English

• 0.   Introduction

  In recent years, great interest has been focused on the design and hydrothermal syntheses of functional coordination polymers owing to their intriguing architectures and topologies, as well as potential applications in catalysis, magnetism, luminescence and gas absorption^[1-10]. Up to now, a large numbers of coordination polymers have been obtained by hydrothermal methods, which are optimal for crystal growth^{[1, 3-4, 11-13]}. The mechanism of the complicated reactions under hydrothermal methods remain unclear, which depends directly on the interplay of starting materials, pH value, template, and reaction temperature^[14-18].

  In this regard, the selection of organic ligands is one of the most important aspects. Among a wide variety of organic ligands, various types of aromatic polycarboxylic acids have been proved to be versatile and efficient candidates for constructing diverse coordination polymers due to their rich coordination chemistry, tunable degree of deprotonation, and ability to act as H-bond acceptors and donors^{[15-16, 18-22]}.

  On the basis of the above account, we selected 5-bromoisophthalic acid (H₂BIPA) and investigated the influence of the reaction conditions on the structures of coordination polymers under hydrothermal conditions.

  Herein, we report the syntheses, crystal structures, and magnetic properties of two Cu(Ⅱ) coordination compounds constructed from 5-bromoisophthalic acid ligand.

  1.   Experimental

  1.1   Reagents and physical measurements

  All chemicals and solvents were of AR grade and used without further purification. Carbon, hydrogen and nitrogen were determined using an Elementar Vario EL elemental analyzer. IR spectra were recorded using KBr pellets and a Bruker EQUINOX 55 spectrometer. Thermogravimetric analysis (TGA) data were collected on a LINSEIS STA PT1600 thermal analyzer with a heating rate of 10 ℃·min^-1. Magnetic susceptibility data were collected in a temperature range of 2~300 K with a Quantum Design SQUID Magnetometer MPMS XL-7 with a field of 0.1 T. A correction was made for the diamagnetic contribution prior to data analysis.

  1.2   Synthesis of [Cu(BIPA)(2, 2′-bipy)(H₂O)₂]· H₂O (1)

  A mixture of CuCl₂·2H₂O (0.017 g, 0.10 mmol), H₂BIPA (0.024 g, 0.10 mmol), 2, 2′-bipyridine (2, 2′-bipy, 0.016 g, 0.1 mmol), NaOH (0.008 g, 0.20 mmol) and H₂O (8 mL) was stirred at room temperature for 15 min, and then sealed in a 25 mL Teflon-lined stainless steel vessel, and heated at 120 ℃ for 3 days, followed by cooling to room temperature at a rate of 10 ℃·h^-1. Blue block-shaped crystals of 1 were isolated manually, and washed with distilled water. Yield: 58% (based on H₂BIPA). Anal. Calcd. for C₁₈H₁₇BrCuN₂O₇(%): C 41.83, H 3.32, N 5.42; Found(%): C 42.05, H 3.34, N 4.39. IR (KBr, cm^-1): 3 444w, 3 238m, 1 593s, 1 543s, 1 476w, 1 420m, 1 354s, 1 248w, 1 174w, 1 091w, 1 063w, 1 030w, 901w, 763m, 724m, 661w, 594w, 546w.

  1.3   Synthesis of [Cu₃(μ₃-BIPA)₂(μ-OH)₂(2, 2′-bipy)₂]_n (2)

  Synthesis of 2 was similar to 1 except using a different amount of NaOH (0.012 g, 0.30 mmol). Blue block-shaped crystals of 2 were isolated manually, and washed with distilled water. Yield: 38 % (based on H₂BIPA). Anal. Calcd. for C₃₆H₂₄Br₂Cu₃N₄O₁₀(%): C 42.26, H 2.36, N 5.48; Found(%): C 42.03, H 2.35, N 5.51. IR (KBr, cm^-1): 3 423w, 3 055w, 1 627m, 1 604s, 1 576m, 1 555m, 1 494w, 1 427w, 1 370m, 1 326s, 1 248 w, 1 158w, 1 119w, 1 086w, 1 024w, 886w, 767m, 728m, 657w, 634w, 546w. The compounds are insoluble in water and common organic solvents, such as methanol, ethanol, acetone and DMF.

