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A novel Eu(III) –Ag(I) heterometallic coordination polymer based on planar hexanuclear heterometallic second building unit
Inorganic Chemistry Communications 50 (2014) 75–78
Contents lists available at ScienceDirect
Inorganic Chemistry Communications journal homepage: www.elsevier.com/locate/inoche
A novel Eu(III) –Ag(I) heterometallic coordination polymer based on planar hexanuclear heterometallic second building unit Tian-Tian Li a, Yuan-yuan Tian b, Rong-Hua Zeng b,⁎, Sheng-Run Zheng b,⁎ a b
GuiYang College of Traditional Chinese Medicine, Guiyang 550000, PR China Institute of Special Materials & 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 22 July 2014 Received in revised form 6 October 2014 Accepted 9 October 2014 Available online 13 October 2014
a b s t r a c t A novel Eu(III)–Ag(I) coordination polymer [Eu2Ag(μ4-oPyIDC)2(NO3)(H2O)]n (H3oPyIDC = 2-(pyridine-3-yl)1H-imidzole-4,5-dicarboxylate, 1) was formed based on a planar hexanuclear heterometallic Eu4Ag2 secondary building unit. The planar hexanuclear secondary building blocks are interconnected to a 3D framework with pcu topology. The luminescence property of compound 1 is also investigated. © 2014 Elsevier B.V. All rights reserved.
Keywords: Heterometallic CP Planar hexanuclear SBU Luminescence property
Over the past decade, the rational design and construction of heterometallic coordination polymers (CPs) have attracted much interest, not only because of their impressive structural diversity in architecture and topology, but also because of their potential application in magnetism, luminescence, adsorption, and ion-exchange [1–5]. The rational design and construction of heterometallic CPs, especially three-dimensional (3D) d–f heterometallic CPs, remain a challenge for chemists [6]. A greater balance is needed between the adaptabilities of building blocks to construct heterometallic CPs [7]. The use of heterometallic secondary building blocks (SBUs) is an effective strategy for constructing heterometallic CPs; many heterometallic CPs have indeed been obtained using the present strategy [8]. Mostly reported heterometallic SBUs lack well-defined geometries, and welldefined planar polynuclear heterometallic SBUs still rarely construct heterometallic CPs. Introducing an additional group to the 2-position of imidazole-4,5dicarboxylic acid (H3IDC) in the chemistry of imidazole-based dicarboxylate ligands is gaining interest. Presently, only some imidazole-based dicarboxylate ligands with different substituted groups, such as methyl [9], propyl [10], hydroxymethyl [11], pmethylphenyl [12], pyridyl [13], or 3,4-dimethylphenyl [14], have been designed and studied extensively. We investigate the coordination chemistry of 2-(pyridine-3-yl)-1H-imidzole-4,5-dicarboxylate
⁎ Corresponding authors. E-mail addresses: [email protected] (R.-H. Zeng), [email protected] (S.-R. Zheng).
http://dx.doi.org/10.1016/j.inoche.2014.10.006 1387-7003/© 2014 Elsevier B.V. All rights reserved.
(H3mPyIDC) and 2-(pyridine-4-yl)-1H-imidzole-4,5-dicarboxylate (H3pPyIDC) [13b–d]. These ligands tend to form planar SBU [13c,d] and heterometallic CPs [13b] in previous studies. Inspired by the results, we change pyridine-3-yl/pyridine-4-yl group to pyridine-2-yl group in the current work; thus, a heterometallic CP based on planar SBU [Eu2Ag(μ4-oPyIDC)2(NO3)(H2O)]n (1) was obtained. To the best of our knowledge, only limited CPs constructed from H3oPyIDC have been reported, including several Cd(II), Pb(II), and two Ni(II) CPs [13a]. Additionally, compound 1 is the first heterometallic CP based on H3oPyIDC. Compound 1 was prepared by hydrothermal reaction of Eu2O3, H3oPyIDC, and AgNO3 at 160 °C for 4 days. Single crystal X-ray diffraction revealed that compound 1 crystallizes in a monoclinic system with C2/c space group. As shown in Fig. 1a, the asymmetric unit of 1 contains one Eu(III) ion, one Ag(I) with 1/2 site occupancy, one oPyIDC3− anion, and half of a coordination water molecule or half of a coordinated NO− 3 anion. Seven coordinated Eu(III) ion sites are occupied by five O atoms and two N atoms from three different oPyIDC3 − anions. The remaining coordinated Eu(III) site is randomly occupied by coordination water molecule or NO− 3 anion. The overall ratio of water molecule and NO− 3 anion is about 1/1, as deduced from the charge balance requirement and element analysis data. The Eu(III)–O and Eu(III)–N bond distances are 2.286(2)–2.594(5) and 2.414(2)– 2.9495(12) Å, respectively [15]. The Ag(I) ion shows a distorted tetrahedral geometry with two N atoms and two O atoms from two different oPyIDC3− anions. The bond length of Ag–N is 2.117(2) Å is within the range of observations for other Ag(I) compounds with imidazolebased dicarboxylate ligands [13c].
