English

• 1. INTRODUCTION

  Recently, there has been great interest in coordination polymers not only steming from their potential applications in gas storage^[1], catalysis^[2], and fluorescence^{[3, 4]}, but also from their pleasing variety of frameworks^[5] and novel motifs^[6]. The crystal design and synthesis of multidimensional arrays and networks based on crystal engineering have made considerable progress^[7]. Chemists have raised a lot in manipulating intermolecular forces like hydrogen bonds and π∙∙∙π stacking interactions to construct supramolecular architectures with interesting structures and useful properties^[8-10]. In particular, the development of metalloligand-bridged bimetallic assemblies has been widely used to construct multidimensional organic-inorganic coordination polymers^[11-13].

  The metalloligand strategy is a very attractive and well established approach to design and synthesize intriguing heterobimetallic metallosupramolecular architectures^{[14, 15]}. Macrocyclic oxamide metalloligands have been widely used to prepare heterobimetallic complexes and the two oxygen atoms of the oxamido group are active in chelating metal ions^[16-18]. In previous works^{[12, 13, 19]}, we have shown that these metalloligands can coordinate with metals through the carboxylate oxygens and two oxygen atoms of the oxamido group. In this paper, we report the syntheses, structures, IR spectroscopy, thermogravimetric analysis and fluorescent properties {[Co(NiL)(H₂O)₃]·4H₂O}_n (1) and {[Cu(NiL)-(H₂O)₃]·4H₂O}_n (2), by using the macrocyclic oxamide metalloligand NiL as building blocks (Scheme 1).

  Scheme 1

  

  Scheme 1.  Macrocyclic oxamide metalloligand NiL

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  2. EXPERIMENTAL

  2.1 Materials and physical measurements

  All starting materials and solvents were purchased commercially and used without further purification. 1, 1΄-Oxalylbisisatin and its ring opening in NaOH solution were prepared by the literature method^[20]. NiL was prepared according to the literature method^[19]. Infrared spectra were recorded as KBr pellets on a BIO-RAD 3000 infrared spectrophotometer in the 4000~400 cm^–1 region. Elemental analyses of C, H and N were determined with a Perkin-Elmer 240 Elemental Analyzer. Thermogravimetric analyses (TGA) were carried out in nitrogen stream using a STA-409PC equipment at a heating rate of 10 ℃/min. Powder X-ray diffraction (PXRD) data were recorded on a Rigaku D/max 2500v/pc X-ray powder diffractometer (CuKα, 1.5418 Å). The solid-state luminescence spectra were detected on a Cary Eclipse fluorescence spectrophotometer at room temperature.

  2.2 Synthesis of {[Co(NiL)(H₂O)₃]·4H₂O}_n (1)

  The mixture of metalloligand Na₂L (0.0705 g, 0.1348 mmol), Co(NO₃)₂·6H₂O (0.0397 g, 0.1364 mmol), DMF (10 mL) and water (50 mL) was stirred to form a red solution. The filtrate of the solution was then stored at room temperature for 30 days, and red crystals suitable for X-ray single-crystal analysis were formed. Yield: 0.0468 g (ca. 42%, calculated on the amount of Co(NO₃)₂·6H₂O). Anal. Calcd. for C₂₁H₂₈CoN₄NiO₁₃: C, 38.10; H, 4.26; N, 8.46%. Found: C, 37.98; H, 4.29; N, 8.51%. IR (KBr): 3420(s), 1611(vs), 1485(w), 1444(m), 1397(s), 1346(m), 1258(m), 755(m).

  2.3 Synthesis of {[Cu(NiL)(H₂O)₃]·4H₂O}_n (2)

  The mixture of metalloligand Na₂L (0.0688 g, 0.1315 mmol), Cu(NO₃)₂·6H₂O (0.0393 g, 0.1329 mmol), DMF (10 mL) and water (50 mL) was stirred to form a red solution. The filtrate of the solution was then stored at room temperature for 30 days, forming red crystals suitable for X-ray single-crystal analysis. Yield: 0.0378 g (ca. 35%, calculated on the amount of Cu(NO₃)₂·6H₂O). Anal. Calcd. for C₂₁H₂₈CuN₄NiO₁₃: C, 37.83; H, 4.23; N, 8.40%. Found: C, 37.76; H, 4.26; N, 8.45%. IR (KBr): 3388(s), 1605(vs), 1487(w), 1444(m), 1398(s), 1342(m), 1262(m), 751(m).

