English

• 1. INTRODUCTION

  Recently, coordination polymers (CPs) composed of central metal ions and various multi-functional organic ligands have received increasing attention owing to their unique structural features and potential application^[1–3]. Consequently, many relevant reports show that the architectures and corresponding topologies of CPs are influenced by ineluctable factors, such as organic ligands, metal ions, solvents, temperature, pH values, and counter ions^[4–9]. Among many organic ligands, thiophenedicarboxylic acids containing multiple binding modes are useful building blocks in the assembly of CPs. At present, 2,5-thiophenedicarboxylic acid, 3,4-thiophenedicarboxylic acid, 3-nitro-thiophene-2,5-dicarboxylic acid, and methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate ligand have been used to construct diverse CPs^[10-16]. However, the 2,5-dicarboxylic acid-3,4-ethylene dioxythiophene ligand with more coordination sites has seldom been researched so far^{[17, 18]}.

  A new CP material, [Zn₂(L)₂(bpp)(H₂O)₂]_n, was systhesied by using 2,5-dicarboxylic acid-3,4-ethylene dioxythiophene and 1,3-bis(4-pyridyl)propane mixed ligands in high yield. Structure analysis reveals that the compound is a three-dimensional (3D) network with 2-fold interpenetrated pcu topology, and it is further characterized by elemental analysis, infrared spectra (IR), thermogravimetric (TG) analysis and powder X-ray diffraction (PXRD). Moreover, this compound displays luminescence emission in the solid state at room temperature.

  2. EXPERIMENTAL

  Chemicals of reagent grade were used as received. Elemental analyses for C, H, and N were carried out on a Flash 2000 elemental analyzer. IR spectra were recorded as KBr pellets on a Nicolet Avatar-360 spectrometer. PXRD patterns were obtained on a Bruker D8-ADVANCE X-ray diffractometer with CuKα radiation (λ = 1.5418 Å). The TGA was performed using a SDTQ600 thermogravimetric analyzer at a heating rate of 10 ℃·min⁻¹ under flowing air. Fluorescence measurements were recorded on a Hitachi F4500 fluorescence spectrophotometer.

  2.1 Synthesis of [Zn₂(L)₂(bpp)(H₂O)₂]_n (1)

  A mixture of H₂L (23.0 mg, 0.1 mmol), bpp (19.8 mg, 0.1 mmol), Zn(NO₃)₂·6H₂O (44.6 mg, 0.15 mmol), 5 mL N, N-dimethylformamide, and 3 mL deionized water was sealed in a 25 mL glass bottle and heated at 90 ℃ for 3 days, followed by cooling to room temperature. Yellow block crystals of 1 were collected (yield: 72% based on H₂L). Anal. Calcd. for C₂₉H₂₆N₂O₁₄S₂Zn₂ (%): C, 42.37; H, 3.17; N, 3.41. Found (%): C, 42.29; H, 3.26; N, 3.32. IR data (KBr, cm⁻¹): 3393(w), 2910(w), 2862(w), 1654(s), 1603(m), 1434 (m), 1374(s), 1339(s), 1253(m), 1087(s), 1025(m), 960(m), 846(m), 821(m), 790(s), 759(m), 737(m), 727(m), 657(m).

  2.2 X-ray structure determination

  X-ray data of 1 were collected on a Rigaku Oxford Diffraction SuperNova diffractometer using MoKα radiation. The structure was solved by direct methods based on the Olex2 program as an interface together with the SHELXT and SHELXL programs in order to solve and refine the structure, respectively^[19–21]. All non-hydrogen atoms were refined anisotropically and hydrogen atoms were placed at the calculation positions. A total of 13336 reflections (6.65 < 2θ < 49.99º) were collected including 2937 unique ones (R_int = 0.0610), of which 2371 with I > 2σ(I) were observed and used for structural elucidation. The final R = 0.0466 and wR = 0.0933, S = 1.066, (∆ρ)_max = 0.87 and (∆ρ)_min = −0.38 e/ų. Selected bond lengths and bond angles are listed in Table 1, and the hydrogen bond lengths and bond angles are displayed in Table 2.