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Fig. 1. (a) The coordination environment of Eu(III) and Ag(I) in 1. (b) The top view and side view of the hexanuclear planar SBU in 1.
The oPyIDC3− ligand adopts a μ4-kN,O:kO,O′:kO′,O″:kO″,N′,N″ coordination mode to simultaneously bridge to three Eu(III) ions in two bis-O,O-chelating and one tri-N,N,O-chelating and one Ag(I) ion in bis-
N,O-chelating fashion, as illustrated in Scheme 1. The greatest difference between oPyIDC3− and mPyIDC3−/pPyIDC3− ligands is the introduction of o-pyridyl group bringing a tri-chelating coordination site to the oPyIDC3− ligand, which is selectively coordinated to larger Eu(III) ion due to the larger binding angle. Therefore, based on the abovementioned coordination mode of oPyIDC3 − ligand, four Eu(III) ions and two Ag(I) ions are combined by two μ4-oPyIDC3− ligands to produce a heterometallic hexanuclear [Eu4Ag2(oPyIDC)2] SBU, as shown in Fig. 1b. Such SBU differs from planar SBUs based on mPyIDC3−/pPyIDC3− (in which the number of Ln(III) and Ag(I) atoms are 2 and 4, respectively), illustrated in Scheme 1. The mean plane deviation in SBU of four Eu(III) ions and two Ag(I) ions is 2.3212(11), indicating that they are nearly on the same plane (Fig. 1b). Additionally, because of the tri-chelating coordination, the pyridyl ring is also almost coplanar to the plane, in contrast to that observed in compounds with mPyIDC3− or pPyIDC3− ligands [13]. Adjacent nonbonding Eu⋯Eu distances (separated by carboxyl groups) are 4.0657(22) and 6.7739(19) Å, while the neighboring nonbonding Eu⋯Ag length (that separated by carboxyl groups) is 5.0010(21) Å. Each hexanuclear SBU is bound to four other SBUs via shared Eu(III) ions, giving rise to a 2D layer extending along the bc plane (Fig. 2a). The angle between two adjacent SBUs shared by Eu(III) ion is 78° (Fig. 2b). The 2D network is further connected by shared Ag(I) ions to a 3D framework (Fig. 2c). The angle between two adjacent SBUs shared by Ag(I) ion is 78° (Fig. 2d). In the 3D framework, the 2D Eu(III) layer packs along a direction in abab fashion. To better understand the structure of compound 1 and identify the complicated connectivity between SBUs, the network topology of 2 is further analyzed. Fig. 2c shows that each SBU connects to another 6 SBUs, seen as 6-connected nodes (Fig. S1a) and creates a 6-connected pcu framework, as shown in Fig. S1b. Powder XRD pattern of compound 1 is in good agreement with simulated patterns generated from single-crystal diffraction data, indicating that single phase compound 1 is formed (Fig. S2). Due to the excellent luminescent properties of Eu(III) ions in the visible region [16–18], the photoluminescence of 1 in solid state was investigated at room temperature. As shown in Fig. 3, the emission spectrum of complex 1 displays the characteristic f–f transition of Eu(III) ion upon excitation at 348 nm, implying that ligand-to-europium energy transfer is efficient under experimental conditions. The emission spectrum is dominated by the characteristic 5D0 → 7F2 electron dipole transition at 616 nm. Additionally, two weak peaks at 653 nm and 704 nm can be attributed to the 5D0 → 7F3 and 5D0 → 7F4 transitions, respectively [16–18]. In summary, a Eu(III)–Ag(I) heterometallic CP based on a rare hexanuclear planar Eu4Ag2 SBUs is synthesized. Structural analysis reveals that SBUs are effectively interconnected by shared Eu(III) and Ag(I) ions to a 3D framework. The present work indicates that the structural motif of an imidazole dicarboxylate ligand is suitable for constructing heterometallic CPs based on heterometallic planar SBUs.
Acknowledgment This work was financially supported by the National Natural Science Foundation of China (Grant 21473062 and 21171059).
Appendix A. Supplementary material
Scheme 1. The coordination mode of oPyIDC3−, the formation of the hexanuclear planar SBUs based on oPyIDC3− and mPyIDC3−/pPyIDC3−.
CCDC 1014494 contains the supplementary crystallographic data for the compound 1. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/ data_request/cif. Supplementary data associated with this article can be found in the section of supporting information at http://dx.doi.org/ 10.1016/j.inoche.2014.10.006.
T.-T. Li et al. / Inorganic Chemistry Communications 50 (2014) 75–78
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Fig. 2. (a) The 2D network in 1. (b) The two adjacent hexanuclear planar SBUs interconnected by Eu(III) ions. (c) The 3D network in 1. (d) The two adjacent hexanuclear planar SBUs interconnected by Ag(I) ion.