  2.4 Crystal structure determination and refinements

  X-ray diffraction intensity data for complexes 1 and 2 were collected at 113(2) K with a Rigaku Saturn724 CCD area detector using graphite-monochromated MoKα radiation (λ = 0.71073 Å) with ω-φ scans. The structures were solved by direct methods using SHELXS-97 program^[21] and refined with SHELXL-97^[22] by full-matrix least-squares techniques on F². All hydrogen atoms were located geometrically and the non-hydrogen atoms were refined with anisotropic displacement parameters. Crystal data collection and refinement parameters are given in Table 1. Selected bond lengths and bond angles are listed in Tables 2 and 3, respectively.

  Table 1

  

  Table 1.  Crystal Data and Structure Refinements for Complexes 1 and 2

  DownLoad: CSV

  Complex	1	2
  Formula	C21H28CoN4NiO13	C21H28CuN4NiO13
  Fw	662.11	666.72
  Temperature/K	113(2)	113(2)
  Wave length/Å	0.71073	0.71073
  Crystal system	Orthorhombic	Orthorhombic
  Space group	Pbca	Pbca
  a/Å	14.156(4)	14.072(3)
  b/Å	15.385(5)	15.383(3)
  c/Å	24.687(7)	24.636(5)
  α/°	90.00	90.00
  β/°	90.00	90.00
  γ/°	90.00	90.00
  V/Å3	5377(3)	5333.0(19)
  Z	8	8
  Dc/Mg·m–3	1.636	1.661
  μ/mm-1	1.390	1.577
  F(000)	2728	2744
  Crystal size/mm	0.20×0.18×0.10	0.20×0.18×0.16
  Reflns. collected	38290	45133
  Unique (Rint)	4750 (0.1097)	6382 (0.0477)
  Data/restraints	4750 / 115	6382 / 119
  Parameters	418	429
  Goof on F2	1.035	1.101
  R (I > 2σ(I))	0.0695	0.0451
  wR (I > 2σ(I))	0.1792	0.1053

  Table 2

  

  Table 2.  Selected Bond Lengths (Å) and Bond Angles (°) for Complex 1

  DownLoad: CSV

  Bond	Dist.		Bond	Dist.
  Ni(1)–N(1)	1.890(3)		Ni(1)–N(2)	1.891(3)
  Ni(1)–N(3)	1.867(3)		Ni(1)–N(4)	1.871(3)
  Co(1)–O(1)	2.093(2)		Co(1)–O(6)a	2.065(2)
  Co(1)–O(2)	2.098(2)		N(1)–Ni(1)–N(4)	93.31(12)
  Angle	(°)		Angle	(°)
  N(1)–Ni(1)–N(2)	87.24(11)		N(3)–Ni(1)–N(4)	85.78(12)
  N(3)–Ni(1)–N(1)	178.39(12)		N(3)–Ni(1)–N(2)	93.62(12)
  N(4)–Ni(1)–N(2)	177.74(12)		O(1)–Co(1)–O(2)	78.38(9)
  O(1)–Co(1)–O(6)a	89.42(8)		Co(1)–O(1)–C(1)	114.4(2)
  O(2)–Co(1)–O(6)a	86.66(9)		Co(1)–O(2)–C(2)	114.4(2)
  Symmetry code A: –1/2+x, 1/2–y, 1–z

  Table 3

  