  Table 1

  

  Table 1.  Selected Bond Lengths (Å) and Bond Angles (°) for 1

  DownLoad: CSV

  Bond	Dist.		Bond	Dist.		Bond	Dist.
  Zn(1)−O(1)	1.975(3)		Zn(1)−N(1)	2.115(5)		Zn(1)−O(7)	2.150(4)
  Zn(1)−O(8)	2.070(4)		Zn(2)−O(3)	2.062(3)		Zn(2)−O(2)#5	2.077(3)
  Zn(2)−O(7)#6	2.235(4)		Zn(2)−N (2)#4	2.095(4)
  Angle	(°)		Angle	(°)		Angle	(°)
  N(1)−Zn(1)−O(7)	175.19(16)		N(1)−Zn(1)−O(1)	89.69(10)		O(1)#1−Zn(1)−O(1)	119.80(17)
  O(1)−Zn(1)−O(7)	92.72(10)		O(1)−Zn(1)−O(8)	120.02(8)		N(1)−Zn(1)−O(8)	86.74(17)
  O(7)−Zn(1)−O(8)	88.45(15)		O(7)#5−Zn(2)−N(2)#4	175.38(15)		O(2)#5−Zn(2)−N(2)#4	88.36(11)
  O(2)#6−Zn(2)−O(2)#5	98.25(17)		O(2)#5−Zn(2)−O(7)#5	88.62(10)		O(3)−Zn(2)−N(2)#4	91.66(12)
  O(3)−Zn(2)−O(2)#5	87.69(12)		O(3)−Zn(2)−O(2)#6	174.06(12)		O(3)#7−Zn(2)−O(2)#5	174.07(12)
  O(3)−Zn(2)−O(3)#7	86.38(17)		O(3)−Zn(2)−O(7)#5	91.70(11)
  Symmetry transformation: #1: x, 1.5 − y, z; #4: 1.5 − x, 1.5 − y, z − 0.5; #5: 0.5 − x, 1 − y, z − 0.5; #6: 0.5 − x, y −0.5, z −0.5; #7: x, 0.5 − y, z

  Table 2

  

  Table 2.  Hydrogen Bond Lengths (Å) and Bond Angles (°) in 1

  DownLoad: CSV

  D–H⋅⋅⋅A	d(D–H)	d(H⋅⋅⋅A)	d(D⋅⋅⋅A)	∠DHA
  O(7)−H(7)···O(4)#8	0.851	1.855	2.666(1)	158.61
  O(8)−H(8C)···O(3)#9	0.850	2.185	3.004(2)	161.41
  O(8)−H(8D)···O(3)#10	0.850	2.432	3.004(2)	125.21
  O(8)−H(8D)···O(5)#10	0.850	2.200	2.702(2)	160.87
  Symmetry codes: #8: 0.5 − x, 0.5 + y, 0.5 + z; #9: 1 − x, 0.5 + y, 1 − z; #10: 1 − x, 1 − y, 1 − z

  3. RESULTS AND DISCUSSION

  3.1 Crystal structure of [Zn₂(L)₂(bpp)(H₂O)₂]_n (1)

  X-ray crystallography study reveals that compound 1 crystallizes in the orthorhombic Pnma space group. There are two half crystallographically independent Zn²⁺ ions, one L^2– anion, one half bpp ligand and two ligated water molecules in the asymmetric unit. The Zn(1) atom with a distorted square-pyramidal coordination geometry is five-coordinated by one pyridyl nitrogen atom, two carboxylate oxygen atoms from two L^2– anions and two oxygen atoms from two ligated water molecules. The Zn(2) atom occupies the center of a distorted octahedron and is coordinated by four oxygen atoms of L^2– anions, one pyridyl nitrogen atom and one oxygen atom of one water ligated molecule (Fig. 1). The Zn−O distances fall in the range of 1.975(3)~2.235(4) Å and Zn−N bond lengths are 2.095(4) and 2.114(5) Å, respectively, which are within the normal ranges^{[22, 23]}.