[4]
[5]
[6]
Fig. 3. Solid-state emission spectrum of compound 1.
[7]
References [1] (a) M. Sakamoto, K. Manseki, H. Okawa, d–f heteronuclear complexes: synthesis, structures and physicochemical aspects, Coord. Chem. Rev. 219−221 (2001) 379–414; (b) C. Aronica, G. Pilet, G. Chastanet, W. Wernsdorfer, J.F. Jacquot, D.A. Luneau, Nonanuclear dysprosium(III)–copper(II) complex exhibiting single-molecule magnet behavior with very slow zero-field relaxation, Angew. Chem. Int. Ed. 45 (2006) 4659–4662; (c) T.K. Prasad, M.V. Rajasekharan, J.P. Costes, A cubic 3d–4f structure with only ferromagnetic Gd–Mn interactions, Angew. Chem. Int. Ed. 46 (2007) 2851–2854; (d) M. Nippe, J.F. Wang, E. Bill, H. Hope, N.S. Dalal, J.F. Berry, Crystals in which some metal atoms are more equal than others: inequalities from crystal packing and their spectroscopic/magnetic consequences, J. Am. Chem. Soc. 132 (2010) 14261–14272. [2] (a) C. Yan, K. Li, S.C. Wei, H.P. Wang, L. Fu, M. Pan, C.Y. Su, Lanthanide homometallic and d–f heterometallic MOFs from the same tripodal ligand: structural comparison, one photon (OP) vs. two photon(TP) luminescence and selective guest adsorption behavior, J. Mater. Chem. 22 (2012) 9846–9852; (b) Y.J. Cui, Y.F. Yue, G.D. Qian, B.L. Chen, Luminescent functional metal–organic frameworks, Chem. Rev. 112 (2012) 1126–1162. [3] (a) B. Zhao, P. Cheng, X.Y. Chen, C. Cheng, W. Shi, D.Z. Liao, S.P. Yan, Z.H. Jiang, Design and synthesis of 3d–4f metal-based zeolite-type materials with a 3D
[8]
[9]
[10]
[11]
nanotubular structure encapsulated “water” pipe, J. Am. Chem. Soc. 126 (2004) 3012–3013; (b) C.J. Li, Z.J. Lin, M.X. Peng, J.D. Leng, M.M. Yang, M.L. Tong, Novel threedimensional 3d–4f microporous magnets exhibiting selective gas adsorption behavior, Chem. Commun. (2008) 6348–6350; (c) P. Mahata, K.V. Ramya, S. Natarajan, Reversible water intercalation accompanied by coordination and color changes in a layered metal–organic framework, Inorg. Chem. 48 (2009) 4942–4944. (a) S.G. Shore, E.R. Ding, C. Park, M.A. Keane, Vapor phase hydrogenation of phenol over silica supported Pd and Pd@Yb catalysts, Catal. Commun. 3 (2002) 77–84; (b) V. Gnanadesikan, S. Matsunaga, M. Shibasaki, Heterobimetallic transition metal/ rare earth metal bifunctional catalysis: a Cu/Sm/Schiff base complex for synselective catalytic asymmetric nitro-Mannich reaction, J. Am. Chem. Soc. 132 (2010) 4925–4934. 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 iondependent photoinduced emission spectra, J. Am. Chem. Soc. 129 (2007) 10620–10621. (a) G. Novitchi, W. Wernsdorfer, L.F. Chibotaru, J.P. Costes, C.E. Anson, A.K. Powell, Supramolecular “double-propeller” dimers of hexanuclear Cu(II)/Ln(III) complexes: a {Cu3Dy3}2 single-molecule magnet, Angew. Chem. Int. Ed. 48 (2009) 1614–1619; (b) T.C. Stamatatos, S.J. Teat, W. Wernsdorfer, G. Christou, Enhancing the quantum properties of manganese–lanthanide single-molecule magnets: observation of quantum tunneling steps in the hysteresis loops of a {Mn12Gd} cluster, Angew. Chem. Int. Ed. 48 (2009) 521–524. S.L. Cai, S.R. Zheng, Z.Z. Wen, J. Fan, N. Wang, W.G. Zhang, Two types of new threedimensional d–f heterometallic coordination polymers based on 2-(pyridin-3-yl)1H-imidazole-4,5-dicarboxylate and oxalate ligands: syntheses, structures, luminescence, and magnetic properties, Cryst. Growth Des. 12 (2012) 4441–4449. R.L. Chen, X.Y. Chen, S.R. Zheng, J. Fan, W.G. Zhang, Construction of Ag(I)–Ln(III) heterometallic coordination polymers based on binuclear Ag2(DSPT)2 (H2DSPT = 4′-(2,4-disulfophenyl)-2,2′:6′2″-terpyridine) rings and Ln(III) dimeric molecular building blocks, Cryst. Growth Des. 13 (2013) 4428–4434. X. Feng, L.F. Ma, L. Liu, L.Y. Wang, H.L. Song, S.Y. Xie, A series of heterometallic threedimensional frameworks