English

• 0   Introduction

  In the past decades, a considerable attention was focused on the crystal engineering of metal-organic and supramolecular architectures based on different carboxylic acid building blocks and assembled by covalent bonds and various non-covalent forces (strong and weak hydrogen bonds, π-π interactions, and halogen bonding)^[1-6]. This research was primarily justified by a diversity of applications of the obtained compounds that span from gas sorption, magnetism, sensing and molecular recognition to photochemistry, catalysis, and medicinal chemistry^[7-15].

  As is well known, many factors may seriously influence the structures of the resulting compounds, such as the ligands, kinds of metal salt, the solvent system, pH value, the metal-to-ligand ratio, reaction temperature and time, and so on^[16-20]. Multicarboxylate ligands are often employed as bridging blocks to construct coordination compounds due to their versatile coordination modes and the ability to act as H-bond acceptors and donors to assemble supramol-ecular structures^[21-26]. In order to extend our research in this field, we have selected biphenyl-2, 4, 4′-tricarboxylic acid (H₃btc) as a functional building block on account of the following considerations: (a) H₃btc possesses three carboxyl groups that may be completely or partially deprotonated, depending on pH value; (b) it is a flexible ligand allowing the rotation of two phenyl rings around the C-C single bond; (c) to our knowledge, H₃btc has not been adequately explored in the construction of coordination polymers^[21-22].

  Taking into account these factors, we herein report the syntheses, crystal structures, magnetic properties of Mn(Ⅱ) and Ni(Ⅱ) coordination compounds constructed from Hbtc^2- and phen 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 the 2~300 K temperature range 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 [Mn₂(Hbtc)₂(phen)₄]·5H₂O (1)

  A mixture of MnCl₂·4H₂O (0.060 g, 0.3 mmol), H₃btc (0.086 g, 0.3 mmol), phen (0.120 g, 0.6 mmol), NaOH (0.024 g, 0.6 mmol), and H₂O (10 mL) was stirred at room temperature for 15 min, and then sealed in a 25 mL Teflon-lined stainless steel vessel, and heated at 160 ℃ for 3 days, followed by cooling to room temperature at a rate of 10 ℃·h^-1. Yellow block-shaped crystals of 1 were isolated manually, and washed with distilled water. Yield: 63% (based on Mn salt). Anal. Calcd. for C₇₈H₅₈Mn₂N₈O₁₇(%): C 62.91, H 3.92, N 7.52; Found(%): C 62.78, H 3.95, N 7.61. IR (KBr, cm^-1): 3 394m, 3 060m, 1 700m, 1 572s, 1 516m, 1 424s, 1 372s, 1 344m, 1 262m, 1 170w, 1 142w, 1 102 m, 1 050w, 1 004w, 912w, 850m, 774s, 734s, 682m, 660w, 630w, 550w.

  1.3   Synthesis of [Ni₂(Hbtc)₂(phen)₄]·2H₃btc·4H₂O(2)

  A mixture of NiCl₂·6H₂O (0.071 g, 0.3 mmol), H₃btc (0.172 g, 0.6 mmol), phen (0.120 g, 0.6 mmol), NaOH (0.024 g, 0.6 mmol), and H₂O (10 mL) was stirred at room temperature for 15 min, and then sealed in a 25 mL Teflon-lined stainless steel vessel, and heated at 160 ℃ for 3 days, followed by cooling to room temperature at a rate of 10 ℃·h^-1. Purple needle-shaped crystals of 2 were isolated manually, and washed with distilled water. Yield: 65% (based on Ni salt). Anal. Calcd. for C₁₀₈H₇₆Ni₂N₈O₂₈(%): C 62.24, H 3.73, N 5.46; Found(%): C 62.41, H 3.71, N 5.49. IR (KBr, cm^-1): 3 573w, 3 428w, 1 683s, 1 585s, 1 517m, 1 423s, 1 382w, 1 367w, 1 304w, 1 278w, 1 231m, 1 180 w, 1 154w, 1 086w, 1 003w, 925w, 910w, 868w, 848w, 811w, 769w, 728w, 676w, 655w, 645w, 531w.

  1.4   Structure determination

  Single-crystal data of 1 and 2 were collected at 293(2) K on a Bruker APE-Ⅱ CCD diffractometer with Mo Kα radiation (λ=0.071 073 nm). The crystallogra-phic data are summarized in Table 1. The selected bond lengths and angles are listed in Table 2. Hydrogen bond parameters of the compounds 1 and 2 are given in Tables 3 and 4. The structure was solved using direct methods, which yielded the positions of all non-hydrogen atoms. These were refined first isotropically and then anisotropically. All the hydrogen atoms (except for those bound to water molecules) were placed in calculated positions with fixed isotropic thermal parameters and included in structure factor calculations at the final stage of full-matrix least-squares refinement. The hydrogen atoms of the water molecules were located by difference maps and cons-trained to ride on their parent O atoms. All calcula-tions were performed using the SHELXL program^[27].