  Figure 1

  

  Figure 1.  (a) Coordination environment of the Zn(Ⅱ) center. Displacement ellipsoids are drawn at the 30% probability level. Hydrogen atoms are omitted for clarity. Symmetry codes: #1: x, 1.5 − y, z; #3: 0.5 − x, y − 0.5, z − 0.5; #4: 1.5 − x, 1.5 − y, z − 0.5; #5: 0.5 − x, 1 − y, z − 0.5; #6: 0.5 − x, y − 0.5, z − 0.5; #7: x, 0.5 − y, z

  DownLoad: Full-Size Img PowerPoint

  In this structure, the completely deprotonated L^2– anion takes on a μ₃-(η¹, η¹)-(η¹, η⁰) coordination mode to connect Zn²⁺ ions and the bpp ligand is bound to two Zn²⁺ ions via the pyridyl nitrogen donors thereof. In virtue of ligated water entities and the bridging roles of carboxylates, two adjacent Zn atoms are combined to generate a [Zn₂(μ-H₂O)(COO^–)₂] dinuclear unit with the Zn···Zn separation of 3.5556(2) Å (Fig. 2a). As a consequence, such dinuclear units are extended by the L^2– anion and bpp ligand to afford a 3D coordination structure (Fig. 2b). In each bpp ligand, the dihedral angle between two pyridine planes is 66.3^o. Note that the O(7) water molecule is hydrogen bonded to an uncoordinated carboxylate oxygen atom around the [Zn₂(μ-H₂O)(COO^–)₂] unit (O(7)···O(4), distance = 2.666 Å; O(7)–H(7)···O(4) angle = 158.61^o), which may further stabilize this dinuclear unit. Hydrogen bonds between the O(8) water molecule and carboxylate oxygen atoms further consolidate the resulting 3D structure (Table 2). In topology, each dinuclear [Zn₂(μ-H₂O)(COO^–)₂] unit is bonded to six adjacent ones via two bpp ligands and four L^2– anions, so it could be regarded as a 6-connected node, and bpp and L^2– anions could be viewed as linear linkers. Therefore, compound 1 could be simplified into a 6-connected pcu topological network with the Schläfli symbol of {4¹².6³} (Fig. 2c), similar to the reported structures^{[24, 25]}. Moreover, the large channels in the single framework of 1 are occupied by another identical pcu net, leading to the final 2-fold interpenetrated structure (Fig. 2d).

  Figure 2

  

  Figure 2.  (a) [Zn₂(μ-H₂O)(COO^–)₂] dinuclear unit. (b) 3D architecture of compound 1. (c) Schematic representation of the 3D 6-connected pcu topological network. (d) Schematic representation of the 2-fold interpenetrated structure

  DownLoad: Full-Size Img PowerPoint

  3.2 IR spectrum, PXRD pattern and thermal analysis

  IR spectra of compound 1 show broad absorption at 3393 cm⁻¹, which indicates the presence of ligated water molecules. The strong absorption peaks of asymmetric stretching vibrations have been observed at 1654 and 1603 cm⁻¹, respectively. The strong absorption peaks at 1374 and 1339 cm⁻¹ could be ascribed to symmetric stretching vibrations. And no absorption peaks around 1700 cm⁻¹ are discovered, illustrating complete deprotonation of carboxyl groups in compound 1.

  The phase purity of compound 1 was recorded by PXRD pattern of the bulk sample, which could be indexed to the simulated pattern based on the single-crystal X-ray diffraction data, indicating that the corresponding sample is homogeneously pure phase (Fig. 3). The TGA experiment was conducted to evaluate the thermal stability of compound 1 under dry air atmosphere from 30 to 700 ℃. As seen in Fig. 4, compound 1 is thermally stable up to 131 ℃ and the first weight loss of 4.45% in 131~161 ℃ indicates the exclusion of two coordinated water molecules (calcd.: 4.38%). With that, the remaining solid is thermally stable to 270 ℃. On further heating, a rapid weight loss is observed, deriving from the decomposition of the host network. Above 564 ℃, the whole framework collapses completely, forming ZnO as a final product (calcd.: 19.48%, found: 19.42%).