constructed from imidazole-dicarboxylate: structures, luminescence, and magnetic properties, Cryst. Growth Des. 13 (2013) 4469–4479. J.H. Deng, D.C. Zhong, X.Z. Luo, H.J. Liu, T.B. Lu, 2-Propyl-4,5-dicarboxylate-imidazole (H3PIDC) based cadmium(II) coordination compounds stabilized by supramolecular interactions: from mononuclear and tetranuclear oligomers to one-dimensional (1D) chain and two-dimensional (2D) layer polymers, Cryst. Growth Des. 12 (2012) 4861–4869. (a) S.L. Cai, S.R. Zheng, Z.Z. Wen, J. Fan, W.G. Zhang, Construction of Ba(II) coordination polymers based on imidazole-based dicarboxylate ligands: structural diversity tuned by alcohol solvents, Cryst. Growth Des. 12 (2012) 3575–3582; (b) S.R. Zheng, S.L. Cai, J. Fan, T.T. Xiao, W.G. Zhang, Three new complexes synthesized from an imidazole-based dicarboxylate ligand containing hydroxymethyl group, Inorg. Chem. Commun. 14 (2011) 1097–1101; (c) S.R. Zheng, S.L. Cai, M. Pan, J. Fan, T.T. Xiao, W.G. Zhang, The construction of coordination networks based on imidazole-based dicarboxylate ligand containing hydroxymethyl group, CrystEngComm 13 (2011) 883–888.
78
T.-T. Li et al. / Inorganic Chemistry Communications 50 (2014) 75–78
[12] Y. Zhang, P. Yuan, Y. Zhu, G. Li, Syntheses, crystal structures and thermal properties of six coordination polymers based on 2-(p-methylphenyl)-imidazole dicarboxylate, Dalton Trans. 42 (2013) 14776–14785. [13] (a) X. Zheng, Y. Huang, J. Duan, C. Wang, L. Wen, J. Zhao, D. Li, A microporous Zn(II)-MOF with open metal sites: structure and selective adsorption properties, Dalton Trans. 43 (2014) 8311–8317; (b) S.L. Cai, S.R. Zheng, Z.Z. Wen, J. Fan, W.G. Zhang, Construction of luminescent three-dimensional Ln(III)–Zn(II) heterometallic coordination polymers based on 2-pyridyl imidazole dicarboxylate, CrystEngComm 14 (2012) 8236–8243; (c) S.L. Cai, S.R. Zheng, Z.Z. Wen, J. Fan, W.G. Zhang, A series of new threedimensional d–f heterometallic coordination polymers with rare 10-connected bct net topology based on planar hexanuclear heterometallic second building units, Cryst. Growth Des. 12 (2012) 5737–5745; (d) S.L. Cai, S.R. Zheng, M. Pan, J.B. Tan, J. Fan, W.G. Zhang, An unprecedented (3,4,14)-connected 3D metal–organic framework based on planar octanuclear lead(II) clusters as a secondary building unit, CrystEngComm 14 (2012) 1193–1196. [14] (a) H. Jia, Y. Li, Z. Xiong, C. Wang, G. Li, Five metal–organic frameworks from 3,4dimethylphenyl substituted imidazole dicarboxylate: syntheses, structures and properties, Dalton Trans. 43 (2014) 3704–3715;
[15]
[16]
[17]
[18]
(b) C. Wang, T. Wang, W. Zhang, H. Lu, G. Li, Two unprecedented transition-metal– organic frameworks showing one dimensional–hexagonal channel open network and two-dimensional sheet structures, Cryst. Growth Des. 12 (2012) 1091–1094. Z.L. Fang, S.R. Zheng, J. Fan, W.G. Zhang, In situ synthesis of a zwitterionic ligand and formation of a Eu(III) coordination polymer with double-bridged connectors, Inorg. Chem. Commun. 20 (2012) 122–125. S. Quici, M. Cavazzini, G. Marzanni, G. Accorsi, N. Armaroli, B. Ventura, F. Barigellett, Visible and near-infrared intense luminescence from water-soluble lanthanide [Tb(III), Eu(III), Sm(III), Dy(III), Pr(III), Ho(III), Yb(III), Nd(III), Er(III)] complexes, Inorg. Chem. 44 (2005) 529–537. F. Luo, Y. Che, J. Zheng, Employing La2-(La = Eu, Tb, Pr) or Co3-based molecule building blocks to construct 3,8-connected nets: hydrothermal synthesis, structure, luminescence, and magnetic properties, Cryst. Growth Des. 8 (2008) 2006–2010. M.S. Liu, Q.Y. Yu, Y.P. Cai, C.Y. Su, X.M. Lin, X.X. Zhou, J.W. Cai, One-, two-, and threedimensional lanthanide complexes constructed from pyridine-2,6-dicarboxylic acid and oxalic acid ligands, Cryst. Growth Des. 8 (2008) 4083–4091.
