetic interactions existing in compound 8. Owing to the similarity of the structures for 1–7 and 8–11, complexes 5 and 10 were selected for the TGA to examine the thermal stability of both complexes. The thermogravimetric analyses of the two complexes were done from 30 to 800 °C at a heating rate of 10 °C/min in dry air atmosphere. As shown in the Supporting Information Fig. S1, TGA curves of the compounds reveal that they are stable up to approximately 350 °C and 400 °C, respectively, while beyond these temperatures, their networks start to decompose. Complexes 7 and 10 were characterized by powder X-ray diffraction at room temperature, simulated and experimental powder X-ray diffraction (PXRD) patterns are shown in Fig. 6. All the peaks presented in the measured curves closely match in the simulated curves generated from single-crystal diffraction data, which clearly confirms the phase purity of the as-prepared products. In summary, by using the hydrothermal reaction, eleven Ln(III)-based coordination polymers containing the mixed ligands of Haip/aip and oxalates have been prepared. X-ray crystallography revealed that the polymers have 2D layer networks (1–7) and novel 3D networks (8–11). Among these complexes, the average Ln\O bond lengths decrease shows the lanthanide contraction effect. The complexes of Eu3+ (5) and

Appendix A. Supplementary data CCDC 873280–873290 contain the supplementary crystallographic data for 1–2. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/ data_request/cif, or from the Cambridge Crystallographic Data Centre, 12 Union Road, CambridgeCB2 1EZ, UK[Fax: + 44(1223)336-033; E-mail: [email protected]]. Supplementary materials related to this article can be found online at http://dx.doi.org/10.1016/j. inoche.2012.06.025. References [1](a) K.A. White, D.A. Chengelis, K.A. Gogick, J. Stehman, N.L. Rosi, S. Petoud, Near-infrared luminescent lanthanide MOF barcodes, J. Am. Chem. Soc. 131 (2009) 18069–18071; (b) 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, A luminescent mixed-lanthanide metal-organic framework thermometer, J. Am. Chem. Soc. 134 (2012) 3979–3982; (c) B. Zheng, D.J. Zhang, Q.S. Huo, Y.L. Liu, Syntheses, structures and luminescence properties of two novel lanthanide metal-organic frameworks based on a rigid tetracarboxylate ligand, Inorg. Chem. Commun. 16 (2012) 70–73. [2](a) W. Huang, D.Y. Wu, P. Zhou, W.B. Yan, D. Guo, C.Y. Duan, Q.J. Meng, Luminescent and magnetic properties of lanthanide thiophene-2, 5-dicarboxylate hybrid materials, Cryst. Growth Des. 9 (2009) 1361–1369; (b) H.B. Zhang, Y. Peng, X.C. Shan, C.B. Tian, S.W. Du, Lanthanide metal organic frameworks based on octahedral secondary building units: structural, luminescent, and magnetic properties, Inorg. Chem. Commun. 