  1.4   Structure determinations

  Two single crystals with dimensions of 0.26 mm×0.23 mm×0.22 mm (1) and 0.25 mm×0.18 mm×0.16 mm (2) were collected at 293(2) K on a Bruker SMART APEX Ⅱ CCD diffractometer with Mo Kα radiation (λ=0.071 073 nm). The structures were solved by direct methods and refined by full matrix least-square on F² using the SHELXTL-2014 program^[23]. All non-hydrogen atoms were refined anisotropically. All the hydrogen atoms were positioned geometrically and refined using a riding model. A summary of the crystallography data and structure refinements for 1 and 2 is given in Table 1. The selected bond lengths and angles for compounds 1 and 2 are listed in Table 2. Hydrogen bond parameters of compounds 1 and 2 are given in Table 3.

  Table 1

  

  Table 1.  Crystal data for compounds 1 and 2

  下载: 导出CSV

  Compound	1	2
  Chemical formula	C18H17BrCuN2O7	C36H24Br2Cu3N4O10
  Molecular weight	516.78	1 023.03
  Crystal system	Monoclinic	Monoclinic
  Space group	P21/c	P21/n
  a / nm	2.062 7(2)	0.985 21(4)
  b / nm	0.783 37(5)	1.741 02(7)
  c / nm	2.374 67(17)	1.030 43(7)
  β / (°)	91.907(7)	99.378(5)
  V / nm3	3.835 0(5)	1.743 84(16)
  Z	8	2
  F(000)	2 072	1 010
  θ range for data collection / (°)	3.286~25.050	3.538~25.044
  Limiting indices	-24 ≤ h ≤ 24, -9 ≤ k ≤ 8, -28 ≤ l ≤ 22	-9 ≤ h ≤ 11, -18 ≤ k ≤ 20, -11 ≤ l ≤ 12
  Reflection collected, unique (Rint)	13 849, 6 782 (0.082 2)	5 731, 3 084 (0.033 4)
  Dc / (g·cm-3)	1.790	1.948
  μ / mm-1	3.268	4.172
  Data, restraint, parameter	6 782, 0, 523	3 084, 0, 254
  Goodness-of-fit on F2	1.000	1.048
  Final R indices [I≥2σ(I)] R1, wR2	0.060 8, 0.084 7	0.041 7, 0.093 7
  R indices (all data) R1, wR2	0.116 4, 0.146 7	0.061 8, 0.107 2
  Largest diff. peak and hole / (e·nm-3)	915 and -534	1 234 and -708

  Table 2

  

  Table 2.  Selected bond lengths (nm) and bond angles (°) for compounds 1 and 2

  下载: 导出CSV

  1
  Cu(1)-O(2)	0.197 1(5)	Cu(1)-O(9)	0.197 1(5)	Cu(1)-O(10)	0.223 6(5)
  Cu(1)-N(1)	0.200 2(7)	Cu(1)-N(2)	0.200 3(6)	Cu(2)-O(5)	0.197 2(5)
  Cu(2)-O(11)	0.224 2(4)	Cu(2)-O(12)	0.195 7(5)	Cu(2)-N(3)	0.202 6(6)
  Cu(2)-N(4)	0.200 7(6)
  O(9)-Cu(1)-O(2)	93.6(2)	O(9)-Cu(1)-N(1)	93.3(2)	O(2)-Cu(1)-N(1)	168.4(3)
  O(9)-Cu(1)-N(2)	164.4(2)	O(2)-Cu(1)-N(2)	90.6(3)	N(2)-Cu(1)-N(1)	80.3(3)
  O(9)-Cu(1)-O(10)	90.96(19)	O(2)-Cu(1)-O(10)	96.7(2)	N(1)-Cu(1)-O(10)	92.5(2)
  N(2)-Cu(1)-O(10)	103.5(2)	O(5)-Cu(2)-O(12)	94.0(2)	O(12)-Cu(2)-N(4)	165.1(2)
  O(5)-Cu(2)-N(4)	90.0(2)	O(12)-Cu(2)-N(3)	93.8(2)	O(5)-Cu(2)-N(3)	168.0(2)
  N(4)-Cu(2)-N(3)	80.3(3)	O(12)-Cu(2)-O(11)	91.90(19)	O(11)-Cu(2)-O(5)	98.40(19)
  N(4)-Cu(2)-O(11)	101.8(2)	N(3)-Cu(2)-O(11)	90.4(2)
  2
  Cu(1)-O(1)	0.193 0(3)	Cu(1)-O(3)A	0.264 9(4)	Cu(1)-O(5)	0.190 2(4)
  Cu(1)-N(1)	0.200 1(4)	Cu(1)-N(2)	0.202 2(4)	Cu(2)-O(4)A	0.195 2(3)
  Cu(2)-O(4)B	0.195 2(3)	Cu(2)-O(5)	0.192 2(4)	Cu(2)-O(5)C	0.192 2(4)
  O(5)-Cu(1)-O(1)	97.96(15)	O(5)-Cu(1)-N(1)	92.83(16)	O(1)-Cu(1)-N(1)	164.80(16)
  O(5)-Cu(1)-N(2)	169.39(16)	O(1)-Cu(1)-N(2)	90.64(14)	N(1)-Cu(1)-N(2)	79.96(15)
  O(1)-Cu(1)-O(3)A	100.94(15)	O(5)-Cu(1)-O(3)A	79.77(14)	N(1)-Cu(1)-O(3A)	91.46(15)
  N(2)-Cu(1)-O(3A)	92.57(15)	O(5)-Cu(2)-O(4)A	91.76(14)	O(5)-Cu(2)-O(4)B	88.24(14)
  Symmetry codes: A: x+1, y, z; B: -x+1, -y, -z+1; C: -x+2, -y, -z+1 for 2.