  Table 1.  Crystal data for compounds 1 and 2

  表选项

  导出Excel

  下载全尺寸表图像

  Compound	1	2
  Chemical formula	C78H58Mn2N8O17	C108H76Ni2N8O28
  Molecular weight	1 489.20	2 051.19
  Crystal system	Triclinic	Triclinic
  Space group	P1	p1
  a / nm	1.384 52(13)	1.221 50(9)
  b / nm	1.40M 38(8)	1.385 16(10)
  c / nm	2.006 02(17)	1.467 12(10)
  α / (°)	93.116(6)	67.698(7)
  β / (°)	109.822(8)	86.452(6)
  γ / (°)	103.188(6)	77.217(6)
  V / nm3	3.538 0(5)	2.239 0(3)
  Z	2	1
  F(000)	1 536	1 060
  Crystal size / mm	0.30×0.30×0.18	0.27×0.24×0.23
  θ range for data collection / (°)	3.02～25.05	3.31～25.05
  Limiting indices	-15 ≤ h ≤ 16, -16 ≤ k ≤ 16, -23 ≤ l ≤ 23	-14 ≤ h ≤ 14, -16 ≤ k ≤ 16, -17 ≤ l ≤ 17
  Reflections collected, unique (Rint)	26 653, 12 332 (0.060 8)	14 229, 7 939 (0.027 6)
  Dc (g·cm-3)	1.398	1.521
  μ / mm-1	0.434	0.513
  Data, restraints, parameters	12 332, 114, 948	7 939, 1, 674
  Goodness-of-fit on F2	0.963	1.007
  R1, wR2 [I≥2σ(I)]	0.069 7, 0.152 7	0.043 9, 0.090 4
  R1, wR2 (all data)	0.127 3, 0.186 6	0.053 4, 0.096 6
  Largest diff. peak and hole / (e·nm-3)	400 and -381	1 089 and -635

  Table 2.  Selected bond distances (nm) and bond angles (°) for

  表选项

  导出Excel

  下载全尺寸表图像

  1
  Mn(1)-O(1)	0.210 0(4)	Mn(1)-O(4)A	0.210 4(3)	Mn(1)-N(1)	0.227 4(4)
  Mn(1)-N(2)	0.239 7(4)	Mn(1)-N(3)	0.232 5(4)	Mn(1)-N(4)	0.226 7(4)
  Mn(2)-O(9)	0.212 5(3)	Mn(2)-O(10)B	0.215 4(3)	Mn(2)-N(5)	0.225 5(5)
  Mn(2)-N(6)	0.232 6(4)	Mn(2)-N(7)	0.226 3(4)	Mn(2)-N(8)	0.227 8(4)
  O(1)-Mn(1)-O(4)A	100.10(14)	O(1)-Mn(1)-N(4)	112.46(15)	0(4)A-Mn(1)-N(4)	91.69(12)
  O(1)-Mn(1)-N(1)	87.92(18)	0(4)A-Mn(1)-N(1)	103.85(13)	N(4)-Mn(1)-N(1)	151.98(16)
  O(1)-Mn(1)-N(3)	88.92(14)	0(4)A-Mn(1)-N(3)	163.88(13)	N(4)-Mn(1)-N(3)	72.44(14)
  N(1)-Mn(1)-N(3)	89.70(14)	O(1)-Mn(1)-N(2)	158.33(17)	0(4)A-Mn(1)-N(2)	90.35(13)
  N(4)-Mn(1)-N(2)	85.89(15)	N(1)-Mn(1)-N(2)	71.08(17)	N(3)-Mn(1)-N(2)	85.77(14)
  0(9)-Mn(2)-O(10)B	98.64(12)	0(9)-Mn(2)-N(5)	91.39(14)	0(10)B-Mn(2)-N(5)	90.51(16)
  O(9)-Mn(2)-N(7)	172.46(13)	O(10)B-Mn(2)-N(7)	87.43(13)	N(5)-Mn(2)-N(7)	93.05(15)
  O(9)-Mn(2)-N(8)	100.79(14)	O(10)B-Mn(2)-N(8)	103.58(13)	N(5)-Mn(2)-N(8)	159.62(15)
  N(7)-Mn(2)-N(8)	73.28(15)	O(9)-Mn(2)-N(6)	90.56(14)	O(10)B-Mn(2)-N(6)	161.55(17)
  N(5)-Mn(2)-N(6)	73.2(2)	N(7)-Mn(2)-N(6)	84.89(14)	N(8)-Mn(2)-N(6)	90.24(18)
  2
  Ni(1)-O(1)	0.208 3(2)	Ni(1)-O(2)A	0.205 9(2)	Ni(1)-N(1)	0.208 O(2)
  Ni(1)-N(2)	0.210 4(2)	Ni(1)-N(3)	0.206 8(2)	Ni(1)-N(4)	0.208 6(2)
  O(2)A-Ni(1)-N(3)	97.32(8)	O(2)A-Ni(1)-N(1)	86.43(8)	N(3)-Ni(1)-N(1)	172.03(9)
  O(2)A-Ni(1)-O(1)	88.93(7)	N(3)-Ni(1)-O(1)	97.6O(8)	N(1)-Ni(1)-O(1)	89.47(8)
  O(2)A-Ni(1)-N(4)	175.73(8)	N(3)-Ni(1)-N(4)	80.07(8)	N(1)-Ni(1)-N(4)	95.75(8)
  O(1)-Ni(1)-N(4)	94.76(8)	O(2)A-Ni(1)-N(2)	86.26(8)	N(3)-Ni(1)-N(2)	93.22(8)
  N(1)-Ni(1)-N(2)	79.97(9)	O(1)-Ni(1)-N(2)	168.64(8)	N(4)-Ni(1)-N(2)	90.5O(8)
  Symmetry codes: A: -x, -y+1, -z+1; B: -x, -y+2, -z+2 for 1; A: -x+1, -y+1, -z for 2.