  Figure 3

  

  Figure 3.  TGA curve for 1

  DownLoad: Full-Size Img PowerPoint

  Figure 4

  

  Figure 4.  PXRD pattern of 1 simulated from X-ray single-crystal diffraction data and experimental data

  DownLoad: Full-Size Img PowerPoint

  3.3 Photoluminescent property

  As is well known, many luminescent Zn(Ⅱ) CPs usually present potential applications with chemical sensors and photoelectric fields, so the solid state luminescence of compound 1 is determined at room temperature. As shown in Fig. 5, compound 1 exhibits the luminescent emission band at 368 nm (λ_ex = 278 nm). In order to explore the origin of emission band, the photoluminescence properties of free organic ligands were also studied. Free H₂L shows a weak emission band centered at 431 nm (λ_ex = 276 nm) and free bpp shows two weak emission bands at 382 and 443 nm (λ_ex = 328 nm), respectively. Compared with organic ligands, the emission of compound 1 is blue-shifted, which may be ascribed to the intraligand π-π^* charge transfer^[26–28]. The enhancement of the intensity of 1 may be ascribed to the increased rigidity of the ligand upon metal coordination, which, to some extent, effectively reduces the energy loss.

  Figure 5

  

  Figure 5.  Solid-state emission spectra of 1

  DownLoad: Full-Size Img PowerPoint

  4. CONCLUSION

  In summary, a three-dimensional coordination polymer based upon the 2,5-dicarboxylic acid-3,4-ethylene dioxythiophene and 1,3-di(4-pyridyl)propane mixed ligands was designed and synthesized under solvothermal condition. Structure analysis exhibits the compound features a 3D network with a 2-fold interpenetrated pcu topology. The compound has been characterized by many methods. Moreover, the compound shows photoluminescence and could be a potential candidate for luminescence material.

  
  
• 1. [1]

     Li, D. S.; Wu, Y. P.; Zhao, J.; Zhang, J.; Lu, J. Y. Metal-organic frameworks based upon non-zeotype 4-connected topology. Coord. Chem. Rev. 2014, 26, 1–27.

  2. [2]

     Dhakshinamoorthy, A.; Garcia, H. Metal-organic frameworks as solid catalysts for the synthesis of nitrogen-containing heterocycles. Chem. Soc. Rev. 2014, 43, 5750–5765. doi: 10.1039/C3CS60442J

  3. [3]

     Wang, H.; Meng, W.; Wu, J.; Ding, J.; Hou, H.; Fan, Y. Crystalline central-metal transformation in metal-organic frameworks. Coord. Chem. Rev. 2016, 307, 130–146. doi: 10.1016/j.ccr.2015.05.009

  4. [4]

     Chen, S. S.; Li, J. L.; Li, W. D.; Guo, X. Z; Zhao, Y. Four new transition metal coordination polymers based on mixed 4-imidazole and carboxylate-sulfonate ligands: syntheses, structures, and properties. J. Solid State Chem. 2019, 277, 510–518. doi: 10.1016/j.jssc.2019.07.008

  5. [5]

     Liang, J.; Zhao, Q.; Gao, L.; Zhang, J.; Niu, X.; Hu, T. Structural diversity and fluorescent sensing of four novel compounds based on rigid terphenyl-3, 3΄΄, 5, 5΄΄-tetracarboxylic acid. J. Solid State Chem. 2019, 274, 280–285. doi: 10.1016/j.jssc.2019.03.047

  6. [6]