  Table 3

  

  Table 3.  Hydrogen bond parameters of compounds 1 and 2

  下载: 导出CSV

  Compound	D-H…A	d(D-H) / nm	d(H…A) / nm	d(D…A) / nm	∠DHA / (°)
  1	O(9)-H(1W)…O(1)	0.087 6	0.178 1	0.256 0	147.0
  	O(9)-H(2W)…O(7)A	0.087 7	0.181 1	0.266 9	165.3
  	O(10)-H(3W)…O(8)A	0.086 8	0.193 7	0.279 8	171.2
  	O(10)-H(4W)…O(7)B	0.085 0	0.183 1	0.268 1	179.1
  	O(11)-H(5W)…O(4)C	0.086 1	0.197 0	0.269 3	140.9
  	O(11)-H(6W)…O(3)D	0.085 0	0.195 9	0.280 9	179.5
  	O(12)-H(7W)…O(4)D	0.085 0	0.185 7	0.270 7	179.1
  	O(12)-H(8W)…O(6)	0.087 4	0.178 5	0.255 6	145.8
  	O(13)-H(9W)…O(8)A	0.085 0	0.204 4	0.289 4	179.1
  	O(14)-H(11W)…O(3)E	0.085 0	0.196 8	0.281 6	175.3
  2	O(5)-H(1)…O(2)	0.076 0	0.215 1	0.281 6	146.5
  Symmetry codes: A: -x, y+1/2, -z+1/2; B: x, y+1, z; C: x, y-1, z; D: -x+1, y-1/2, -z+1/2; E: -x+1, y+1/2, -z+1/2 for 1.

  CCDC: 1922559, 1; 1922560, 2.

  2.   Results and discussion

  2.1   Description of the structure

  2.1.1   [Cu(BIPA)(2, 2′-bipy)(H₂O)₂]·H₂O (1)

  Single-crystal X-ray diffraction analysis reveals that compound 1 crystallizes in the monoclinic space group P2₁/c. Its asymmetric unit contains two mononuclear copper(Ⅱ) units and two lattice water molecules (Fig. 1). In each [Cu(BIPA)(2, 2′-bipy)(H₂O)₂] unit, the Cu(Ⅱ) ions are five-coordinated and form a distorted square-pyramidal {CuN₂O₃} geometry with the τ parameters of 0.066 7 or 0.048 3 (τ=0 or 1 for a regular square-pyramidal or trigonal-bipyramidal geometry, respectively)^[24]. It is taken by a carboxylate O atom of BIPA^2-, two H₂O ligands, and two N donors from the 2, 2′-bipy ligand. The Cu-O bonds (0.195 7(5)~0.224 2(4) nm) and the Cu-N distances (0.200 2(7)~0.202 6(6) nm) agree with literature data^{[3, 22, 25]}. In 1, the BIPA^2- moiety acts as a terminal ligand (mode Ⅰ, Scheme 1). Discrete mononuclear copper(Ⅱ) units are assembled, via the O-H…O hydrogen bonds, into a 2D H-bonded sheet (Fig. 2 and Table 3).