14 (2011) 1165–1169. [3](a) W.G. Lu, L. Jiang, X.L. Feng, T.B. Lu, Three-dimensional lanthanide anionic metal-organic frameworks with tunable luminescent properties induced by cation exchange, Inorg. Chem. 48 (2009) 6997–6999; (b) K. Kuriki, Y. Koike, Plastic optical fiber lasers and amplifiers containing lanthanide complexes, Chem. Rev. 102 (2002) 2347–2356. [4](a) Y.W. Ren, J.X. Liang, J.X. Lu, B.W. Cai, D.B. Shi, C.R. Cai, H.F. Jiang, J. Chen, D. Zheng, 1, 4-phenylenediacetate-based Ln MOFs-synthesis, structures, luminescence, and catalytic activity, Eur. J. Inorg. Chem. (2011) 4369–4376; (b) C. Wang, Y.L. Wang, Z.X. Qin, Y. Ma, Q.L. Wang, L.C. Li, D.Z. Liao, Three lanthanide-radical complexes: synthesis, structure and magnetic properties, Inorg. Chem. Commun. 20 (2012) 112–116. (c) Y. Luo, G. Calvez, S. Freslon, K. Bernot, C. Daiguebonne, O. Guillou, Lanthanide aminoisophthalate coordination polymers: a promising system for tuable luminescent properties, (2011) 3705–3716. [5](a) X. Zhao, X.Y. Yu, T.L. Chen, Y.H. Luo, J.J. Yang, H. Zhang, A series of lanthanide compounds based on mixed aromatic carboxylate ligands: syntheses, crystal structures and luminescent properties, Inorg. Chem. Commun. 20 (2012) 247–251; (b) J. Xu, H.Z. Xing, Z.Q. Liang, J.H. Yu, R.R. Xu, A new lanthanide metal-organic framework with (3, 6)-connected topology based on novel tricarboxylate ligand, Inorg. Chem. Commun. 14 (2011) 978–981; (c) T. Devic, O. David, M. Valls, J. Marrot, F. Couty, G. Férey, An illustration of the limit of the metal organic framework's isoreticular principle using a semirigid tritopic linker obtained by “click” chemistry, J. Am. Chem. Soc. 129 (2007) 12614–12615. [6](a) Z.G. Gu, H.C. Fang, P.Y. Yin, L. Tong, Y. Ying, S.J. Hu, W.S. Li, Y.P. Cai, A family of three-dimensional lanthanide-zinc heterometal-organic frameworks from 4, 5-imidazoledicarboxylate and oxalate, Cryst. Growth Des. 11 (2011) 2220–2227; (b) J. Xu, J.W. Cheng, W.P. Su, M.C. Hong, Effect of lanthanide contraction on crystal structures of three-dimensional lanthanide based metal-organic frameworks with thiophene-2, 5-dicarboxylate and oxalate, Cryst. Growth Des. 11 (2011) 2294–2301; (c) M.F. Wu, M.S. Wang, S.P. Guo, F.K. Zheng, H.F. Chen, X.M. Jiang, G.N. Liu, G.C. Guo, J.S. Huang, Cryst. Growth Des. 11 (2011) 372–381. [7](a) Q.Y. Liu, L. Xu, Novel structure evolution of lanthanide-SIP coordination polymers (NaH2 SIP = 5-sulfoisophthalic acid monosodium salt) from a 1D chain to a 3D network as a consequence of the lanthanide contraction effect, Eur. J. Inorg. Chem. (2005) 3458–3466;