     Xin, L. Y.; Liu, G. Z.; Li, X. L.; Wang, L. Y. Structural diversity for a series of metal(Ⅱ) compounds based on flexible 1,2-phenylenediacetate and dipyridyl-type coligand. Cryst. Growth Des. 2012, 12, 147−157. doi: 10.1021/cg200903k

  7. [7]

     Hua, J. A.; Zhao, Y.; Kang, Y. S.; Lu, Y.; Sun, W. Y. Solvent-dependent zinc(Ⅱ) coordination polymers with mixed ligands: selective sorption and fluorescence sensing. Dalton Trans. 2015, 44, 11524−11532. doi: 10.1039/C5DT01386K

  8. [8]

     Wan, J.; Cai, S. L.; Zhang, K.; Li, C. J.; Feng, Y.; Fan, J.; Zheng, S. R.; Zhang, W. G. Anion- and temperature-dependent assembly, crystal structures and luminescence properties of six new Cd(Ⅱ) coordination polymers based on 2,3,5,6-tetrakis(2-pyridyl)pyrazine. CrystEngComm. 2016, 18, 5164−5176. doi: 10.1039/C6CE00853D

  9. [9]

     Seetharaj, R.; Vandana, P. V.; Arya, P.; Mathew, S. Dependence of solvents, pH, molar ratio and temperature in tuning metal organic framework architecture. Arab. J. Chem. 2019, 12, 295−315. doi: 10.1016/j.arabjc.2016.01.003

  10. [10]

      He, Y. P.; Tan, Y. X.; Zhang, J. Organic cation templated synthesis of three zinc-2,5-thiophenedicarboxylate frameworks for selective gas sorption. Cryst. Growth Des. 2014, 14, 3493−3498. doi: 10.1021/cg500436g

  11. [11]

      Xue, H.; Chen, Q.; Jiang, F.; Yuan, D.; Lv, G.; Liang, L.; Liu, L.; Hong, M. A regenerative metal-organic framework for reversible uptake of Cd(Ⅱ): from effective adsorption to in situ detection. Chem. Sci. 2016, 7, 5983–5988. doi: 10.1039/C6SC00972G

  12. [12]

      Xue, L. P. Construction of a new two-fold interpenetrated three-dimensional cobalt(Ⅱ) coordination polymer based on 2,5-thiophenedicarboxylic acid and bis(imidazol-1-yl)methane. Chin. J. Struct. Chem. 2018, 37, 1133–1138.

  13. [13]

      Xue, L. P.; Chang, X. H.; Li, S. H.; Ma, L. F.; Wang, L. Y. The structural diversity and photoluminescent properties of cadmium thiophenedicarboxylate coordination polymers. Dalton Trans. 2014, 43, 7219–7226. doi: 10.1039/C4DT00211C

  14. [14]

      Xue, L. P.; Li, Z. H.; Ma, L. F.; Wang, L. Y. Crystal engineering of cadmium coordination polymers decorated with nitro-functionalized thiophene-2,5-dicarboxylate and structurally related bis(imidazole) ligands with varying flexibility. CrystEngComm. 2015, 17, 6441–6449. doi: 10.1039/C5CE01248A

  15. [15]

      Xue, L. P.; He, S. J.; Wang, X. N; Zhang, D. D. Construction of two photoluminescent sulfur-containing cadmium(Ⅱ) coordination polymers with 4-connected topology based on a methyl-3-hydroxy-5-carboxy-2-thiophenecarboxylate ligand. J. Sulfur Chem. 2018, 39, 173–181. doi: 10.1080/17415993.2017.1408810

  16. [16]

      Xue, L. P. A dinuclear Cd(Ⅱ) cluster-based coordination polymer: synthesis, structure and luminescence property. Chin. J. Struct. Chem. 2018, 37. 119–124.