  Table 3.  Selected Bond Lengths (Å) and Bond Angles (°) for Complex 2

  DownLoad: CSV

  Bond	Dist.		Bond	Dist.
  Ni(1)–N(1)	1.8930(16)		Ni(1)–N(2)	1.8969(16)
  Ni(1)–N(3)	1.8661(17)		Ni(1)–N(4)	1.8664(17)
  Cu(1)–O(1)	2.1140(14)		Cu(1)–O(6)b	2.0278(14)
  Cu(1)–O(2)	2.0582(14)		N(1)–Ni(1)–N(4)	93.54(7)
  Angle	(°)		Angle	(°)
  N(1)–Ni(1)–N(2)	87.32(7)		N(3)–Ni(1)–N(4)	85.65(7)
  N(3)–Ni(1)–N(1)	178.34(7)		N(3)–Ni(1)–N(2)	93.44(7)
  N(4)–Ni(1)–N(2)	177.77(7)		O(1)–Cu(1)–O(2)	78.65(5)
  O(1)–Cu(1)–O(6)a	89.42(8)		Cu(1)–O(1)–C(1)	113.17(12)
  O(2)–Cu(1)–O(6)a	86.66(9)		Cu(1)–O(2)–C(2)	114.83(12)
  Symmetry code A: 1/2 + x, 1/2 – y, 1 – z

  3. RESULTS AND DISCUSSION

  3.1 Crystal structures of the coordination polymers

  X-ray single-crystal analyses showed that the NiL ligands in 1 and 2 are arranged in a ''head-to-tail'' mode to form very similar single stranded heterobimetallic zigzag coordination polymer chains (Fig. 1). Each NiL ligand chelates with a metal center by two oxygen atoms of the oxamido and links to another metal center by using an oxygen atom from the carboxylate group. The NiL ligands with such an unsymmetric exoditopic coordination mode are efficient to generate zigzag coordination polymer chains. The Ni(II) center of every NiL coordinated by four nitrogen atoms of metalloligand in 1 and 2 takes on distorted square planar coordination geometry with the [NiN₄] chromophore. The four nitrogen atoms N(1)~N(4) deviate from the corresponding [NiN₄] planes with no more than 0.007 Å for the two complexes and the Ni atom falls in the 0.028~0.029 Å range away from their mean plane.

  Figure 1

  

  Figure 1.  Molecular structures of complexes 1 (left) and 2 (right) with limited numbering scheme (The uncoordinated H₂O molecules and hydrogen atoms are omitted for clarity)

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  The metalloligand NiL with a rigid structure and the carboxylate groups of NiL ligand are freedom of wagging, which is powerful in maintaining their shapes for the formation of zigzag chains. The binding of the metalloligand NiL to Co(II) and Cu(II) to form heterobimetallic zigzag chains has not been reported before. The oxygen atoms of both oxamido and carboxylate groups are good at coordinating to metal ions, and the arrangements of donor atoms around a metal center also greatly influence the structures of the metalloligand assembly. Metal ions in 1 and 2 bridging the NiL ligands have distorted octahedral coordination geometry defined by six oxygen atoms, of which two are from the oxamido carbonyls of a NiL ligand, one (O6) from a carboxylate group of another NiL ligand, and the other three from water molecules. The Co–O bond lengths range from 2.040(2) to 2.098(2) Å and the Cu–O bond lengths fall in the 2.016(1)~2.114(1) Å region.

  Complexes 1 and 2 exhibit novel zigzag one-dimensional chain structures along the c axis. Each NiL ligand of a zigzag chain overlaps with a NiL ligand of a neighboring chain, and the distances of the planes composed by the four nitrogen atoms of the two NiL ligands are 3.75 Å of 1 and 3.74 Å of 2 (Fig. 2). The dihedral angle between the two planes for 1 is 0.000(97)° and that for 2 is 0.000(59)°, which are arranged in a nearly parallel fashion and involved in intermolecular π∙∙∙π interactions. In complex 1, the Ni(II)∙∙∙Ni(II) and Co(II)∙∙∙Co(II) distances within the neighboring zigzag chains are 4.538(1) and 7.730(3) Å, but 4.554(1) and 7.725(2) Å correspondingly in 2.