  CCDC: 1456513, 1; 1456514, 2.

  2   Results and discussion

  2.1   Description of the structures

  2.2   TGA analysis

  The thermal stability of 1 and 2 was investigated under nitrogen atmosphere by thermogravimetric analysis (TGA); the obtained plots are shown in Fig. 7. Compound 1 loses its five lattice water molecules (Found 5.85%; Calcd. 6.04%) in the 28~116 ℃ range, followed by the decomposition starting at 205 ℃. For 2, there are two distinct thermal effects in the 98~238 ℃ range that correspond to the removal of four free H₂O molecules (Found 3.45%; Calcd. 3.51%) and two co-crystallization H₃btc molecules (Found 32.1%; Calcd. 31.5%), followed by the concomitant decomposition.

  Figure 7.  TGA curves of compounds 1 and 2

  图选项

  下载全尺寸图像

  下载幻灯片

  2.3   Magnetic properties

  Variable-temperature magnetic susceptibility studies were carried out on powder samples of 1 and 2 in the 2~300 K temperature range. For 1, the χ_MT value at 300 K is 8.81 cm³·mol^-1·K, which is close to the value of 8.76 cm³·mol^-1·K expected for two magnetically isolated high-spin Mn(Ⅱ) centers (S_Mn=5/2, g=2.0). Upon cooling, the χ_MT value drops down very slowly from 8.81 cm³·mol^-1·K at 300 K to 8.38 cm³·mol^-1·K at 98 K and then decreases steeply to 1.50 cm³·mol^-1·K at 2 K (Fig. 8). The χ_M^-1 vs T plot for 1 in the 2~300 K interval obeys the Curie-Weiss law with a Weiss constant θ of -10.40 K and a Curie constant C of 9.10 cm³·mol^-1·K. The negative value of θ and the decrease of the χ_MT should be attributed to the overall antiferromagnetic coupling between the Mn(Ⅱ) centers within the Mn₂ unit. We tried to fit the magnetic data of 1 using the following expression^[29-30] for the dinuclear Mn(Ⅱ) unit:

  Figure 8.  Temperature dependence of χ_MT (○) and 1/χ_M (□) vs T for compound 1

  图选项

  下载全尺寸图像

  下载幻灯片

  Least-squares analysis of magnetic susceptibility data led to J=-3.82 cm^-1, g=2.00 and R=3.46×10^-5. These values confirm the presence of antiferromagnetic interaction between the Mn(Ⅱ) ions within the dinu-clear units. Because of the long separation within the dinuclear Mn₂ unit Ⅰ (0.810 0(4) nm), the negative value of J should be attributed to the antiferromagnetic coupling between the Mn(Ⅱ) atoms within the Mn₂ unit Ⅱ.

  For 2, the χ_MT value at 300 K is 2.18 cm³·mol^-1·K, which is higher than the spin only value of 2.00 cm³·mol^-1·K for two magnetically isolated Ni(Ⅱ) center (S_Ni=1, g=2.0). Upon cooling, the χ_MT value drops down very slowly from 2.18 cm³·mol^-1·K at 300 K to 2.11 cm³·mol^-1·K at 96 K, and then decreases steeply to 0.73 cm³·mol^-1·K at 2 K (Fig. 9). In the 2~300 K interval, the χ_M^-1 vs T plot for 2 obeys the Curie-Weiss law with a Weiss constant θ of -6.58 K and a Curie constant C of 2.11 cm³·mol^-1·K, suggesting a weak antiferromagnetic interaction between the Ni(Ⅱ) ions.