  17. [17]

      Wu, X. Q.; Ma, J. G.; Han L.; Chen, D. M.; Gu, W.; Yang, G. M.; Cheng, P. Metal-organic framework biosensor with high stability and selectivity in a bio-mimic environment. Chem. Commun. 2015, 51, 9161–9164. doi: 10.1039/C5CC02113H

  18. [18]

      Guo, C. L.; Zhuo, X.; Li, Y. Z.; Zheng, H. G. Synthesis, crystal structures, and fluorescence properties of six compounds with thiophene derivative carboxylic acid ligand. Inorg. Chim. Acta 2009, 362, 491–501. doi: 10.1016/j.ica.2008.04.044

  19. [19]

      Dolomanov, O. V.; Bourhis, L. J.; Gildea, R. J.; Howard, J. A. K.; Puschmann, H. OLEX2: a complete structure solution, refinement and analysis program. J. Appl. Cryst. 2009, 42, 339–341. doi: 10.1107/S0021889808042726

  20. [20]

      Sheldrick, G. M. SHELXT-integrated space-group and crystal-structure determination. Acta Cryst. 2015, A71, 3–8.

  21. [21]

      Sheldrick, G. M. Crystal structure refinement with SHELXL. Acta Cryst. 2015, C71, 3–8.

  22. [22]

      Li, G. L.; Yin, W. D.; Liu, G. Z.; Ma, L. F.; Huang, L. L.; Li, L.; Wang, L. Y. Single-crystal to single-crystal photochemical structure transformation of a ladder-like coordination polymer with dinuclear Zn(Ⅱ) platform. Inorg. Chem. Commun. 2014, 43, 165–168. doi: 10.1016/j.inoche.2014.02.037

  23. [23]

      Xue, L. P.; Chang, X. H.; Ma, L. F.; Wang, L. Y. Four d¹⁰ metal coordination polymers based on bis(2-methyl imidazole) spacers: syntheses, interpenetrating structures and photoluminescence properties. RSC Adv. 2014, 4, 60883–60890. doi: 10.1039/C4RA10331A

  24. [24]

      Li, Z. H.; Xue, L. P.; Miao, S. B.; Zhao, B. T. Assembly of 4-, 6- and 8-connected Cd(Ⅱ) pseudo-polymorphic coordination polymers: synthesis, solvent-dependent structural variation and properties. J. Solid State Chem. 2016, 240, 9–15. doi: 10.1016/j.jssc.2016.05.005

  25. [25]

      Ma, L. F.; Han, M. L.; Qin, J. H.; Wang, L. Y.; Du, M. Mn^Ⅱ Coordination polymers based on bi-, tri-, and tetranuclear and polymeric chain building units: crystal structures and magnetic properties. Inorg. Chem. 2012, 51, 9431–9442. doi: 10.1021/ic3012537

  26. [26]

      Lan, H. H.; Li, X. T.; Chu, W. J.; Xu, C. Y.; Ji, B. M. Syntheses, crystal structures and luminescence properties of two Zn(Ⅱ) coordination polymers based on flexible bisbenzimidazole ligand. Chin. J. Inorg. Chem. 2019, 35, 1586–1902.

  27. [27]

      Kokunov, Y. V.; Gorbunova, Y. E.; Kovalev, V. V.; Kozyukhin, A. S. 2D-layered structure of coordination polymer, zinc trifluoroacetate-1,3-bis (4-pyridyl) propane. Russ. J. Inorg. Chem. 2014, 59, 187–191. doi: 10.1134/S0036023614030127

  28. [28]

      Han, Z. B.; Liang, Y. F.; Zhou, M.; Zhang, Y. R.; Li, L.; Tong, J. Two chiral Zn(Ⅱ) metal-organic frameworks with dinuclear Zn₂(COO)₃ secondary building units: a 2-D (6, 3) net and a 3-D 3-fold interpenetrating (3, 5)-connected network. CrystEngComm. 2012, 14, 6952–6956. doi: 10.1039/c2ce25430a