  Figure 2

  

  Figure 2.  View of the 1D zigzag chains for complex 1. Hydrogen atoms and lattice water molecules are omitted for clarity

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  In addition, {[Co(NiL)(H₂O)₃]·4H₂O}_n (1) and {[Cu(NiL)(H₂O)₃]·4H₂O}_n (2) units are assembled through π∙∙∙π stacking of the parallel phenyl rings of NiL groups (for 1 d_cent–cent = 4.032(1) Å, dihedral angle = 7.5°; and for 2 d_cent–cent = 4.049(1) Å, dihedral angle = 7.8°)^[23]. These π∙∙∙π interactions dispose the zigzag one-dimensional chains to form 2D layers (Fig. 3).

  Figure 3

  

  Figure 3.  View of the 2D layers through π∙∙∙π interactions for complex 1

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  Rich intermolecular O–H∙∙∙O hydrogen bonds are observed in complexes 1 and 2. The corresponding parameters of the hydrogen bonds are given in Tables 4 and 5, respectively. The hetero-bimetallic zigzag chains and water molecules are alternately linked by strong hydrogen bonds (O–H∙∙∙O) that contribute to the stabilization of the final 3D frameworks. Furthermore, as depicted in Fig. 4, the onedimensional zigzag chains are interconnected into close -packed 3D networks through π∙∙∙π interactions and hydrogen bonds.

  Table 4

  

  Table 4.  Hydrogen Bond Lengths (Å) and Bond Angles (°) for Complex 1

  DownLoad: CSV

  D–H···A	d(D–H)	d(H···A)	d(D···A)	DHA
  O(9)–H(9B)···O(10)	0.849(8)	1.834(8)	2.659(4)	163.5(16)
  O(10)–H(10B)···O(13)	0.856(8)	1.884(13)	2.710(4)	162(3)
  O(7)–H(7B)···O(4) (–x+1, –y+1, –z+1)	0.85	1.86	2.688(3)	162.4
  O(8)–H(8A)···O(3) (–x+1/2, –y+1, z+1/2)	0.860(7)	1.913(9)	2.743(3)	162(3)
  O(8)–H(8B)···O(5) (x–1/2, –y+1/2, –z+1)	0.856(8)	1.861(11)	2.698(3)	165.3(17)
  O(7)–H(7A)···O(11) (x–1/2, y, –z+3/2)	0.85	1.92	2.751(3)	164.2
  O(9)–H(9A)···O(12) (x–1/2, –y+1/2, –z+1)	0.847(8)	1.938(8)	2.781(4)	173.8(16)
  O(11)–H(11A)···O(3) (–x+1, –y+1, –z+1)	0.855(7)	1.890(7)	2.713(3)	161(2)
  O(12)–H(12A)···O(8) (–x+1, –y+1, –z+1)	0.85	2.00	2.824(3)	162.1
  O(11)–H(11B)···O(5) (x+1/2, –y+1/2, –z+1)	0.852(9)	1.944(8)	2.757(3)	159.4(14)
  O(10)–H(10A)···O(4) (–x+1/2, –y+1, z+1/2)	0.854(9)	1.948(10)	2.790(4)	168(2)
  O(13)–H(13A)···O(12) (x–1, –y+1/2, z+1/2)	0.85	2.02	2.855(4)	167.5
  O(13)–H(13B)···O(11) (–x+1, y–1/2, –z+3/2)	0.85	2.07	2.837(4)	150.2

  Table 5

  

