English

• 0.   Introduction

  Coordination polymers are usually obtained from multi-dentate organic ligands as building templates or assembled from connecting rods with metal ions as nodes^[1-2]. Among them, multi-dentate nitrogen-containing ligands, multi-dentate carboxylic acid ligands, and multi-dentate pyridine carboxylic acid ligands are the preferred ligands for the self-assembly of organic ligands^[3]. The complexes have potential applications in the fields of catalysis, ion recognition and antioxidation, electrochemistry, etc., and are one of the research hot spots in organometallic chemistry and coordination chemistry^[4-7]. The synthesis of coordination polymers using ligands containing carboxyl groups is more common. In addition to structural stability, due to the multiple coordination modes and bridging modes of carboxyl-containing ligands, the complexes are easy to obtain topological diversity and excellent properties. Ligands containing nitrogen or oxygen groups can be re-introduced during the construction of the complexes to increase the active sites, form more coordination modes, diversify the pore channels and improve their luminescence performance^[8-10].

  Among them, terephthalic acid-like ligands are one of the important ligands for the preparation of functional MOFs materials, because having bifunctional groups in the para-position provides the possibility of forming polymer chains of mono-and heterometallic two-or three-dimensional coordination compounds, which can be used as one of the ligands for the synthesis of bidentate, tridentate or tetradentate chelate complexes based on the characteristics of terephthalate ion structure. The presence of empty d orbitals in transition metals allows the use of hybrid orbitals to accept electrons, resulting in stable structures of 16 or 18 electrons, and thus are widely used for the preparation of complexes^[11-14].

  Our group chose 2,5-dibromoterephthalic acid (H₂L₁) as the primary ligand and 2,2'-bipyridine (L₂) and 1,10-phenanthroline (L₃) as the secondary ligands and obtained complexes [Mn₂(L₁)₂(L ₂)₂(H₂O)₂]_n (1) and [Co₂(L₁)₂(L₃)₂(H₂O)₂]_n (2). The structures were characterized by single-crystal X-ray diffraction and IR spectroscopy, and their thermal stability and fluorescence properties were also investigated.

  1.   Experimental

  1.1   Instruments and reagents

  H₂L₁ (Purity: 97%) was purchased from Shanghai Maclean Reagent Company; L₂ (Purity: 99%), L₃ (Purity: 99%), N, N-dimethylformamide (DMF, AR), manganese sulfate monohydrate (AR) and cobalt nitrate hexahydrate (AR) were purchased from Aladdin Reagent (Shanghai) Company.

  An Agilent Technologies G8910A single-crystal diffractometer was used to determine the crystal structure. A Perkin-Elmer 240Q elemental analyzer was used to determine the elemental contents (C, N, H). A Shimadzu FTIR-8400 FTIR spectrometer (with KBr compression) was used to measure the IR spectra of the complexes. A UV-5500PC double-beam UV-Vis spectrophotometer was used to determine the UV-Vis spectra of the complexes. An EDXRF-type fluorescence spectrometer was used to determine the fluorescence spectra of the complexes. An SDT-Q600 type synchronous TG/DTG analyzer was used for thermogravimetric analysis (TGA).

  1.2   Synthesis of the complexes

  DMF (6 mL), H₂O (4 mL), 0.2 mmol (0.064 8 g) of H₂L₁, 0.2 mmol (0.031 2 g) of L₂, and 0.2 mmol (0.057 5 g) of manganese sulphate monohydrate were placed in a beaker, stirred magnetically for 30 min and then placed in a reaction kettle. The reaction was carried out in an oven at 90 ℃ for 3 d, then cooled down to 50 ℃ at a rate of 10 ℃·h^-1 for 6 h and then reduced to room temperature. Massive yellow crystals of complex 1 (0.014 7 g) were obtained with a yield of 43.7% (based on Mn). Elemental analysis Calcd. for C₁₈H₁₂Br₂MnN₂O₅ (%): C, 39.20; N, 5.08; H, 2.18. Found(%): C, 39.52; N, 4.95; H, 2.11.

  Complex 2 was synthesized in a similar way to that of complex 1, using cobalt nitrate hexahydrate (0.058 2 g, 0.2 mmol) reacted with H₂L₁ (0.064 8 g, 0.2 mmol) and L₃ (0.036 0 g, 0.2 mmol). The reaction gave 0.029 7 g of red massive crystals in 51.2% yield (based on Co). Elemental analysis Calcd. for C₂₀H₁₂Br₂CoN₂O₅ (%): C, 41.45; N, 4.84; H, 2.07. Found(%): C, 41.08; N, 4.75; H, 2.01.