• 

  Figure 1  (a) Coordination environment of the Zn(Ⅱ) center. Displacement ellipsoids are drawn at the 30% probability level. Hydrogen atoms are omitted for clarity. Symmetry codes: #1: x, 1.5 − y, z; #3: 0.5 − x, y − 0.5, z − 0.5; #4: 1.5 − x, 1.5 − y, z − 0.5; #5: 0.5 − x, 1 − y, z − 0.5; #6: 0.5 − x, y − 0.5, z − 0.5; #7: x, 0.5 − y, z

  下载: 全尺寸图片 幻灯片
  

  Figure 2  (a) [Zn₂(μ-H₂O)(COO^–)₂] dinuclear unit. (b) 3D architecture of compound 1. (c) Schematic representation of the 3D 6-connected pcu topological network. (d) Schematic representation of the 2-fold interpenetrated structure

  下载: 全尺寸图片 幻灯片
  

  Figure 3  TGA curve for 1

  下载: 全尺寸图片 幻灯片
  

  Figure 4  PXRD pattern of 1 simulated from X-ray single-crystal diffraction data and experimental data

  下载: 全尺寸图片 幻灯片
  

  Figure 5  Solid-state emission spectra of 1

  下载: 全尺寸图片 幻灯片

  Table 1.  Selected Bond Lengths (Å) and Bond Angles (°) for 1

  Bond	Dist.		Bond	Dist.		Bond	Dist.
  Zn(1)−O(1)	1.975(3)		Zn(1)−N(1)	2.115(5)		Zn(1)−O(7)	2.150(4)
  Zn(1)−O(8)	2.070(4)		Zn(2)−O(3)	2.062(3)		Zn(2)−O(2)#5	2.077(3)
  Zn(2)−O(7)#6	2.235(4)		Zn(2)−N (2)#4	2.095(4)
  Angle	(°)		Angle	(°)		Angle	(°)
  N(1)−Zn(1)−O(7)	175.19(16)		N(1)−Zn(1)−O(1)	89.69(10)		O(1)#1−Zn(1)−O(1)	119.80(17)
  O(1)−Zn(1)−O(7)	92.72(10)		O(1)−Zn(1)−O(8)	120.02(8)		N(1)−Zn(1)−O(8)	86.74(17)
  O(7)−Zn(1)−O(8)	88.45(15)		O(7)#5−Zn(2)−N(2)#4	175.38(15)		O(2)#5−Zn(2)−N(2)#4	88.36(11)
  O(2)#6−Zn(2)−O(2)#5	98.25(17)		O(2)#5−Zn(2)−O(7)#5	88.62(10)		O(3)−Zn(2)−N(2)#4	91.66(12)
  O(3)−Zn(2)−O(2)#5	87.69(12)		O(3)−Zn(2)−O(2)#6	174.06(12)		O(3)#7−Zn(2)−O(2)#5	174.07(12)
  O(3)−Zn(2)−O(3)#7	86.38(17)		O(3)−Zn(2)−O(7)#5	91.70(11)
  Symmetry transformation: #1: x, 1.5 − y, z; #4: 1.5 − x, 1.5 − y, z − 0.5; #5: 0.5 − x, 1 − y, z − 0.5; #6: 0.5 − x, y −0.5, z −0.5; #7: x, 0.5 − y, z

  下载: 导出CSV

  Table 2.  Hydrogen Bond Lengths (Å) and Bond Angles (°) in 1

  D–H⋅⋅⋅A	d(D–H)	d(H⋅⋅⋅A)	d(D⋅⋅⋅A)	∠DHA
  O(7)−H(7)···O(4)#8	0.851	1.855	2.666(1)	158.61
  O(8)−H(8C)···O(3)#9	0.850	2.185	3.004(2)	161.41
  O(8)−H(8D)···O(3)#10	0.850	2.432	3.004(2)	125.21
  O(8)−H(8D)···O(5)#10	0.850	2.200	2.702(2)	160.87
  Symmetry codes: #8: 0.5 − x, 0.5 + y, 0.5 + z; #9: 1 − x, 0.5 + y, 1 − z; #10: 1 − x, 1 − y, 1 − z

  下载: 导出CSV
•