  Figure 1

  

  Figure 1.  Drawing of asymmetric unit of compound 1 with 30% probability thermal ellipsoids

  H atoms and lattice water molecules were omitted for clarity

  下载: 全尺寸图片 幻灯片

  Scheme 1

  

  Scheme 1.  Coordination modes of BIPA2- ligands in compounds 1 and 2

  下载: 全尺寸图片 幻灯片

  Figure 2

  

  Figure 2.  Perspective of 2D sheet in 1

  Dashed lines present the H-bonds

  下载: 全尺寸图片 幻灯片

  2.1.2   [Cu₃(μ₃-BIPA)₂(μ-OH)₂(2, 2′-bipy)₂]_n (2)

  The asymmetric unit of 2 consists of two Cu(Ⅱ) ions (Cu1 with full occupancy and Cu2 with half occupancy), one μ₃-BIPA^2- block, one 2, 2′-bipy ligand, and μ-OH^- linker. As shown in Fig. 3, five-coordinated Cu1 atom reveals a distorted square-pyramidal {CuN₂O₃} geometry with the τ parameters of 0.076 5, filled by two carboxylate O atoms from two individual μ₃-BIPA^2- blocks, one O atom from the μ-OH^- linker, and a pair of N atoms from 2, 2′-bipy ligand. The four-coordinated Cu2 atom shows a distorted {CuN₂O₂} square-planar geometry, which is taken by two carboxylate O atoms from two different BIPA^2- blocks and two O atoms from two individual μ-OH^- linkers. The Cu-O lengths range from 0.190 2(4) to 0.264 9(4) nm, whereas the Cu-N lengths vary from 0.200 1(4) to 0.202 2(4) nm; these bonding parameters are comparable to those observed in other Cu(Ⅱ) compounds^{[3, 22, 25]}. In 2, the BIPA^2- block acts as a μ₃-linker, and its COO^- groups are monodentate or bidentate (mode Ⅱ, Scheme 1). The three adjacent Cu(Ⅱ) ions are bridged by means of two carboxylate groups from two different BIPA^2- blocks and two μ-OH^- linkers, giving rise to a trinuclear copper(Ⅱ) subunit (Fig. 4). In this Cu₃ subunit, the Cu1…Cu2 distance is 0.344 1(4) nm. The neig-hboring Cu₃ subunits are multiply interlinked by BIPA^2- blocks into a 1D chain (Fig. 4), having the shortest distance of 0.985 2 nm between the adjacent trinuclear copper(Ⅱ) subunits. The intrachain (N1/C9-C13 and C2A-C7A, Cg…Cg 0.374 6(2) nm, Symmetry code: A: x+1, y, z) and interchain (N2/C14-C18 and C2B-C7B, Cg…Cg 0.352 1(2) nm, Symmetry code: B: x+1/2, -y+1/2, z+1/2) π-π stacking interactions between adjacent pyridyl planes of the 2, 2′-bipy ligands and the benzene planes of BIPA^2- blocks are observed (Fig. 5). The chains are further extended into a 2D sheet by π-π stacking interactions (Fig. 5).

  Figure 3

  

  Figure 3.  Drawing of asymmetric unit of compound 2 with 30% probability thermal ellipsoids

  H atoms and lattice water molecules were omitted for clarity except H of OH-group; Symmetry codes: A: x+1, y, z; B:-x+1, -y, -z+1; C:-x+2, -y, -z+1

  下载: 全尺寸图片 幻灯片

  Figure 4

  

  Figure 4.  One-dimensional chain viewed along c axis in 2

  Symmetry codes: A:-x+2, -y, -z; B: x-1, y, z; C: -x+1, -y, -z+1; D: x+1, y, z; E: -x+3, -y, -z+1

  下载: 全尺寸图片 幻灯片

  Figure 5

  

  Figure 5.  Two-dimensional sheet viewed along c axis in 2

  Dashed lines present the π-π stacking interactions

  下载: 全尺寸图片 幻灯片

  2.2   TGA analysis

  To determine the thermal stability of compounds 1 and 2, their thermal behaviors were investigated under nitrogen atmosphere by thermogravimetric analysis (TGA). As shown in Fig. 6, compound 1 lost its one lattice and two coordinated water molecules in a range of 43~122 ℃ (Obsd. 10.1%; Calcd. 10.4%), followed by the decomposition at 234 ℃. The TGA curve of 2 reveals that compound 2 was stable up to 241 ℃, then was decomposed upon further heating.