  Table 5.  Hydrogen Bond Lengths (Å) and Bond Angles (°) for Complex 2

  DownLoad: CSV

  D–H···A	d(D–H)	d(H···A)	d(D···A)	DHA
  O(9)–H(9A)···O(10)	0.853(7)	1.789(7)	2.642(2)	178.0(16)
  O(9)–H(9B)···O(11)	0.850(8)	1.937(8)	2.785(2)	175.4(17)
  O(11)–H(11B)···O(1)	0.844(7)	2.532(13)	3.050(2)	120.6(12)
  O(7)–H(7A)···O(5) (x+1/2, –y+1/2, –z+1)	0.849(7)	1.879(9)	2.6894(19)	159.0(12)
  O(7)–H(7B)···O(4) (–x+1/2, –y, z–1/2)	0.851(7)	1.895(7)	2.7453(19)	177.7(19)
  O(8)–H(8A)···O(3) (–x, –y, –z+1)	0.855(7)	1.847(7)	2.678(2)	163.3(12)
  O(8)–H(8B)···O(12) (–x+1/2, –y+1, z–1/2)	0.848(6)	1.914(9)	2.741(2)	165(2)
  O(10)–H(10A)···O(13) (x+1/2, –y+1/2, –z+1)	0.86	1.86	2.717(2)	174.9
  O(10)–H(10B)···O(3) (–x+1/2, –y, z–1/2)	0.86	1.93	2.788(2)	170.1
  O(11)–H(11A)···O(7) (–x+1/2, y+1/2, z)	0.845(7)	1.987(8)	2.805(2)	162.8(18)
  O(12)–H(12A)···O(4) (x, y+1, z)	0.851(7)	1.887(7)	2.713(2)	163.3(19)
  O(12)–H(12B)···O(5) (–x+1/2, y+1/2, z)	0.853(8)	1.932(8)	2.748(2)	159.4(13)
  O(13)–H(13A)···O(11) (x, –y+1/2, z+1/2)	0.86	2.00	2.845(2)	168.7
  O(13)–H(13B)···O(12) (x–1/2, y–1, –z+3/2)	0.85	1.99	2.831(2)	172.9

  Figure 4

  

  Figure 4.  View of the 3D networks through π∙∙∙π interactions and hydrogen bonds for complex 1

  DownLoad: Full-Size Img PowerPoint

  The crystal structures of 1 and 2 are very similar, and they both exhibit close-packed one-dimensional zigzag chains, which make their crystal structures more stable and not prone to structural collapse, even if parts of free water molecules are released.

  3.2 Infrared spectra

  The IR spectra of compounds 1 and 2 were performed as KBr pellets in the range of 4000~400 cm^–1. The presence of water molecules is confirmed by the appearance of a broad band absorption at 3600~2700 cm^–1 in the IR spectrum. The ν_C=O (oxamido carbonyl) band groups of 1 and 2 have shifted to 1611 and 1605 cm^–1, respectively due to the coordination of oxamido carbonyls to th metal centres^[24]. The bands at 1397 cm^–1 of 1 and 1398 cm^–1 of 2 can be assigned to the absorption of ν_s (COO^–) groups. The IR spectrum exhibits bands at 1346 cm^–1 for 1 and 1342 cm^–1 for 2 assigned to the ν_C-N vibrations.

  3.3 Thermogravimetric analysis

  X-ray powder diffraction (XRD) measurements for 1 and 2 (Figs. 5 and 6) indicated that the peaks displayed in the measured patterns for each compound closely match those in the simulated patterns generated from single-crystal diffraction data, indicating single phases were formed.

  Figure 5

  

  Figure 5.  XRD patterns of 1 simulated from the X-ray single-crystal structure and as-synthesized samples

  DownLoad: Full-Size Img PowerPoint

  Figure 6

  

  Figure 6.  XRD patterns of 2 simulated from X-ray single-crystal structure and the as-synthesized samples

  DownLoad: Full-Size Img PowerPoint

  In order to examine the thermal stability of the two compounds, thermogravimetric analysis (TGA) on polycrystalline samples of 1 and 2 was carried out in N₂ atmospheres, and the very similar TG curves are shown in Fig. 7. 1 and 2 started to slowly lose weight at the beginning of heating (30 ℃). The calculated weight percentage of all lattice water molecules in 1 is 10.88% and in 2 is 10.81%, so the first stage of weight loss is mainly related to the release of them. An obvious turn exists in the TGA curve of 1 at ca. 370 ℃ and the weight loss percentage is 26.13% which corresponds to the complete removal of lattice and coordination water molecules as well as the decomposition of part COO^– groups. The calculated weight loss percentage consistent with all the lattice and coordination water molecules in 2 is 18.91%. The TGA curve at ca. 360 ℃ shows distinct turn (the corresponding weight loss percentage is 28.63%), which can be attributed to the full release of all lattice and coordination water and the decomposition of part COO^– groups. Heating the samples to higher temperature led to the decomposition of other components.