Contents lists available at ScienceDirect
Inorganic Chemistry Communications journal homepage: www.elsevier.com/locate/inoche
A novel Eu(III) –Ag(I) heterometallic coordination polymer based on planar hexanuclear heterometallic second building unit Tian-Tian Li a, Yuan-yuan Tian b, Rong-Hua Zeng b,⁎, Sheng-Run Zheng b,⁎ a b
GuiYang College of Traditional Chinese Medicine, Guiyang 550000, PR China Institute of Special Materials & 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 22 July 2014 Received in revised form 6 October 2014 Accepted 9 October 2014 Available online 13 October 2014
a b s t r a c t A novel Eu(III)–Ag(I) coordination polymer [Eu2Ag(μ4-oPyIDC)2(NO3)(H2O)]n (H3oPyIDC = 2-(pyridine-3-yl)1H-imidzole-4,5-dicarboxylate, 1) was formed based on a planar hexanuclear heterometallic Eu4Ag2 secondary building unit. The planar hexanuclear secondary building blocks are interconnected to a 3D framework with pcu topology. The luminescence property of compound 1 is also investigated. © 2014 Elsevier B.V. All rights reserved.
Keywords: Heterometallic CP Planar hexanuclear SBU Luminescence property
Over the past decade, the rational design and construction of heterometallic coordination polymers (CPs) have attracted much interest, not only because of their impressive structural diversity in architecture and topology, but also because of their potential application in magnetism, luminescence, adsorption, and ion-exchange [1–5]. The rational design and construction of heterometallic CPs, especially three-dimensional (3D) d–f heterometallic CPs, remain a challenge for chemists [6]. A greater balance is needed between the adaptabilities of building blocks to construct heterometallic CPs [7]. The use of heterometallic secondary building blocks (SBUs) is an effective strategy for constructing heterometallic CPs; many heterometallic CPs have indeed been obtained using the present strategy [8]. Mostly reported heterometallic SBUs lack well-defined geometries, and welldefined planar polynuclear heterometallic SBUs still rarely construct heterometallic CPs. Introducing an additional group to the 2-position of imidazole-4,5dicarboxylic acid (H3IDC) in the chemistry of imidazole-based dicarboxylate ligands is gaining interest. Presently, only some imidazole-based dicarboxylate ligands with different substituted groups, such as methyl [9], propyl [10], hydroxymethyl [11], pmethylphenyl [12], pyridyl [13], or 3,4-dimethylphenyl [14], have been designed and studied extensively. We investigate the coordination chemistry of 2-(pyridine-3-yl)-1H-imidzole-4,5-dicarboxylate
⁎ Corresponding authors. E-mail addresses: [email protected] (R.-H. Zeng), [email protected] (S.-R. Zheng).
http://dx.doi.org/10.1016/j.inoche.2014.10.006 1387-7003/© 2014 Elsevier B.V. All rights reserved.
(H3mPyIDC) and 2-(pyridine-4-yl)-1H-imidzole-4,5-dicarboxylate (H3pPyIDC) [13b–d]. These ligands tend to form planar SBU [13c,d] and heterometallic CPs [13b] in previous studies. Inspired by the results, we change pyridine-3-yl/pyridine-4-yl group to pyridine-2-yl group in the current work; thus, a heterometallic CP based on planar SBU [Eu2Ag(μ4-oPyIDC)2(NO3)(H2O)]n (1) was obtained. To the best of our knowledge, only limited CPs constructed from H3oPyIDC have been reported, including several Cd(II), Pb(II), and two Ni(II) CPs [13a]. Additionally, compound 1 is the first heterometallic CP based on H3oPyIDC. Compound 1 was prepared by hydrothermal reaction of Eu2O3, H3oPyIDC, and AgNO3 at 160 °C for 4 days. Single crystal X-ray diffraction revealed that compound 1 crystallizes in a monoclinic system with C2/c space group. As shown in Fig. 1a, the asymmetric unit of 1 contains one Eu(III) ion, one Ag(I) with 1/2 site occupancy, one oPyIDC3− anion, and half of a coordination water molecule or half of a coordinated NO− 3 anion. Seven coordinated Eu(III) ion sites are occupied by five O atoms and two N atoms from three different oPyIDC3 − anions. The remaining coordinated Eu(III) site is randomly occupied by coordination water molecule or NO− 3 anion. The overall ratio of water molecule and NO− 3 anion is about 1/1, as deduced from the charge balance requirement and element analysis data. The Eu(III)–O and Eu(III)–N bond distances are 2.286(2)–2.594(5) and 2.414(2)– 2.9495(12) Å, respectively [15]. The Ag(I) ion shows a distorted tetrahedral geometry with two N atoms and two O atoms from two different oPyIDC3− anions. The bond length of Ag–N is 2.117(2) Å is within the range of observations for other Ag(I) compounds with imidazolebased dicarboxylate ligands [13c].