X. Zhao et al. / Inorganic Chemistry Communications 23 (2012) 127–131 (b) J.G. Wang, C.C. Huang, X.H. Huang, D.S. Liu, Three-dimensional lanthanide thiophenedicarboxylate framework with an unprecedent (4, 5)-connected topology, Cryst. Growth Des. 8 (2008) 795–798; (c) Z.H. Weng, D.C. Liu, Z.L. Chen, H.H. Zou, S. Qin, F.P. Liang, Two types of lanthanide coordination polymers of (2, 3-f)-pyrazino(1, 10)phenanthroline-2, 3-dicarboxylic acid: syntheses, structures, and properties, Cryst. Growth Des. 9 (2009) 4163–4170. [8](a) J. Xu, W.P. Su, M.C. Hong, Two lanthanide-natrium pillared-layer frameworks constructed from 4, 4′-oxybis (benzoic acid) and oxalate, Inorg. Chem. Commun. 14 (2011) 1794–1797; (b) C. Benelli, D. Gatteschi, Magnetism of lanthanide in molecular materials with transition-metal ions and organic radicals, Chem. Rev. 120 (2002) 2369–2388; (c) P. Wang, J.P. Ma, Y.B. Dong, R.Q. Huang, Tunable luminescent lanthanide coordination polymers based on reversible solid-state ion-exchange monitored by ion-dependent photoinduced emission spectra, J. Am. Chem. Soc. 129 (2007) 10620–10621. [9](a) Y.Q. Sun, J. Zhang, Y.M. Chen, G.Y. Yang, Porous lanthanide-organic open frameworks with helical tubes constructed from interweaving triple-helical and double-helical chains, Angew. Chem. Int. Ed. 44 (2005) 5814–5817; (b) J. Zhang, J. Huang, J. Yang, H.J. Chen, Two- and three-dimensional lanthanide metal-organic frameworks with hydroxyl-functionalized nicotinic acid and oxalate ligands, Inorg. Chem. Commun. 17 (2012) 163–168; (c) H.H. Song, Y.J. Li, Synthesis, crystal structure and luminescence properties of two novel lanthanide coordination polymers containing double chain, Inorg. Chim. Acta 361 (2008) 1421–1425. 10(a) W.G. Lu, L. Jiang, X.L. Feng, T.B. Lu, Three-dimensional lanthanide anionic metal-organic frameworks with tunable luminescent properties induced by cation exchange, Inorg. Chem. 48 (2009) 6997–6999; (b) C.X. Zhang, N.N. Sun, X.Y. Zhao, Y.Y. Zhang, Y.L. Guo, Syntheses, crystal structures, magnetic properties of two lanthanide-nitronyl nitroxide complexes (LnIII = GdIII, PrIII), Inorg. Chem. Commun. 14 (2011) 166–168. [11](a) L. Pan, X.Y. Huang, J. Li, Y.G. Wu, N.W. Zheng, Novel single- and double-layer and three-dimensional structures of rare-earth metal coordination polymers: the effect of lanthanide contraction and acidity control in crystal structure formation, Angew. Chem. Int. Ed. 39 (2000) 527–530; (b) J. Xia, B. Zhao, H.S. Wang, W. Shi, Y. Ma, H.B. Song, P. Cheng, D.Z. Liao, S.P. Yan, Two- and three-dimensional lanthanide complexes: synthesis, crystal structures, and properties, Inorg. Chem. 46 (2007) 3450–3458. [12](a) X.Q. Zhao, Y. Zuo, D.L. Gao, B. Zhao, W. Shi, P. Cheng, Syntheses, structures, and luminescence properties of a series of LnIII-BaII heterometal-organic frameworks, Cryst. Growth Des. 9 (2009) 3948–3957; (b) Y.P. Cai, X.X. Zhou, Z.Y. Zhou, S.Z. Zhu, P.K. Thallapally, J. Liu, Singlecrystal-to-single-crystal transformation in a one-dimensional Ag-Eu helical system, Inorg. Chem. 48 (2009) 6341–6343. [13](a) A. Cuevas, C. Kremer, M. Hummert, H. Schumann, F. Lloret, M. Julve, J. Faus, Magnetic properties and molecular structures of binuclear (2-pyrazinecarboxylate) 0bridged complexes containing Re(IV) and M(II) (M = Co, Ni), Dalton Trans. (2007) 342–350; (b) B. Masci, P. Thuéry, Pyrazinetetracarboxylic acid as an assembler ligand in uranyl-organic frameworks, Cryst. Growth Des. 8 (2008) 1689–1696. [14] T.F. Liu, J. Lü, L.X. Shi, Z.G. Guo, R. Cao, Conformation control of a flexible 1, 4-phenylenediacelate ligand in coordination complexes: a rigidity-modulated strategy, CrystEngComm 11 (2009) 583–588. [15](a) J. Zhu, X.H. Bu, P.Y. Feng, G.D. Stucky, An open-framework material with dangling organic functional groups in 24-ring channels, J. Am. Chem. Soc. 122 (2000) 11563–11564; (b) J.L. Song, J.G. Mao, Y.Q. Sun, A. Clearfield, Novel hybrid porous 3D networks lead(II) diphosphonate and triphosphonate containing 1, 3, 5-benzenetricarboxylate, Eur. J. Inorg. Chem. (2003) 4218–4226. [16] J.L. Song, C. Lei, J.G. Mao, Syntheses, crystal structures, and lumicescent properties of novel layered lanthanide sulfonate-phosphonates, Inorg. Chem. 43 (2004) 5630–5634. [17](a) C.H. Lin, K.H. Lii, Synthesis and characterization of the first organically templated metal oxalatophosphonate: (C3H12N2)0.5[Ga3(C2O4)(CH3PO3)4]·0.5H2O, Inorg. Chem. 43 (2004) 6403–6407; (b) N. Stock, G.D. Stucky, A.K. Cheetham, The hybrid open-framework of tin(II) phosphopropionate oxalate, Sn4(O3PCH2CH2CO2)2(C2O4), Chem. Commun. (2000) 2277–2278. [18](a) M.H. Zeng, S. Hu, Q. Chen, G. Xie, Q. Shuai, S.L. Gao, L.Y. Tang, Apical ligand substitution, shape recognition, vapor-adsorption phenomenon, and microcalorimetry for a pillared bilayer porous framework that shrinks or expands in crystal-to-crystal manners upon change in the cobalt(II) coordination environment, Inorg. Chem. 48 (2009) 7070–7079; (b) D. Sarmat, K.V. Ramanujachary, S.E. Lofland, T. Magdaleno, S. Natarajan, Amino acid based MOFs: synthesis, structures, single crystal to single crystal transformation, magnetic and related studies in a family of cobalt and nickel aminoisophthales, Inorg. Chem. 48 (2009) 11660–11676; (c) K.O. Kongshaug, H. Fjellvåg, Design of novel bilayer compounds of the CPO-8type containing 1D channels, Inorg. Chem. 45 (2006) 2424–2429; (d) H. Furukawa, J. Kim, N.W. Ockwig, M. O'Keeffe, O.M. Yaghi, Control of vertex geometry, structure dimensionality, functionality, and pore metrics in the reticular synthesis of crystalline metal-organic frameworks and polyhedra, J. Am. Chem. Soc. 130 (2008) 11650–11661;