  Figure 6

  

  Figure 6.  TGA curves of compounds 1 and 2

  下载: 全尺寸图片 幻灯片

  2.3   Magnetic properties

  Variable-temperature magnetic susceptibility studies were carried out on powder sample of 2 in a temperature range of 2~300 K (Fig. 7). The χ_MT value at 300 K was 1.20 cm³·mol^-1·K, which is slightly higher than the value (1.125 cm³·mol^-1·K) expected for three magnetically isolated Cu(Ⅱ) centers (S_Cu=1/2, g=2.0). Upon cooling, the χ_MT value decreased to reach a plateau around 11~7 K with χ_MT value of 0.608~0.598 cm³·mol^-1·K, and finally went down to 0.406 cm³·mol^-1·K at 2 K. The plateau corresponds to the ground state (S=1/2). In the 15~300 K interval, the χ_M^-1 vs T plot for 2 obeys the Curie-Weiss law with a Weiss contant θ of -25.3 K and a Curie constant C of 1.26 cm³·mol^-1·K. Although the separation between the adjacent Cu₃ subunits are somewhat longer, the magnetic exchange coupling mediated by spin-polarization mechanism through the intrachain and interchain π-π stacking interactions^[26-28]. Because the magnetic exchange coupling through π-π stacking interactions is assumed to be weaker than the intratrinuclear interactions, the negative value of θ and the decrease in χ_MT should be attributed to the overall antiferromagnetic coupling between the Cu(Ⅱ) ions within the Cu₃ subunit.

  Figure 7

  

  Figure 7.  Temperature dependence of χ_MT (○) and 1/χ_M(□) vs T for compound 2

  Red curve represents the best fit to the equations in the text, and the blue line shows the Curie-Weiss fitting

  下载: 全尺寸图片 幻灯片

  The spin Hamiltonian appropriate for describing the magnetic properties of an isolated linear trinuclear system is given in Eq.(1):

  $ {H_{\exp }} = - 2J\left( {{S_1}{S_2} + {S_2}{S_3}} \right) - 2J'\left( {{S_1}{S_3}} \right) $

  (1)

  Where J denotes the exchange parameter between the central and terminal copper(Ⅱ) ions, and J′ is assumed to be zero since the distance between the two terminal Cu(Ⅱ) ions is so large (0.688 3 nm). The magnetic properties were analyzed using Eq.(2), derived from Eq.(1) for a linear trinuclear model with S=1/2^[29]:

  $ {\chi _{\rm{M}}} = \frac{{N{g^2}{\beta ^2}}}{{3k\left( {T - \theta } \right)}}\frac{{\left( {1 + {{\rm{e}}^{ - \frac{{2J}}{{kT}}}} + 10{{\rm{e}}^{^{ - \frac{{2J}}{{kT}}}}}} \right)}}{{\left( {1 + {{\rm{e}}^{ - \frac{{2J}}{{kT}}}} + 2{{\rm{e}}^{^{ - \frac{{2J}}{{kT}}}}}} \right)}}{N_\alpha } $

  (2)

  Where θ is a Weiss-like correction for intermolecular interactions, and N_α is temperature independent para-magnetism. Using this method, the susceptibilities for 2 above 15.0 K were simulated, and the best-fit parameters for 2 were obtained: J=-35.6 cm^-1, g=2.11, θ=-0.47 K, N_α=3.60×10^-4 cm³·mol^-1 and R=5.2×10^-5, where R=∑(T_obs-T_calc)²/∑(T_obs)². The J value of -35.6 cm^-1 indicates that the coupling between the adjacent Cu(Ⅱ) centers is antiferromagnetic. According to the structure of compound 2, there are two sets of magnetic exchange pathways within the trinuclear copper(Ⅱ) cores, namely, via the μ-OH^- groups and μ-carboxylates bridges (Fig. 4), which can be responsible for the observed antiferromagnetic exchange.

  3.   Conclusions

  In summary, we have synthesized two Cu(Ⅱ) coordination compounds whose structures depend on the molar ratio between NaOH and H₂BIPA. This work demonstrates that the molar ratio between NaOH and carboxylic acid ligand has a significant effect on the structures of Cu(Ⅱ) coordination compounds.