  1.3   Crystal structure determination

  Crystals with the sizes of 0.18 mm×0.16 mm×0.15 mm (1) and 0.19 mm×0.17 mm×0.15 mm (2) were selected and diffraction point data were collected using an Agilent Technologies G8910A single-crystal X-ray diffractometer with Mo Kα radiation (λ=0.071 073 nm) at a temperature of 293(2) K, using φ-ω scan^[15]. The raw data were reduced using the CryAlisPro program and all data were subjected to Lp factor correction and empirical absorption correction. The coarse structure was solved using the direct method in SHLEXS-97, and then the full matrix least-squares refinement of the nonhydrogen atomic coordinates and their anisotropic temperature factors was performed using the SHLEXL-97 program. All hydrogen atom coordinates were obtained using theoretical hydrogenation. The relevant crystallographic data are listed in Table 1 and the main bond lengths and bond angles are listed in Table 2.

  Table 1

  

  Table 1.  Crystallographic data for complexes 1 and 2

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  Parameter	1	2
  Empirical formula	C18H12Br2MnN2O5	C20H12Br2CoN2O5
  Formula weight	551.04	579.07
  Crystal system	Triclinic	Triclinic
  Space group	P1	P1
  a/nm	0.963 09(4)	0.958 91(3)
  b/nm	1.054 16(3)	1.064 44(4)
  c/nm	1.066 69(5)	1.076 36(3)
  α/(°)	109.841(4)	111.686(3)
  β/(°)	109.098(4)	92.367(3)
  γ/(°)	90.811(3)	108.351(3)
  V/nm3	0.953 01(7)	0.953 36(6)
  F(000)	538	566
  Z	2	2
  Dc/(g·cm-3)	1.920	2.017
  μ/mm-1	10.85	5.13
  θ range/(°)	4.5-77.3	2.1-29.3
  Reflection measured, independent	10 795, 4 052	9 861, 4 161
  Observed reflection [I≥2σ(I)]	3 670	3 220
  Rint	0.028	0.027
  R1 [I≥2σ(I)]	0.033	0.033
  wR2 (all data)	0.087	0.074
  GOF	1.04	1.05

  Table 2

  

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

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  1
  Mn1—O1	0.221 89(19)	Mn1—O1ⅰ	0.221 01(17)	Mn1—O3	0.211 7(2)
  Mn1—O5	0.220 9(2)	Mn1—N1	0.224 7(2)	Mn1—N2	0.223 8(2)
  O1—Mn1ⅰ	0.221 01(17)
  O1—Mn1—O1ⅰ	77.28(7)	N1—Mn1—O1ⅰ	97.79(8)	O1—Mn1—N1	95.38(8)
  O1—Mn1—N2	100.18(7)	N2—Mn1—O1ⅰ	170.69(8)	O3—Mn1—O1	90.37(8)
  O3—Mn1—O1ⅰ	93.92(8)	O3—Mn1—O5	91.21(10)	O3—Mn1—N1	167.85(10)
  O3—Mn1—N2	95.07(9)	O5—Mn1—O1	168.84(8)	O5—Mn1—O1ⅰ	91.58(8)
  O5—Mn1—N1	85.22(9)	O5—Mn1—N2	90.69(9)	N2—Mn1—N1	73.41(9)
  2
  Co1—N1	0.212 0(2)	Co1—N2	0.212 3(2)	Co1—O1	0.212 34(18)
  Co1—O1ⅲ	0.213 17(18)	Co1—O3	0.207 4(2)	Co1—O5	0.213 6(2)
  N1—Co1—N2	78.78(10)	N1—Co1—O1	97.66(8)	N1—Co1—O1ⅲ	98.12(8)
  N1—Co1—O5	83.22(9)	N2—Co1—O1ⅲ	175.06(8)	N2—Co1—O5	90.84(8)
  O1—Co1—N2	98.76(8)	O1—Co1—O1ⅲ	77.75(7)	O1—Co1—O5	170.36(8)
  O5—Co1—O1ⅲ	92.62(8)	O3—Co1—N1	169.90(9)	O3—Co1—N2	93.38(9)
  O3—Co1—O1	89.77(8)	O3—Co1—O1ⅲ	90.12(8)	O3—Co1—O5	90.61(9)
  C1—N1—C12	118.0(3)	C1—N1—Co1	128.7(2)	C12—N1—Co1	112.7(2)
  C10—N2—C11	117.7(3)	C10—N2—Co1	129.0(2)	C11—N2—Co1	113.09(19)
  C13—O1—Co1	132.86(18)	C13—O1—Co1ⅲ	124.55(17)	Co1—O1—Co1ⅲ	102.26(7)
  C17—O3—Co1	130.4(2)	Co1—O5—H11	109.8	Co1—O5—H12	110.2
  Symmetry codes: ⅰ-x, -y+1, -z+1; ⅱ -x+1, -y+1, -z+1; ⅲ -x, -y+2, -z+2 for 1; ⅰ -x+1, -y+1, -z+1; ⅱ -x, -y+2, -z+2; ⅲ -x, -y+1, -z+1 for 2.