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(e) Y.C. Qiu, H. Deng, S.H. Yang, J.X. Mou, C. Daiguebonne, N. Kerbellec, O. Guillou, S.R. Batten, Inorg. Chem. 48 (2009) 3976–3981; (f) Q. Gao, M.Y. Wu, Y.G. Huang, L. Chen, W. Wei, Q.F. Zhang, F.L. Jiang, M.C. Hong, Double-walled tubular metal-organic frameworks constructed from bi- strand helices, CrystEngComm 11 (2009) 1831–1833. [19] C. N. R. Rao, S. Natarajan, R. Vaidhyanathan, Metal carboxylates with open architectures, Angew. Chem., Int. Ed. 43 (2004) 1466–1496. [20] Synthesis of complexes 1–7: A mixture of 5-aminoisophthalic acid (0.0905 g, 0.5 mmol), Ln(NO3)3·6H2O(0.135 g, 0.3 mmol), H2C2O4·2H2O(0.0378 g, 0.3 mmol), and 10.0 ml deionized water were sealed in a 23.0 mL Teflon-lined stainless-steel autoclave and heated to 160 °C for 3 days then cooled to room temperature at 5 °C/h. Block-shaped crystals were obtained. 1: Anal. Calcd for C10H8CeNO9: C, 28.15; H, 1.88; N, 3.28; found: C, 28.13; H, 1.90; N, 3.29. IR data (KBr, cm−1): 3408(vs), 2928(w), 2367(w), 2333(w), 1631(vs), 1573(w), 1429(w), 1373(s), 1315(m), 1151(s), 1092(s), 893(w), 789(w), 707(w). 2: Anal. Calcd for C10H8PrNO9: C, 28.10; H, 1.87; N, 3.28; found: C, 28.15; H, 1.89; N, 3.25. IR data (KBr, cm−1): 3420(s), 2928(m), 2379(w), 1619(vs), 1573(s), 1453(w), 1385(vs), 1315(m), 1163(s), 1093(s), 893(w), 789(w), 707(w). 3: Anal. Calcd for C10H8NdNO9: C10H8NdNO9 (430.41): C, 27.88; H, 1.86; N, 3.25; found: C, 27.90; H, 1.85; N, 3.21. IR data (KBr, cm−1): 3420(vs), 2369(s), 1631(s), 1385(vs), 1139(s), 859(w), 789(w). 4: Anal. Calcd for C10H8SmNO9: C, 27.49; H, 1.83; N, 3.21; found: C, 27.52; H, 1.85; N, 3.24. IR data (KBr, cm−1): 3387(m), 3241(m), 2930(m), 1619(vs), 1516(w), 1392(s), 1319(m), 1141(s), 922(w), 787(m), 715(w). 5: Anal. Calcd for C10H8EuNO9: C, 27.39; H, 1.83; N, 3.20; found: C, 27.42; H, 1.86; N, 3.23. IR data (KBr, cm−1): 2920(m), 2577(m), 1599(s),, 1392(vs), 1319(w), 1152(s), 882(w), 787(w),715(w). 6: Anal. Calcd for C10H8GdNO9: C, 27.06; H, 1.80; N, 3.16; found: C, 27.01; H, 1.78; N, 3.12. IR data (KBr, cm−1): 3408(m),, 2928(w), 2367(w), 1631(s), 1385(m), 1315(m), 1151(s), 1093(s), 881(w), 789(w), 707(w). 7: C, 26.96; H, 1.80; N, 3.15; found: C, 26.99; H, 1.82; N, 3.12. IR data (KBr, cm−1): 3426(w), 2930(m), 2586(w), 1599(vs), 1516(m), 1475(w), 1381(vs), 1317(s), 1152(s), 1036(w), 93(w), 787(m), 715(w). Synthesis of complexes 8–11: A mixture of 5-aminoisophthalic acid (0.0905 g, 0.5 mmol), Ln2O3(0.105 g, 0.3 mmol), H2C2O4·2H2O(0.0378 g, 0.3 mmol), and 10.0 ml deionized water were sealed in a 23.0 mL Teflon-lined stainless-steel autoclave and heated to 160 °C for 3 days then cooled to room temperature at 5 °C/h. Block-shaped crystals were obtained. 8: Anal. Calcd for C18H16Dy2N2O15: C, 26.17; H, 1.94; N, 3.39; found: C, 26.18; H, 1.92; N, 3.40. IR data (KBr, cm−1): 3413(s), 2372(m), 1616(m), 1521(m), 1379(vs), 1143(vs), 987(w), 799(w), 716(w). 9: Anal. Calcd for C18H16Ho2N2O15: C, 26.02; H, 1.93; N, 3.37; found: C, 26.00; H, 1.95; N, 3.34. IR data (KBr, cm−1): 3425(s), 2928(m), 2372(w), 1626(vs), 1555(s), 1377(s), 1321(m), 1153(vs), 989(w), 882(w), 787(w), 716(w). 10: Anal. Calcd for C18H16Er2N2O15: C, 26.96; H, 1.80; N, 3.15; found: C, 26.98; H, 1.82; N, 3.15. IR data (KBr, cm−1): 3427(s), 2926(m), 2371(w), 1620(vs), 1531(vs), 1378(s), 1150(s), 986(w), 880(w), 715(w). 