  Figure 9.  Temperature dependence of χ_MT (○) and 1/χ_M (□) vs T for compound 2

  图选项

  下载全尺寸图像

  下载幻灯片

  We tried to fit the magnetic data of 2 using the following expression^[31] for a dinuclear Ni(Ⅱ) unit:

  where ρ is a paramagnetic impurity fraction and TIP is temperature independent paramagnetism. Using this model, the susceptibility for 2 above 2.0 K was simulated, leading to the values of J=-2.35 cm^-1, g=2.09, ρ=0.011, and TIP=4.56×10^-6 cm³·mol^-1, with the agreement factor R=7.57×10^-4 (R=∑(T_obs-T_calc)²/∑T_obs²). The negative J parameter confirms that a weak antif-erromagnetic exchange coupling exists between the adjacent Ni(Ⅱ) centers, which is in agreement with a negative θ value. In compounds 1 and 2, there is one type of the magnetic exchange pathway within the dinuclear Mn₂ and Ni₂ units, namely via double μ₂-η¹:η¹-carboxylate (syn-syn) bridges (Fig. 1 and 5).

  2.1.2   [Ni₂(Hbtc)₂(phen)₄]·2H₃btc·4H₂O(2)

  In complex 2, the asymmetric unit consists of one Ni(Ⅱ) atom, one Hbtc^2- block, two lattice water molecules, and a molecule of co-crystallized H₃btc (Fig. 4). The six-coordinate Ni1 center is bound by four N atoms from two phen ligands and two carboxylate O atoms from two different Hbtc^2- blocks, thus forming an octahedral {NiN₄O₂} geometry. The Ni-O bonds are in the range of 0.205 9(2)~0.208 3(2) nm, while the Ni-N distances vary from 0.206 8(2)~0.210 4(2) nm; all these distances are comparable to those found in the reported Ni(Ⅱ) compounds^{[21-22, 26, 28]}. In 2, two crystallographically equal Ni1 centers are bridged by 2-carboxylate groups of two different Hbtc^2- blocks, giving rise to a dinuclear Ni₂ unit with a Ni…Ni separation of 0.479 8(4) nm (Fig. 5). Obviously, the Ni₂ dinuclear unit and the Mn₂ dinuclear unit Ⅱ in 1 are isostructural. The dihedral angle of two benzene rings in the Hbtc^2- and H₃btc are 45.80° and 35.07°, respe-ctively. The discrete Ni₂ units and free H₃btc molecules are interlinked by the strong O-H…O hydrogen bonds to form a 3D supramolecular framework (Fig. 6, Table 4).

  Figure 4.  Drawing of the asymmetric unit of compound 2 with 30% probability thermal ellipsoids

  图选项

  下载全尺寸图像

  下载幻灯片

  Figure 5.  Dinuclear Ni2 unit in compound 2

  图选项

  下载全尺寸图像

  下载幻灯片

  Figure 6.  Perspective view of 3D supramolecular structure in the ac plane

  图选项

  下载全尺寸图像

  下载幻灯片

  Table 4.  Hydrogen bond lengths (nm) and angles (°) of compound 2

  表选项

  导出Excel

  下载全尺寸表图像

  D-H…A	d(D-H)	d(H…A)	d(D…A)	∠DHA
  O(3)-H⑴…O(6)A	0.082	0.179	0.260 6	172.2
  O(7)-H(2)…O(5)B	0.082	0.177	0.258 3	170.4
  O(10)-H(4)…O(12)C	0.082	0.180	0.261 8	172.8
  O(11)-H(5)…O(9)A	0.084	0.177	0.261 3	175.0
  O(13)-H(1W)…O(6)B	0.092	0.198	0.290 4	174.0
  O(13)-H(2W)…O(14)E	0.073	0.212	0.283 0	166.0
  O(14)-H(3W)…O(13)D	0.085	0.197	0.282 2	179.7
  O(14)-H(4W)…O(8)B	0.085	0.213	0.298 3	179.7
  Symmetry codes: A: x, y-1, z; B: -x+1, -y+1, -z+1; C: x, y+1, z; D: -x+2, -y+1, -z+1; E: x, y-1, z+1.