  Figure 7

  

  Figure 7.  TGA plots of compounds 1 and 2

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  3.4 Fluorescent properties

  The fluorescent properties of complexes 1 and 2 as well as the free ligand were investigated at room temperature in the solid state. Excitation of the samples at 320 nm leads to the generation of broad fluorescence emissions in the range of 330~880 nm (Fig. 8). The free metalloligand with rigid planar construction and big unlocalized π bond shows a strong fluorescence emission band maximized at 388 nm, which can be ascribed to the π*→π transition^[25]. The two heterobimetallic zigzag coordination polymers 1 and 2 show similar maximum fluorescent emission bands, 378 nm for 1 (λ_ex = 320 nm) and 380 nm for 2 (λ_ex = 320 nm). The emissions of 1 and 2 are neither metal-to-ligand charge transfer (MLCT) nor ligand-to-metal transfer (LMCT) in nature, which are tentatively attributed to the intraligand transition (π*→π) of metalloligand^{[26, 27]}. Compared with the emission of the free metalloligand L, blue-shifts of 10 and 8 nm have been observed separately in complexes 1 and 2, which may be due to the structure change for the complexes compared with the ligand. In addition, weaker shoulder peaks of the emission spectra around 730 nm can probably be assigned to the intraligand transition because a similar peak also appears for the free metalloligand L. Furthermore, the emission intensity of complexes 1 and 2 is obviously weaker than that of the free metalloligand, which is probably related to their complicated structures and the decay effect of high-energy O-H oscillators from the lattice and coordinated water molecules^[28]. The Co(II) and Cu(II) ions of 1 and 2 are well known to quench excited states, which led to fluorescence quenching, and strong decrease in the emission intensity^[29-31].

  Figure 8

  

  Figure 8.  The solid-state emission spectra for the free ligand Na₂L and compounds CuL and CoL

  DownLoad: Full-Size Img PowerPoint

  4. CONCLUSION

  In summary, two new interesting supramolecular networks constructed by packing the heterobimetallic zigzag polymer chains, {[Co(NiL)(H₂O)₃]·4H₂O}_n (1) and {[Cu(NiL)-(H₂O)₃]·4H₂O}_n (2), have been synthesized and characterized. In both 1 and 2, hydrogen bonds and π∙∙∙π stacking interactions play an important role in forming the 3D supramolecular networks. The thermal stability of the two compounds is very similar due to their similar crystal structures. The successful assembly of the two new heterobimetallic zigzag coordination polymer chains not only provides intriguing examples of inorganic-organic frameworks but also demonstrates that the contemporary use of metalloligands opens a promising route for the construction of novel supramolecular networks, a goal we are actively pursuing.

  
  
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  Scheme 1  Macrocyclic oxamide metalloligand NiL

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  Figure 1  Molecular structures of complexes 1 (left) and 2 (right) with limited numbering scheme (The uncoordinated H₂O molecules and hydrogen atoms are omitted for clarity)

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  Figure 2  View of the 1D zigzag chains for complex 1. Hydrogen atoms and lattice water molecules are omitted for clarity

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  Figure 3  View of the 2D layers through π∙∙∙π interactions for complex 1

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  Figure 4  View of the 3D networks through π∙∙∙π interactions and hydrogen bonds for complex 1

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  Figure 5  XRD patterns of 1 simulated from the X-ray single-crystal structure and as-synthesized samples

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  Figure 6  XRD patterns of 2 simulated from X-ray single-crystal structure and the as-synthesized samples

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  Figure 7  TGA plots of compounds 1 and 2

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  Figure 8  The solid-state emission spectra for the free ligand Na₂L and compounds CuL and CoL