11: Anal. Calcd for C18H16Tm2N2O15: C, 25.87; H, 1.92; N, 3.35; found: C, 25.86; H, 1.93; N, 3.36. IR data (KBr, cm−1): 3401(s), 2360(m), 1650(s), 1533(s), 1450(s), 1307(m), 1153(s), 1082(s), 882(w), 799(w). [21] Crystal data for complex 1: Monoclinic, C 2/c, a =20.131(2) Å, b=9.6911(10) Å, c=13.7382(15), β=117.6020(10) ° V=2375.2(4) Å3, Z=8, Dc=2.384, F(000) = 1640.0, GOF=1.117, R1(I>2σ(I))=0.0202, and wR2 (all data)=0.0506. 2: Monoclinic, C 2/c, a=20.0923(19) Å, b=9.6520(9) Å, c=13.7184(13), β=117.6930(10) ° V=2355.7(4) Å3, Z=8, Dc=2.408, F(000) =1648.0, GOF=1.449, R1(I>2σ(I))= 0.0267, and wR2 (all data)=0.0501. 3: Monoclinic, C 2/c, a=20.0750(16) Å, b=9.6082(8) Å, c=13.6929(11) Å, β=117.7910(10) ° V=2336.5(3) Å3, Z=8, Dc=2.447, F(000) =1656.0, GOF=1.048, R1(I>2σ(I))=0.0431, and wR2 (all data)=0.0451. 4: Monoclinic, C 2/c, a=20.033(2) Å, b=9.5239(11) Å, c= 13.6374(15) Å, β=117.9940(10) ° V=2284.5(7) Å3, Z=8, Dc=2.579, F(000)= 1696.0, GOF=1.100, R1(I>2σ(I))=0.0349, and wR2 (all data)=0.0959. 5: Monoclinic, C 2/c, a=20.0291(18) Å, b=9.5076(9) Å, c=13.6558(12) Å, β=118.0960(10) ° V=2266.0(6) Å3, Z=8, Dc=2.609, F(000) =1672.0, GOF=1.198, R1(I>2σ(I))= 0.0272, and wR2 (all data)=0.0724. 6: Monoclinic, C 2/c, a=20.028(4) Å, b=9.4862(17) Å, c=13.641(2) Å, β=118.179(2) ° V=2297.5(4) Å3, Z=8, Dc= 2.524, F(000)=1680.0, GOF=1.078, R1(I>2σ(I))=0.0208, and wR2 (all data)= 0.0525. 7: Monoclinic, C 2/c, a=19.992(3) Å, b=9.4432(15) Å, c=13.634(2) Å, β=118.313(2) ° V=2294.0(4) Å3, Z=8, Dc=2.537, F(000)=1680.0, GOF=1.042, R1(I>2σ(I))=0.0237, and wR2 (all data)=0.0538. 8: Orthorhombic, P n n a, a=15.323(3) Å, b=14.216(3) Å, c=11.020(2) Å, V=2400.4(8) Å3, Z=4, Dc= 2.284, F(000)=1560.0, GOF=1.101, R1(I>2σ(I))=0.0456, and wR2 (all data)= 0.1128. 9: Orthorhombic, P n n a, a=15.323(3) Å, b=14.216(3) Å, c=11.020(2) Å, V=2400.4(8) Å3, Z=4, Dc=2.297, F(000)=1568.0, GOF=1.0730., R1(I>2σ(I))= 0525, and wR2 (all data)=0.1478. 10: Orthorhombic, P n n a, a=15.323(3) Å, b=14.216(3) Å, c=11.020(2) Å, V=2400.4(8) Å3, Z=4, Dc=2.310, F(000)= 1576.0, GOF=1.066., R1(I>2σ(I))=0.0396, and wR2 (all data)=0.1190. 11: Orthorhombic, P n n a, a=15.2398(15) Å, b=14.1399(13) Å, c=10.9549(10) Å, V=2360.7(4) Å3, Z=4, Dc=2.358, F(000)=1584.0, GOF=1.082., R1(I>2σ(I))= 0.0313, and wR2 (all data)=0.0885. [22](a) A.F. Wells, Three-dimensional nets and polyhedra, Wiley, New York, 1977.; (b) V.A. Blatov, http://www.topos.ssu.samara.ru/starting.html2006. [23](a) F.S. Richardson, Terbium (III) and europium (III) ions as luminescent probes and stains for biomolecular systems, Chem. Rev. 82 (1982) 541–552; (b) X.J. Gu, D.F. Xue, Spontaneously resolved homochiral 3D lanthanide-silver heterometallic coordination framework with extended helical Ln-O-Ag subunits, Inorg. Chem. 45 (2006) 9257–9261.