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Fig. 1. (a) The coordination environment of Eu(III) and Ag(I) in 1. (b) The top view and side view of the hexanuclear planar SBU in 1.
The oPyIDC3− ligand adopts a μ4-kN,O:kO,O′:kO′,O″:kO″,N′,N″ coordination mode to simultaneously bridge to three Eu(III) ions in two bis-O,O-chelating and one tri-N,N,O-chelating and one Ag(I) ion in bis-
N,O-chelating fashion, as illustrated in Scheme 1. The greatest difference between oPyIDC3− and mPyIDC3−/pPyIDC3− ligands is the introduction of o-pyridyl group bringing a tri-chelating coordination site to the oPyIDC3− ligand, which is selectively coordinated to larger Eu(III) ion due to the larger binding angle. Therefore, based on the abovementioned coordination mode of oPyIDC3 − ligand, four Eu(III) ions and two Ag(I) ions are combined by two μ4-oPyIDC3− ligands to produce a heterometallic hexanuclear [Eu4Ag2(oPyIDC)2] SBU, as shown in Fig. 1b. Such SBU differs from planar SBUs based on mPyIDC3−/pPyIDC3− (in which the number of Ln(III) and Ag(I) atoms are 2 and 4, respectively), illustrated in Scheme 1. The mean plane deviation in SBU of four Eu(III) ions and two Ag(I) ions is 2.3212(11), indicating that they are nearly on the same plane (Fig. 1b). Additionally, because of the tri-chelating coordination, the pyridyl ring is also almost coplanar to the plane, in contrast to that observed in compounds with mPyIDC3− or pPyIDC3− ligands [13]. Adjacent nonbonding Eu⋯Eu distances (separated by carboxyl groups) are 4.0657(22) and 6.7739(19) Å, while the neighboring nonbonding Eu⋯Ag length (that separated by carboxyl groups) is 5.0010(21) Å. Each hexanuclear SBU is bound to four other SBUs via shared Eu(III) ions, giving rise to a 2D layer extending along the bc plane (Fig. 2a). The angle between two adjacent SBUs shared by Eu(III) ion is 78° (Fig. 2b). The 2D network is further connected by shared Ag(I) ions to a 3D framework (Fig. 2c). The angle between two adjacent SBUs shared by Ag(I) ion is 78° (Fig. 2d). In the 3D framework, the 2D Eu(III) layer packs along a direction in abab fashion. To better understand the structure of compound 1 and identify the complicated connectivity between SBUs, the network topology of 2 is further analyzed. Fig. 2c shows that each SBU connects to another 6 SBUs, seen as 6-connected nodes (Fig. S1a) and creates a 6-connected pcu framework, as shown in Fig. S1b. Powder XRD pattern of compound 1 is in good agreement with simulated patterns generated from single-crystal diffraction data, indicating that single phase compound 1 is formed (Fig. S2). Due to the excellent luminescent properties of Eu(III) ions in the visible region [16–18], the photoluminescence of 1 in solid state was investigated at room temperature. As shown in Fig. 3, the emission spectrum of complex 1 displays the characteristic f–f transition of Eu(III) ion upon excitation at 348 nm, implying that ligand-to-europium energy transfer is efficient under experimental conditions. The emission spectrum is dominated by the characteristic 5D0 → 7F2 electron dipole transition at 616 nm. Additionally, two weak peaks at 653 nm and 704 nm can be attributed to the 5D0 → 7F3 and 5D0 → 7F4 transitions, respectively [16–18]. In summary, a Eu(III)–Ag(I) heterometallic CP based on a rare hexanuclear planar Eu4Ag2 SBUs is synthesized. Structural analysis reveals that SBUs are effectively interconnected by shared Eu(III) and Ag(I) ions to a 3D framework. The present work indicates that the structural motif of an imidazole dicarboxylate ligand is suitable for constructing heterometallic CPs based on heterometallic planar SBUs.
Acknowledgment This work was financially supported by the National Natural Science Foundation of China (Grant 21473062 and 21171059).
Appendix A. Supplementary material
Scheme 1. The coordination mode of oPyIDC3−, the formation of the hexanuclear planar SBUs based on oPyIDC3− and mPyIDC3−/pPyIDC3−.
CCDC 1014494 contains the supplementary crystallographic data for the compound 1. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/ data_request/cif. Supplementary data associated with this article can be found in the section of supporting information at http://dx.doi.org/ 10.1016/j.inoche.2014.10.006.
T.-T. Li et al. / Inorganic Chemistry Communications 50 (2014) 75–78
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Fig. 2. (a) The 2D network in 1. (b) The two adjacent hexanuclear planar SBUs interconnected by Eu(III) ions. (c) The 3D network in 1. (d) The two adjacent hexanuclear planar SBUs interconnected by Ag(I) ion.
[4]
[5]
[6]
Fig. 3. Solid-state emission spectrum of compound 1.