  
  
• 1. [1]

     Lu W G, Su C Y, Lu T B, et al. J. Am. Chem. Soc., 2006, 128:34-35 doi: 10.1021/ja0567337

  2. [2]

     Zhen X D, Lu T B. CrystEngComm, 2010, 12:324-336 doi: 10.1039/B911991D

  3. [3]

     Gu J Z, Wen M, Cai Y, et al. Inorg. Chem., 2019, 58:2403-2412 doi: 10.1021/acs.inorgchem.8b02926

  4. [4]

     Gu J Z, Wen M, Cai Y, et al. Inorg. Chem., 2019, 58:5875-5885 doi: 10.1021/acs.inorgchem.9b00242

  5. [5]

     Jain P, Ramachandran V, Clark R J, et al. J. Am. Chem. Soc., 2009, 131:13625-13627 doi: 10.1021/ja904156s

  6. [6]

     Minguez E G, Coronado E. Chem. Soc. Rev., 2018, 47:533-557 doi: 10.1039/C7CS00653E

  7. [7]

     Cui Y J, Yue Y F, Qian G D, et al. Chem. Rev., 2012, 112:1126-1162 doi: 10.1021/cr200101d

  8. [8]

     Zhao J, Wang Y N, Dong W W, et al. Inorg. Chem., 2016, 55:3265-3271 doi: 10.1021/acs.inorgchem.5b02294

  9. [9]

     Zhu J, Usov P M, Xu W Q, et al. J. Am. Chem. Soc., 2018, 140:993-1003 doi: 10.1021/jacs.7b10643

  10. [10]

      Fu H R, Zhao Y, Zhou Z, et al. Dalton Trans., 2018, 47:3725-3732 doi: 10.1039/C8DT00206A

  11. [11]

      Gu J Z, Liang X X, Cai Y, et al. Dalton Trans., 2017, 46:10908-10925 doi: 10.1039/C7DT01742A

  12. [12]

      Gu J Z, Liang X X, Cui Y H, et al. CrystEngComm, 2017, 19:117-128 doi: 10.1039/C6CE02115H

  13. [13]

      Ma D Y, Qin L, Lei J M, et al. CrystEngComm, 2016, 18:1363-1375 doi: 10.1039/C5CE02314A

  14. [14]

      Mao N N, Hu P, Yu F, et al. CrystEngComm, 2017, 19:4586-4594 doi: 10.1039/C7CE00808B

  15. [15]

      Gu J Z, Cai Y, Qian Z Y, et al. Dalton Trans., 2018, 47:7431-7444 doi: 10.1039/C8DT01299G

  16. [16]

      Gu J Z, Gao Z Q, Tang Y. Cryst. Growth Des., 2012, 12:3312-3323 doi: 10.1021/cg300442b

  17. [17]

      邹训重, 吴疆, 顾金忠, 等.无机化学学报, 2019, 35(9):1705-1711 doi: 10.11862/CJIC.2019.190ZOU Xun-Zhong, WU Jiang, GU Jin-Zhong, et al. Chinese J. Inorg. Chem., 2019, 35(9):1705-1711 doi: 10.11862/CJIC.2019.190

  18. [18]

      Gu J Z, Cui Y H, Liang X X, et al. Cryst. Growth Des., 2016, 16:4658-4670 doi: 10.1021/acs.cgd.6b00735

  19. [19]

      Peng Y W, Wu R J, Liu M, et al. Cryst. Growth Des., 2019, 19:1322-1328 doi: 10.1021/acs.cgd.8b01709

  20. [20]

      顾文君, 顾金忠.无机化学学报, 2017, 33(2):227-236 doi: 10.11862/CJIC.2017.035GU Wen-Jun, GU Jin-Zhong. Chinese J. Inorg. Chem., 2017, 33(2):227-236 doi: 10.11862/CJIC.2017.035

  21. [21]

      赵素琴, 顾金忠.无机化学学报, 2016, 32(9):1611-1618 doi: 10.11862/CJIC.2016.203ZHAO Su-Qin, GU Jin-Zhong. Chinese J. Inorg. Chem., 2016, 32(9):1611-1618 doi: 10.11862/CJIC.2016.203

  22. [22]

      Gu J Z, Liang X X, Cai Y, et al. Dalton Trans., 2017, 46:10908-10925 doi: 10.1039/C7DT01742A

  23. [23]

      Spek A L. Acta Crystallogr. Sect. C:Struct. Chem., 2015, C71:9-18

  24. [24]

      Addison A W, Rao T N, Reedijk J, et al. J. Chem. Soc. Dalton Trans., 1984, 7:1349-1356

  25. [25]

      Dey S K, Shit S, Mitra S, et al. Inorg. Chim. Acta, 2007, 360:1915-1920 doi: 10.1016/j.ica.2006.09.030

  26. [26]