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  Table 1.  Crystal Data and Structure Refinements for Complexes 1 and 2

  Complex	1	2
  Formula	C21H28CoN4NiO13	C21H28CuN4NiO13
  Fw	662.11	666.72
  Temperature/K	113(2)	113(2)
  Wave length/Å	0.71073	0.71073
  Crystal system	Orthorhombic	Orthorhombic
  Space group	Pbca	Pbca
  a/Å	14.156(4)	14.072(3)
  b/Å	15.385(5)	15.383(3)
  c/Å	24.687(7)	24.636(5)
  α/°	90.00	90.00
  β/°	90.00	90.00
  γ/°	90.00	90.00
  V/Å3	5377(3)	5333.0(19)
  Z	8	8
  Dc/Mg·m–3	1.636	1.661
  μ/mm-1	1.390	1.577
  F(000)	2728	2744
  Crystal size/mm	0.20×0.18×0.10	0.20×0.18×0.16
  Reflns. collected	38290	45133
  Unique (Rint)	4750 (0.1097)	6382 (0.0477)
  Data/restraints	4750 / 115	6382 / 119
  Parameters	418	429
  Goof on F2	1.035	1.101
  R (I > 2σ(I))	0.0695	0.0451
  wR (I > 2σ(I))	0.1792	0.1053

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  Table 2.  Selected Bond Lengths (Å) and Bond Angles (°) for Complex 1

  Bond	Dist.		Bond	Dist.
  Ni(1)–N(1)	1.890(3)		Ni(1)–N(2)	1.891(3)
  Ni(1)–N(3)	1.867(3)		Ni(1)–N(4)	1.871(3)
  Co(1)–O(1)	2.093(2)		Co(1)–O(6)a	2.065(2)
  Co(1)–O(2)	2.098(2)		N(1)–Ni(1)–N(4)	93.31(12)
  Angle	(°)		Angle	(°)
  N(1)–Ni(1)–N(2)	87.24(11)		N(3)–Ni(1)–N(4)	85.78(12)
  N(3)–Ni(1)–N(1)	178.39(12)		N(3)–Ni(1)–N(2)	93.62(12)
  N(4)–Ni(1)–N(2)	177.74(12)		O(1)–Co(1)–O(2)	78.38(9)
  O(1)–Co(1)–O(6)a	89.42(8)		Co(1)–O(1)–C(1)	114.4(2)
  O(2)–Co(1)–O(6)a	86.66(9)		Co(1)–O(2)–C(2)	114.4(2)
  Symmetry code A: –1/2+x, 1/2–y, 1–z

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  Table 3.  Selected Bond Lengths (Å) and Bond Angles (°) for Complex 2

  Bond	Dist.		Bond	Dist.
  Ni(1)–N(1)	1.8930(16)		Ni(1)–N(2)	1.8969(16)
  Ni(1)–N(3)	1.8661(17)		Ni(1)–N(4)	1.8664(17)
  Cu(1)–O(1)	2.1140(14)		Cu(1)–O(6)b	2.0278(14)
  Cu(1)–O(2)	2.0582(14)		N(1)–Ni(1)–N(4)	93.54(7)
  Angle	(°)		Angle	(°)
  N(1)–Ni(1)–N(2)	87.32(7)		N(3)–Ni(1)–N(4)	85.65(7)
  N(3)–Ni(1)–N(1)	178.34(7)		N(3)–Ni(1)–N(2)	93.44(7)
  N(4)–Ni(1)–N(2)	177.77(7)		O(1)–Cu(1)–O(2)	78.65(5)
  O(1)–Cu(1)–O(6)a	89.42(8)		Cu(1)–O(1)–C(1)	113.17(12)
  O(2)–Cu(1)–O(6)a	86.66(9)		Cu(1)–O(2)–C(2)	114.83(12)
  Symmetry code A: 1/2 + x, 1/2 – y, 1 – z

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  Table 4.  Hydrogen Bond Lengths (Å) and Bond Angles (°) for Complex 1