[7]
References [1] (a) M. Sakamoto, K. Manseki, H. Okawa, d–f heteronuclear complexes: synthesis, structures and physicochemical aspects, Coord. Chem. Rev. 219−221 (2001) 379–414; (b) C. Aronica, G. Pilet, G. Chastanet, W. Wernsdorfer, J.F. Jacquot, D.A. Luneau, Nonanuclear dysprosium(III)–copper(II) complex exhibiting single-molecule magnet behavior with very slow zero-field relaxation, Angew. Chem. Int. Ed. 45 (2006) 4659–4662; (c) T.K. Prasad, M.V. Rajasekharan, J.P. Costes, A cubic 3d–4f structure with only ferromagnetic Gd–Mn interactions, Angew. Chem. Int. Ed. 46 (2007) 2851–2854; (d) M. Nippe, J.F. Wang, E. Bill, H. Hope, N.S. Dalal, J.F. Berry, Crystals in which some metal atoms are more equal than others: inequalities from crystal packing and their spectroscopic/magnetic consequences, J. Am. Chem. Soc. 132 (2010) 14261–14272. [2] (a) C. Yan, K. Li, S.C. Wei, H.P. Wang, L. Fu, M. Pan, C.Y. Su, Lanthanide homometallic and d–f heterometallic MOFs from the same tripodal ligand: structural comparison, one photon (OP) vs. two photon(TP) luminescence and selective guest adsorption behavior, J. Mater. Chem. 22 (2012) 9846–9852; (b) Y.J. Cui, Y.F. Yue, G.D. Qian, B.L. Chen, Luminescent functional metal–organic frameworks, Chem. Rev. 112 (2012) 1126–1162. [3] (a) B. Zhao, P. Cheng, X.Y. Chen, C. Cheng, W. Shi, D.Z. Liao, S.P. Yan, Z.H. Jiang, Design and synthesis of 3d–4f metal-based zeolite-type materials with a 3D
[8]
[9]
[10]
[11]
nanotubular structure encapsulated “water” pipe, J. Am. Chem. Soc. 126 (2004) 3012–3013; (b) C.J. Li, Z.J. Lin, M.X. Peng, J.D. Leng, M.M. Yang, M.L. Tong, Novel threedimensional 3d–4f microporous magnets exhibiting selective gas adsorption behavior, Chem. Commun. (2008) 6348–6350; (c) P. Mahata, K.V. Ramya, S. Natarajan, Reversible water intercalation accompanied by coordination and color changes in a layered metal–organic framework, Inorg. Chem. 48 (2009) 4942–4944. (a) S.G. Shore, E.R. Ding, C. Park, M.A. Keane, Vapor phase hydrogenation of phenol over silica supported Pd and Pd@Yb catalysts, Catal. Commun. 3 (2002) 77–84; (b) V. Gnanadesikan, S. Matsunaga, M. Shibasaki, Heterobimetallic transition metal/ rare earth metal bifunctional catalysis: a Cu/Sm/Schiff base complex for synselective catalytic asymmetric nitro-Mannich reaction, J. Am. Chem. Soc. 132 (2010) 4925–4934. 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 iondependent photoinduced emission spectra, J. Am. Chem. Soc. 129 (2007) 10620–10621. (a) G. Novitchi, W. Wernsdorfer, L.F. Chibotaru, J.P. Costes, C.E. Anson, A.K. Powell, Supramolecular “double-propeller” dimers of hexanuclear Cu(II)/Ln(III) complexes: a {Cu3Dy3}2 single-molecule magnet, Angew. Chem. Int. Ed. 48 (2009) 1614–1619; (b) T.C. Stamatatos, S.J. Teat, W. Wernsdorfer, G. Christou, Enhancing the quantum properties of manganese–lanthanide single-molecule magnets: observation of quantum tunneling steps in the hysteresis loops of a {Mn12Gd} cluster, Angew. Chem. Int. Ed. 48 (2009) 521–524. S.L. Cai, S.R. Zheng, Z.Z. Wen, J. Fan, N. Wang, W.G. Zhang, Two types of new threedimensional d–f heterometallic coordination polymers based on 2-(pyridin-3-yl)1H-imidazole-4,5-dicarboxylate and oxalate ligands: syntheses, structures, luminescence, and magnetic properties, Cryst. Growth Des. 12 (2012) 4441–4449. R.L. Chen, X.Y. Chen, S.R. Zheng, J. Fan, W.G. Zhang, Construction of Ag(I)–Ln(III) heterometallic coordination polymers based on binuclear Ag2(DSPT)2 (H2DSPT = 4′-(2,4-disulfophenyl)-2,2′:6′2″-terpyridine) rings and Ln(III) dimeric molecular building blocks, Cryst. Growth Des. 13 (2013) 4428–4434. X. Feng, L.F. Ma, L. Liu, L.Y. Wang, H.L. Song, S.Y. Xie, A series of heterometallic threedimensional frameworks constructed from imidazole-dicarboxylate: structures, luminescence, and magnetic properties, Cryst. Growth Des. 13 (2013) 4469–4479. J.H. Deng, D.C. Zhong, X.Z. Luo, H.J. Liu, T.B. Lu, 2-Propyl-4,5-dicarboxylate-imidazole (H3PIDC) based cadmium(II) coordination compounds stabilized by supramolecular interactions: from mononuclear and tetranuclear oligomers to one-dimensional (1D) chain and two-dimensional (2D) layer polymers, Cryst. Growth Des. 12 (2012) 4861–4869. (a) S.L. Cai, S.R. Zheng, Z.Z. Wen, J. Fan, W.G. Zhang, Construction of Ba(II) coordination polymers based on imidazole-based dicarboxylate ligands: structural diversity tuned by alcohol solvents, Cryst. Growth Des. 12 (2012) 3575–3582; (b) S.R. Zheng, S.L. Cai, J. Fan, T.T. Xiao, W.G. Zhang, Three new complexes synthesized from an imidazole-based dicarboxylate ligand containing hydroxymethyl group, Inorg. Chem. Commun. 14 (2011) 1097–1101; (c) S.R. Zheng, S.L. Cai, M. Pan, J. Fan, T.T. Xiao, W.G. Zhang, The construction of coordination networks based on imidazole-based dicarboxylate ligand containing hydroxymethyl group, CrystEngComm 13 (2011) 883–888.