  2.1.1   [Mn₂(Hbtc)₂(phen)₄]·5H₂O(1)

  The X-ray crystallography analysis reveals that the compound 1 crystallizes in the triclinic system space group P1. The asymmetric unit of compound 1 contains two crystallographically unique Mn(Ⅱ) atoms, two Hbtc^2- ligands, four phen moieties, and five lattice water molecules. The partial deprotonation of H₃btc to give Hbtc^2- is also confirmed by the IR spectral data of 1, since a band -COOH band at 1 700 cm^-1 was observed (Experimental Section). As depicted in Fig. 1, both Mn1 and Mn2 atoms are six-coordinated by two carboxylate O atoms of two independent Hbtc^2- ligands and four N atoms of two phen moieties, forming a distorted octahedral geometry. The Mn-O (0.210 0(4)~0.215 4(3) nm) and Mn-N (0.225 5(5)~0.239 7(4) nm) bond lengths are in good agreement with those distances observed in some other Mn(Ⅱ)compounds^{[17, 21, 23-24]}. As shown in Fig. 2, two crystallo-graphically equal Mn1 centers are bridged by 2-and 4-carboxylate groups of two different Hbtc^2- blocks, giving rise to a dinuclear unit Ⅰ with a Mn…Mn separation of 0.810 0(4) nm. Simultaneously, 2-carbo-xylate groups of two different Hbtc^2- blocks bridge two crystallographically equal Mn2 centers to form another dinuclear unit Ⅱ with a Mn…Mn separation of 0.427 9(4) nm. Obviously, dinuclear Mn2 units Ⅰ and Ⅱ are isomers. The dihedral angles of two benzene rings in the Hbtc^2- blocks are 45.04° and 63.97°, respectively. These dinuclear Mn₂ units are further extended into the 3D supramolecular frameworks through O-H…O hydrogen bonding (Fig. 3 and Table 3).

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

  图选项

  下载全尺寸图像

  下载幻灯片

  Figure 2.  Dinuclear Mn2 units Ⅰ and Ⅱ in compound 1

  图选项

  下载全尺寸图像

  下载幻灯片

  Figure 3.  Perspective view of 3D supramolecular structure in the bc plane

  图选项

  下载全尺寸图像

  下载幻灯片

  Table 3.  Hydrogen bond lengths (nm) and angles (°) of compound 1

  表选项

  导出Excel

  下载全尺寸表图像

  D-H…A	d(D-H)	d(H…A)	d(D…A)	∠DHA
  O(6)-H(6)…O(14)C	0.082	0.189	0.262 6	148.4
  O(8)-H(8)…O(12)D	0.082	0.170	0.251 0	171.4
  O(13)-H(13A)…O(14)	0.084	0.224	0.307 3	178.4
  O(13)-H(13B)…O(3)	0.085	0.192	0.276 9	178.6
  O(14)-H(14A)…O(2)A	0.085	0.202	0.286 9	178.7
  O(15)-H(15A)…O(3)	0.085	0.216	0.283 9	136.6
  O(16)-H(16B)…O(7)E	0.085	0.216	0.300 7	179.7
  O(17)-H(17A)…O(13)	0.098	0.213	0.298 5	144.8
  Symmetry codes: A: -x, -y+1, -z+1; B: -x, -y+2, -z+2; C: x-1, y, z; D: x+1, y, z; E: x, y-1, z.

  3   Conclusions

  In summary, two new compounds, namely [Mn₂(Hbtc)₂(phen)₄]·5H₂O (1) and [Ni₂(Hbtc)₂(phen)₄]· 2(H₃btc)·4H₂O (2) have been synthesized under hydrothermal conditions. Both compounds feature the dinuclear structures, which are further extended into the 3D supramolecular frameworks through O-H…O hydrogen bonding. Magnetic studies for two compounds show a weak antiferromagnetic coupling between the adjacent metal centers.

• 1. [1]

     Seoane B, Castellanos S, Dikhtiarenko A, et al. Coord. Chem. Rev., 2016, 307:147-187 doi: 10.1016/j.ccr.2015.06.008

  2. [2]

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

  3. [3]

     Almáši M, Zeleňák V, Zukal A, et al. Dalton Trans., 2016, 45:1233-1242 doi: 10.1039/C5DT02437D

  4. [4]

     Reger D L, Leitner A P, Smith M D. Cryst. Growth Des., 2016, 16:527-536 doi: 10.1021/acs.cgd.5b01575

  5. [5]

     Yin Z, Zhou Y L, Zeng M H, et al. Dalton Trans., 2015, 44: 5258-5275 doi: 10.1039/C4DT04030A

  6. [6]

     Bertani R, Sgarbossa P, Venzo A, et al. Coord. Chem. Rev., 2010, 254:677-695 doi: 10.1016/j.ccr.2009.09.035

  7. [7]