      Spielberg E T, Fittipaldi M, Geibig D, et al. Inorg. Chim. Acta, 2010, 363:4269-4276 doi: 10.1016/j.ica.2010.08.017

  27. [27]

      Fernandes T S, Vilela R S, Valdo A K, et al. Inorg. Chem., 2016, 55:2390-2401 doi: 10.1021/acs.inorgchem.5b02786

  28. [28]

      Glaser T, Heidemeier M, Strautmann J B H, et al. Chem. Eur. J., 2007, 13:9191-9206 doi: 10.1002/chem.200700781

  29. [29]

      Bonner J C, Fisher M E. Phys. Rev. A, 1964, 135:640-658 doi: 10.1103/PhysRev.135.A640

• 

  Figure 1  Drawing of asymmetric unit of compound 1 with 30% probability thermal ellipsoids

  H atoms and lattice water molecules were omitted for clarity

  下载: 全尺寸图片 幻灯片
  

  Scheme 1  Coordination modes of BIPA2- ligands in compounds 1 and 2

  下载: 全尺寸图片 幻灯片
  

  Figure 2  Perspective of 2D sheet in 1

  Dashed lines present the H-bonds

  下载: 全尺寸图片 幻灯片
  

  Figure 3  Drawing of asymmetric unit of compound 2 with 30% probability thermal ellipsoids

  H atoms and lattice water molecules were omitted for clarity except H of OH-group; Symmetry codes: A: x+1, y, z; B:-x+1, -y, -z+1; C:-x+2, -y, -z+1

  下载: 全尺寸图片 幻灯片
  

  Figure 4  One-dimensional chain viewed along c axis in 2

  Symmetry codes: A:-x+2, -y, -z; B: x-1, y, z; C: -x+1, -y, -z+1; D: x+1, y, z; E: -x+3, -y, -z+1

  下载: 全尺寸图片 幻灯片
  

  Figure 5  Two-dimensional sheet viewed along c axis in 2

  Dashed lines present the π-π stacking interactions

  下载: 全尺寸图片 幻灯片
  

  Figure 6  TGA curves of compounds 1 and 2

  下载: 全尺寸图片 幻灯片
  

  Figure 7  Temperature dependence of χ_MT (○) and 1/χ_M(□) vs T for compound 2

  Red curve represents the best fit to the equations in the text, and the blue line shows the Curie-Weiss fitting

  下载: 全尺寸图片 幻灯片

  Table 1.  Crystal data for compounds 1 and 2

  Compound	1	2
  Chemical formula	C18H17BrCuN2O7	C36H24Br2Cu3N4O10
  Molecular weight	516.78	1 023.03
  Crystal system	Monoclinic	Monoclinic
  Space group	P21/c	P21/n
  a / nm	2.062 7(2)	0.985 21(4)
  b / nm	0.783 37(5)	1.741 02(7)
  c / nm	2.374 67(17)	1.030 43(7)
  β / (°)	91.907(7)	99.378(5)
  V / nm3	3.835 0(5)	1.743 84(16)
  Z	8	2
  F(000)	2 072	1 010
  θ range for data collection / (°)	3.286~25.050	3.538~25.044
  Limiting indices	-24 ≤ h ≤ 24, -9 ≤ k ≤ 8, -28 ≤ l ≤ 22	-9 ≤ h ≤ 11, -18 ≤ k ≤ 20, -11 ≤ l ≤ 12
  Reflection collected, unique (Rint)	13 849, 6 782 (0.082 2)	5 731, 3 084 (0.033 4)
  Dc / (g·cm-3)	1.790	1.948
  μ / mm-1	3.268	4.172
  Data, restraint, parameter	6 782, 0, 523	3 084, 0, 254
  Goodness-of-fit on F2	1.000	1.048
  Final R indices [I≥2σ(I)] R1, wR2	0.060 8, 0.084 7	0.041 7, 0.093 7
  R indices (all data) R1, wR2	0.116 4, 0.146 7	0.061 8, 0.107 2
  Largest diff. peak and hole / (e·nm-3)	915 and -534	1 234 and -708