78
T.-T. Li et al. / Inorganic Chemistry Communications 50 (2014) 75–78
[12] Y. Zhang, P. Yuan, Y. Zhu, G. Li, Syntheses, crystal structures and thermal properties of six coordination polymers based on 2-(p-methylphenyl)-imidazole dicarboxylate, Dalton Trans. 42 (2013) 14776–14785. [13] (a) X. Zheng, Y. Huang, J. Duan, C. Wang, L. Wen, J. Zhao, D. Li, A microporous Zn(II)-MOF with open metal sites: structure and selective adsorption properties, Dalton Trans. 43 (2014) 8311–8317; (b) S.L. Cai, S.R. Zheng, Z.Z. Wen, J. Fan, W.G. Zhang, Construction of luminescent three-dimensional Ln(III)–Zn(II) heterometallic coordination polymers based on 2-pyridyl imidazole dicarboxylate, CrystEngComm 14 (2012) 8236–8243; (c) S.L. Cai, S.R. Zheng, Z.Z. Wen, J. Fan, W.G. Zhang, A series of new threedimensional d–f heterometallic coordination polymers with rare 10-connected bct net topology based on planar hexanuclear heterometallic second building units, Cryst. Growth Des. 12 (2012) 5737–5745; (d) S.L. Cai, S.R. Zheng, M. Pan, J.B. Tan, J. Fan, W.G. Zhang, An unprecedented (3,4,14)-connected 3D metal–organic framework based on planar octanuclear lead(II) clusters as a secondary building unit, CrystEngComm 14 (2012) 1193–1196. [14] (a) H. Jia, Y. Li, Z. Xiong, C. Wang, G. Li, Five metal–organic frameworks from 3,4dimethylphenyl substituted imidazole dicarboxylate: syntheses, structures and properties, Dalton Trans. 43 (2014) 3704–3715;
[15]
[16]
[17]
[18]
(b) C. Wang, T. Wang, W. Zhang, H. Lu, G. Li, Two unprecedented transition-metal– organic frameworks showing one dimensional–hexagonal channel open network and two-dimensional sheet structures, Cryst. Growth Des. 12 (2012) 1091–1094. Z.L. Fang, S.R. Zheng, J. Fan, W.G. Zhang, In situ synthesis of a zwitterionic ligand and formation of a Eu(III) coordination polymer with double-bridged connectors, Inorg. Chem. Commun. 20 (2012) 122–125. S. Quici, M. Cavazzini, G. Marzanni, G. Accorsi, N. Armaroli, B. Ventura, F. Barigellett, Visible and near-infrared intense luminescence from water-soluble lanthanide [Tb(III), Eu(III), Sm(III), Dy(III), Pr(III), Ho(III), Yb(III), Nd(III), Er(III)] complexes, Inorg. Chem. 44 (2005) 529–537. F. Luo, Y. Che, J. Zheng, Employing La2-(La = Eu, Tb, Pr) or Co3-based molecule building blocks to construct 3,8-connected nets: hydrothermal synthesis, structure, luminescence, and magnetic properties, Cryst. Growth Des. 8 (2008) 2006–2010. M.S. Liu, Q.Y. Yu, Y.P. Cai, C.Y. Su, X.M. Lin, X.X. Zhou, J.W. Cai, One-, two-, and threedimensional lanthanide complexes constructed from pyridine-2,6-dicarboxylic acid and oxalic acid ligands, Cryst. Growth Des. 8 (2008) 4083–4091.