     Kreno L E, Leong K, Farha O K, et al. Chem. Rev., 2012, 112: 1105-1125 doi: 10.1021/cr200324t

  8. [8]

     Horike S, Umeyama D, Kitagawa S. Acc. Chem. Res., 2013, 46:2376-2384 doi: 10.1021/ar300291s

  9. [9]

     Yan Y, Yang S H, Blake A J, et al. Acc. Chem. Res., 2014, 47:296-307 doi: 10.1021/ar400049h

  10. [10]

      DeCoste J B, Peterson G W. Chem. Rev., 2014, 114:5695-5727 doi: 10.1021/cr4006473

  11. [11]

      Chughtai A H, Ahmad N, Younus H A, et al. Chem. Soc. Rev., 2015, 44:6804-6849 doi: 10.1039/C4CS00395K

  12. [12]

      Li X J, Chen X Y, Jiang F L, et al. Chem. Commun., 2016, 52:2277-2280 doi: 10.1039/C5CC09461E

  13. [13]

      Zheng H Q, Zhang Y N, Liu L F, et al. J. Am. Chem. Soc., 2016, 138:962-968 doi: 10.1021/jacs.5b11720

  14. [14]

      Li C, Sun M H, Xu L, et al. CrystEngComm, 2016, 18:596-600 doi: 10.1039/C5CE02074C

  15. [15]

      Zeng M H, Yin Z, Tan Y X, et al. J. Am. Chem. Soc., 2014, 136:4680-4688 doi: 10.1021/ja500191r

  16. [16]

      Li C P, Wu J M, Du M. Chem. Eur. J., 2012, 18:12437-12445 doi: 10.1002/chem.201200909

  17. [17]

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

  18. [18]

      Gu J Z, Wu J, Lv D Y, et al. Dalton Trans., 2013, 42:4822-4830 doi: 10.1039/c2dt32674d

  19. [19]

      Chen L, Gou S H, Wang J Q. J. Mol. Struct., 2011, 991:149-157 doi: 10.1016/j.molstruc.2011.02.018

  20. [20]

      Lu W G, Jiang L, Lu T B. Cryst. Growth Des., 2010, 10:4310-4318 doi: 10.1021/cg100196j

  21. [21]

      Gu J Z, Kirillov A M, Wu J, et al. CrystEngComm, 2013, 15: 10287-10303 doi: 10.1039/c3ce41457d

  22. [22]

      Shao Y L, Cui Y H, Gu J Z, et al. CrystEngComm, 2013, 18: 765-778

  23. [23]

      Shao Y L, Cui Y H, Gu J Z, et al. RSC Adv., 2015, 5:87484-87495 doi: 10.1039/C5RA16580F

  24. [24]

      Zhao Y, Chang X H, Liu G Z, et al. Cryst. Growth Des., 2015, 15:966-974 doi: 10.1021/cg501768f

  25. [25]

      Wang Y S, Zhou Z M. J. Solid State Chem., 2015, 228:117-123 doi: 10.1016/j.jssc.2015.04.026

  26. [26]

      吕东煜, 高竹青, 顾金忠, 等.无机化学学报, 2011, 27(11):2318-2322 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20111139&journal_id=wjhxxbcnLÜ Dong-Yu, GAO Zhu-Qing, GU Jin-Zhong, et al. Chinese J. Inorg. Chem., 2011, 27(11):2318-2322 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20111139&journal_id=wjhxxbcn

  27. [27]

      Sheldrick G M. SHELXL NT, Version 5. 1, Program for Solution and Refinement of Crystal Structures, University of Göttingen, Germany, 1997.

  28. [28]

      高鹏, 邴颖颖, 张玲玲, 等.无机化学学报, 2015, 31(11):2236-2242 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20151119&journal_id=wjhxxbcnGAO Peng, BING Ying-Ying, ZHANG Ling-Ling, et al. Chinese J. Inorg. Chem., 2015, 31(11):2236-2242 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20151119&journal_id=wjhxxbcn

  29. [29]

      Ma L F, Wang L Y, Du M. CrystEngComm, 2009, 11:2593-2596 doi: 10.1039/b914827m

  30. [30]

      Carlin R L. Magnetochemsitry. Berlin: Springer, 1986.