  下载: 导出CSV

  Table 2.  Selected bond lengths (nm) and bond angles (°) for compounds 1 and 2

  1
  Cu(1)-O(2)	0.197 1(5)	Cu(1)-O(9)	0.197 1(5)	Cu(1)-O(10)	0.223 6(5)
  Cu(1)-N(1)	0.200 2(7)	Cu(1)-N(2)	0.200 3(6)	Cu(2)-O(5)	0.197 2(5)
  Cu(2)-O(11)	0.224 2(4)	Cu(2)-O(12)	0.195 7(5)	Cu(2)-N(3)	0.202 6(6)
  Cu(2)-N(4)	0.200 7(6)
  O(9)-Cu(1)-O(2)	93.6(2)	O(9)-Cu(1)-N(1)	93.3(2)	O(2)-Cu(1)-N(1)	168.4(3)
  O(9)-Cu(1)-N(2)	164.4(2)	O(2)-Cu(1)-N(2)	90.6(3)	N(2)-Cu(1)-N(1)	80.3(3)
  O(9)-Cu(1)-O(10)	90.96(19)	O(2)-Cu(1)-O(10)	96.7(2)	N(1)-Cu(1)-O(10)	92.5(2)
  N(2)-Cu(1)-O(10)	103.5(2)	O(5)-Cu(2)-O(12)	94.0(2)	O(12)-Cu(2)-N(4)	165.1(2)
  O(5)-Cu(2)-N(4)	90.0(2)	O(12)-Cu(2)-N(3)	93.8(2)	O(5)-Cu(2)-N(3)	168.0(2)
  N(4)-Cu(2)-N(3)	80.3(3)	O(12)-Cu(2)-O(11)	91.90(19)	O(11)-Cu(2)-O(5)	98.40(19)
  N(4)-Cu(2)-O(11)	101.8(2)	N(3)-Cu(2)-O(11)	90.4(2)
  2
  Cu(1)-O(1)	0.193 0(3)	Cu(1)-O(3)A	0.264 9(4)	Cu(1)-O(5)	0.190 2(4)
  Cu(1)-N(1)	0.200 1(4)	Cu(1)-N(2)	0.202 2(4)	Cu(2)-O(4)A	0.195 2(3)
  Cu(2)-O(4)B	0.195 2(3)	Cu(2)-O(5)	0.192 2(4)	Cu(2)-O(5)C	0.192 2(4)
  O(5)-Cu(1)-O(1)	97.96(15)	O(5)-Cu(1)-N(1)	92.83(16)	O(1)-Cu(1)-N(1)	164.80(16)
  O(5)-Cu(1)-N(2)	169.39(16)	O(1)-Cu(1)-N(2)	90.64(14)	N(1)-Cu(1)-N(2)	79.96(15)
  O(1)-Cu(1)-O(3)A	100.94(15)	O(5)-Cu(1)-O(3)A	79.77(14)	N(1)-Cu(1)-O(3A)	91.46(15)
  N(2)-Cu(1)-O(3A)	92.57(15)	O(5)-Cu(2)-O(4)A	91.76(14)	O(5)-Cu(2)-O(4)B	88.24(14)
  Symmetry codes: A: x+1, y, z; B: -x+1, -y, -z+1; C: -x+2, -y, -z+1 for 2.

  下载: 导出CSV

  Table 3.  Hydrogen bond parameters of compounds 1 and 2

  Compound	D-H…A	d(D-H) / nm	d(H…A) / nm	d(D…A) / nm	∠DHA / (°)
  1	O(9)-H(1W)…O(1)	0.087 6	0.178 1	0.256 0	147.0
  	O(9)-H(2W)…O(7)A	0.087 7	0.181 1	0.266 9	165.3
  	O(10)-H(3W)…O(8)A	0.086 8	0.193 7	0.279 8	171.2
  	O(10)-H(4W)…O(7)B	0.085 0	0.183 1	0.268 1	179.1
  	O(11)-H(5W)…O(4)C	0.086 1	0.197 0	0.269 3	140.9
  	O(11)-H(6W)…O(3)D	0.085 0	0.195 9	0.280 9	179.5
  	O(12)-H(7W)…O(4)D	0.085 0	0.185 7	0.270 7	179.1
  	O(12)-H(8W)…O(6)	0.087 4	0.178 5	0.255 6	145.8
  	O(13)-H(9W)…O(8)A	0.085 0	0.204 4	0.289 4	179.1
  	O(14)-H(11W)…O(3)E	0.085 0	0.196 8	0.281 6	175.3
  2	O(5)-H(1)…O(2)	0.076 0	0.215 1	0.281 6	146.5
  Symmetry codes: A: -x, y+1/2, -z+1/2; B: x, y+1, z; C: x, y-1, z; D: -x+1, y-1/2, -z+1/2; E: -x+1, y+1/2, -z+1/2 for 1.

  下载: 导出CSV
•