  D–H···A	d(D–H)	d(H···A)	d(D···A)	DHA
  O(9)–H(9B)···O(10)	0.849(8)	1.834(8)	2.659(4)	163.5(16)
  O(10)–H(10B)···O(13)	0.856(8)	1.884(13)	2.710(4)	162(3)
  O(7)–H(7B)···O(4) (–x+1, –y+1, –z+1)	0.85	1.86	2.688(3)	162.4
  O(8)–H(8A)···O(3) (–x+1/2, –y+1, z+1/2)	0.860(7)	1.913(9)	2.743(3)	162(3)
  O(8)–H(8B)···O(5) (x–1/2, –y+1/2, –z+1)	0.856(8)	1.861(11)	2.698(3)	165.3(17)
  O(7)–H(7A)···O(11) (x–1/2, y, –z+3/2)	0.85	1.92	2.751(3)	164.2
  O(9)–H(9A)···O(12) (x–1/2, –y+1/2, –z+1)	0.847(8)	1.938(8)	2.781(4)	173.8(16)
  O(11)–H(11A)···O(3) (–x+1, –y+1, –z+1)	0.855(7)	1.890(7)	2.713(3)	161(2)
  O(12)–H(12A)···O(8) (–x+1, –y+1, –z+1)	0.85	2.00	2.824(3)	162.1
  O(11)–H(11B)···O(5) (x+1/2, –y+1/2, –z+1)	0.852(9)	1.944(8)	2.757(3)	159.4(14)
  O(10)–H(10A)···O(4) (–x+1/2, –y+1, z+1/2)	0.854(9)	1.948(10)	2.790(4)	168(2)
  O(13)–H(13A)···O(12) (x–1, –y+1/2, z+1/2)	0.85	2.02	2.855(4)	167.5
  O(13)–H(13B)···O(11) (–x+1, y–1/2, –z+3/2)	0.85	2.07	2.837(4)	150.2

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  Table 5.  Hydrogen Bond Lengths (Å) and Bond Angles (°) for Complex 2

  D–H···A	d(D–H)	d(H···A)	d(D···A)	DHA
  O(9)–H(9A)···O(10)	0.853(7)	1.789(7)	2.642(2)	178.0(16)
  O(9)–H(9B)···O(11)	0.850(8)	1.937(8)	2.785(2)	175.4(17)
  O(11)–H(11B)···O(1)	0.844(7)	2.532(13)	3.050(2)	120.6(12)
  O(7)–H(7A)···O(5) (x+1/2, –y+1/2, –z+1)	0.849(7)	1.879(9)	2.6894(19)	159.0(12)
  O(7)–H(7B)···O(4) (–x+1/2, –y, z–1/2)	0.851(7)	1.895(7)	2.7453(19)	177.7(19)
  O(8)–H(8A)···O(3) (–x, –y, –z+1)	0.855(7)	1.847(7)	2.678(2)	163.3(12)
  O(8)–H(8B)···O(12) (–x+1/2, –y+1, z–1/2)	0.848(6)	1.914(9)	2.741(2)	165(2)
  O(10)–H(10A)···O(13) (x+1/2, –y+1/2, –z+1)	0.86	1.86	2.717(2)	174.9
  O(10)–H(10B)···O(3) (–x+1/2, –y, z–1/2)	0.86	1.93	2.788(2)	170.1
  O(11)–H(11A)···O(7) (–x+1/2, y+1/2, z)	0.845(7)	1.987(8)	2.805(2)	162.8(18)
  O(12)–H(12A)···O(4) (x, y+1, z)	0.851(7)	1.887(7)	2.713(2)	163.3(19)
  O(12)–H(12B)···O(5) (–x+1/2, y+1/2, z)	0.853(8)	1.932(8)	2.748(2)	159.4(13)
  O(13)–H(13A)···O(11) (x, –y+1/2, z+1/2)	0.86	2.00	2.845(2)	168.7
  O(13)–H(13B)···O(12) (x–1/2, y–1, –z+3/2)	0.85	1.99	2.831(2)	172.9

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