  31. [31]

      Thompson L K, Niel V, Grove H. Polyhedron, 2004, 23:1175-1184 doi: 10.1016/j.poly.2004.01.022

• 

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

  H atoms were omitted for clarity except those of COOH groups

  下载: 全尺寸图片 幻灯片
  

  Figure 2  Dinuclear Mn2 units Ⅰ and Ⅱ in compound 1

  Phen ligands were omitted for clarity; Symmetry codes: A:-x, -y+1, -z+1; B:-x, -y+2, -z+2

  下载: 全尺寸图片 幻灯片
  

  Figure 3  Perspective view of 3D supramolecular structure in the bc plane

  Dashed lines represent the H-bond

  下载: 全尺寸图片 幻灯片
  

  Figure 4  Drawing of the asymmetric unit of compound 2 with 30% probability thermal ellipsoids

  H atoms were omitted for clarity except those of COOH groups

  下载: 全尺寸图片 幻灯片
  

  Figure 5  Dinuclear Ni2 unit in compound 2

  H atoms were omitted for clarity except those of COOH groups; Symmetry codes: A:-x+1, -y+1, -z

  下载: 全尺寸图片 幻灯片
  

  Figure 6  Perspective view of 3D supramolecular structure in the ac plane

  Dashed lines represent the H-bond

  下载: 全尺寸图片 幻灯片
  

  Figure 7  TGA curves of compounds 1 and 2

  下载: 全尺寸图片 幻灯片
  

  Figure 8  Temperature dependence of χ_MT (○) and 1/χ_M (□) vs T for compound 1

  Curve represents the best fit to the equations in the text; Straight line shows the Curie-Weiss fitting

  下载: 全尺寸图片 幻灯片
  

  Figure 9  Temperature dependence of χ_MT (○) and 1/χ_M (□) vs T for compound 2

  Curve represents the best fit to the equations in the text; Straight 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	C78H58Mn2N8O17	C108H76Ni2N8O28
  Molecular weight	1 489.20	2 051.19
  Crystal system	Triclinic	Triclinic
  Space group	P1	p1
  a / nm	1.384 52(13)	1.221 50(9)
  b / nm	1.40M 38(8)	1.385 16(10)
  c / nm	2.006 02(17)	1.467 12(10)
  α / (°)	93.116(6)	67.698(7)
  β / (°)	109.822(8)	86.452(6)
  γ / (°)	103.188(6)	77.217(6)
  V / nm3	3.538 0(5)	2.239 0(3)
  Z	2	1
  F(000)	1 536	1 060
  Crystal size / mm	0.30×0.30×0.18	0.27×0.24×0.23
  θ range for data collection / (°)	3.02～25.05	3.31～25.05
  Limiting indices	-15 ≤ h ≤ 16, -16 ≤ k ≤ 16, -23 ≤ l ≤ 23	-14 ≤ h ≤ 14, -16 ≤ k ≤ 16, -17 ≤ l ≤ 17
  Reflections collected, unique (Rint)	26 653, 12 332 (0.060 8)	14 229, 7 939 (0.027 6)
  Dc (g·cm-3)	1.398	1.521
  μ / mm-1	0.434	0.513
  Data, restraints, parameters	12 332, 114, 948	7 939, 1, 674
  Goodness-of-fit on F2	0.963	1.007
  R1, wR2 [I≥2σ(I)]	0.069 7, 0.152 7	0.043 9, 0.090 4
  R1, wR2 (all data)	0.127 3, 0.186 6	0.053 4, 0.096 6
  Largest diff. peak and hole / (e·nm-3)	400 and -381	1 089 and -635

  下载: 导出CSV

  Table 2.  Selected bond distances (nm) and bond angles (°) for

  1
  Mn(1)-O(1)	0.210 0(4)	Mn(1)-O(4)A	0.210 4(3)	Mn(1)-N(1)	0.227 4(4)
  Mn(1)-N(2)	0.239 7(4)	Mn(1)-N(3)	0.232 5(4)	Mn(1)-N(4)	0.226 7(4)
  Mn(2)-O(9)	0.212 5(3)	Mn(2)-O(10)B	0.215 4(3)	Mn(2)-N(5)	0.225 5(5)
  Mn(2)-N(6)	0.232 6(4)	Mn(2)-N(7)	0.226 3(4)	Mn(2)-N(8)	0.227 8(4)
  O(1)-Mn(1)-O(4)A	100.10(14)	O(1)-Mn(1)-N(4)	112.46(15)	0(4)A-Mn(1)-N(4)	91.69(12)
  O(1)-Mn(1)-N(1)	87.92(18)	0(4)A-Mn(1)-N(1)	103.85(13)	N(4)-Mn(1)-N(1)	151.98(16)
  O(1)-Mn(1)-N(3)	88.92(14)	0(4)A-Mn(1)-N(3)	163.88(13)	N(4)-Mn(1)-N(3)	72.44(14)
  N(1)-Mn(1)-N(3)	89.70(14)	O(1)-Mn(1)-N(2)	158.33(17)	0(4)A-Mn(1)-N(2)	90.35(13)
  N(4)-Mn(1)-N(2)	85.89(15)	N(1)-Mn(1)-N(2)	71.08(17)	N(3)-Mn(1)-N(2)	85.77(14)
  0(9)-Mn(2)-O(10)B	98.64(12)	0(9)-Mn(2)-N(5)	91.39(14)	0(10)B-Mn(2)-N(5)	90.51(16)
  O(9)-Mn(2)-N(7)	172.46(13)	O(10)B-Mn(2)-N(7)	87.43(13)	N(5)-Mn(2)-N(7)	93.05(15)
  O(9)-Mn(2)-N(8)	100.79(14)	O(10)B-Mn(2)-N(8)	103.58(13)	N(5)-Mn(2)-N(8)	159.62(15)
  N(7)-Mn(2)-N(8)	73.28(15)	O(9)-Mn(2)-N(6)	90.56(14)	O(10)B-Mn(2)-N(6)	161.55(17)
  N(5)-Mn(2)-N(6)	73.2(2)	N(7)-Mn(2)-N(6)	84.89(14)	N(8)-Mn(2)-N(6)	90.24(18)
  2
  Ni(1)-O(1)	0.208 3(2)	Ni(1)-O(2)A	0.205 9(2)	Ni(1)-N(1)	0.208 O(2)
  Ni(1)-N(2)	0.210 4(2)	Ni(1)-N(3)	0.206 8(2)	Ni(1)-N(4)	0.208 6(2)
  O(2)A-Ni(1)-N(3)	97.32(8)	O(2)A-Ni(1)-N(1)	86.43(8)	N(3)-Ni(1)-N(1)	172.03(9)
  O(2)A-Ni(1)-O(1)	88.93(7)	N(3)-Ni(1)-O(1)	97.6O(8)	N(1)-Ni(1)-O(1)	89.47(8)
  O(2)A-Ni(1)-N(4)	175.73(8)	N(3)-Ni(1)-N(4)	80.07(8)	N(1)-Ni(1)-N(4)	95.75(8)
  O(1)-Ni(1)-N(4)	94.76(8)	O(2)A-Ni(1)-N(2)	86.26(8)	N(3)-Ni(1)-N(2)	93.22(8)
  N(1)-Ni(1)-N(2)	79.97(9)	O(1)-Ni(1)-N(2)	168.64(8)	N(4)-Ni(1)-N(2)	90.5O(8)
  Symmetry codes: A: -x, -y+1, -z+1; B: -x, -y+2, -z+2 for 1; A: -x+1, -y+1, -z for 2.

  下载: 导出CSV

  Table 3.  Hydrogen bond lengths (nm) and angles (°) of compound 1

  D-H…A	d(D-H)	d(H…A)	d(D…A)	∠DHA
  O(6)-H(6)…O(14)C	0.082	0.189	0.262 6	148.4
  O(8)-H(8)…O(12)D	0.082	0.170	0.251 0	171.4
  O(13)-H(13A)…O(14)	0.084	0.224	0.307 3	178.4
  O(13)-H(13B)…O(3)	0.085	0.192	0.276 9	178.6
  O(14)-H(14A)…O(2)A	0.085	0.202	0.286 9	178.7
  O(15)-H(15A)…O(3)	0.085	0.216	0.283 9	136.6
  O(16)-H(16B)…O(7)E	0.085	0.216	0.300 7	179.7
  O(17)-H(17A)…O(13)	0.098	0.213	0.298 5	144.8
  Symmetry codes: A: -x, -y+1, -z+1; B: -x, -y+2, -z+2; C: x-1, y, z; D: x+1, y, z; E: x, y-1, z.

  下载: 导出CSV

  Table 4.  Hydrogen bond lengths (nm) and angles (°) of compound 2

  D-H…A	d(D-H)	d(H…A)	d(D…A)	∠DHA
  O(3)-H⑴…O(6)A	0.082	0.179	0.260 6	172.2
  O(7)-H(2)…O(5)B	0.082	0.177	0.258 3	170.4
  O(10)-H(4)…O(12)C	0.082	0.180	0.261 8	172.8
  O(11)-H(5)…O(9)A	0.084	0.177	0.261 3	175.0
  O(13)-H(1W)…O(6)B	0.092	0.198	0.290 4	174.0
  O(13)-H(2W)…O(14)E	0.073	0.212	0.283 0	166.0
  O(14)-H(3W)…O(13)D	0.085	0.197	0.282 2	179.7
  O(14)-H(4W)…O(8)B	0.085	0.213	0.298 3	179.7
  Symmetry codes: A: x, y-1, z; B: -x+1, -y+1, -z+1; C: x, y+1, z; D: -x+2, -y+1, -z+1; E: x, y-1, z+1.

  下载: 导出CSV
•