  2.   Results and discussion

  2.1   Crystal structural analysis

  2.1.1   Crystal structure of complex 1

  As shown in Fig. 1a, each asymmetric unit of complex 1 consists of two Mn²⁺ ions, two L₁^2- ions, two L₂ molecules, and two coordinated water molecules. In the coordination environment of Mn1, O5 is an oxygen atom from the coordinated water molecule, O1 and O1^ⅰ are both oxygen atoms from the carboxyl group on L₁^2-, and N1 and N2 are nitrogen atoms from L₂, where the sum of the bond angles formed by O1, O1^ⅰ, O5, and N2 with the central Mn1 ion is 359.74°, which is close to the ideal angle (360°), indicating that these four coordination atoms are in the equatorial plane of the tetragonal bipyramidal cone and have good coplanarity. As shown in Fig. 1b, the carboxyl oxygen atom O3 on L₁^2- and N1 on L₂ are located in axial positions with axial bond angle O3—Mn1—N1 (167.85(10)°), forming a distorted [MnO₄N₂] tetragonal bipyramidal geometry. The coordination environment of Mn1^ⅰ is the same as that of Mn1, Mn—O (0.220 9(2)-0.221 89(19) nm), Mn—N (0.223 8(2)-0.224 7(2) nm) are in the normal range of bond lengths, the bond angles of O—Mn—O are in a range of 77.28(7)°-168.84(8)°, the bond angles of N—Mn—O are in a range of 85.22(9)°-170.69(8)°, and the bond angle of N—Mn—N is 73.41(9)°, all within the normal range^[16].

  Figure 1

  

  Figure 1.  Crystal structure of complex 1: (a) ellipsoid diagram with 30% probability level; (b) coordination polyhedron diagram; (c) 3D stacked diagram

  Symmetry codes: ^ⅰ -x, -y+1, -z+1; ^ⅱ-x+1, -y+1, -z+1; ^ⅲ -x, -y+2, -z+2

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  With Mn²⁺ as the metal node, L₁^2- and L₂ as the coordination linkages, the Mn1 and Mn1^ⅰ ions are connected by carboxyl oxygen atoms O1 and O1^ⅰ on L₁^2-, thus forming a fully symmetric bidentate chelate coordination structural unit. The intermolecular linkages through L₁^2- bridges form an infinitely extended 2D network-like structure. As shown in Fig. 1c, a 3D network-like structure is formed between adjacent layers through intermolecular hydrogen bonding and π-π stacking. The π-π stacking is between the Cg(1) ring (a ring consisting of N2^ⅰ -C5^ⅰ -C4^ⅰ -C3^ⅰ -C2^ⅰ -C1^ⅰ) and the Cg(2) ring (a ring consisting of C12^ⅰ-C14-C13-C12-C14^ⅰ-C13^ⅰ) between layer and layer molecules, where the distance from the Cg(1) ring to the center of the Cg(2) ring is 0.354 6 nm and the inter-ring dihedral angle is 5.511°. The pore size of complex 1 was calculated by the tools module of Diamond software as 0.83 nm × 2.05 nm.

  2.1.2   Crystal structure of complex 2

  As shown in Fig. 2a, each asymmetric unit of complex 2 consists of two Co²⁺ ions, two L₁^2- ions, two L₃ molecules, and two coordinated water molecules. In the coordination environment of Co1, O5 comes from the water molecule, O3, O1 and O1^ⅰ are the carboxyl oxygen atoms on L₁^2-, and N1 and N2 come from L₃. As shown in Fig. 2b, the carboxyl oxygen atom O3 on L₁^2-and N1 on L₃ are located in the axial position with axial bond angle O3—Co1—N1 (169.90(9)°), forming a distorted [CoO₄N₂] tetragonal bipyramidal geometry. The coordination environment of Co1^ⅰ is the same as that of Co1, Co—O (0.207 4(2) to 0.213 6(2) nm), Co—N (0.212 0(2) to 0.212 3(2) nm) are in the normal range of bond lengths, the bond angles of O—Co—O are in a range of 77.75(7)°-170.36(8)°, the bond angles of N—Co—O are in a range of 83.22(9)°-175.06(8)°, and the bond angle of N—Co—N is 78.80(10)°, all within the normal range^[17].

  Figure 2

  

  Figure 2.  Crystal structure of complex 2: (a) ellipsoid diagram with 30% probability level; (b) coordination polyhedron diagram; (c) 3D stacked diagram

  Symmetry codes: ^ⅰ -x, -y+1; ^ⅱ-x+1, -y+1, -z+1; ^ⅲ -x, -y+2, -z+2

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  With Co²⁺ as the metal node, L₁^2- and L₃ as the coordination linkage, the Co1 and Co1^ⅰ ions are connected by carboxyl oxygen atoms O1 and O1^ⅰ on L₁^2-, thus forming the coordination structural unit of the bidentate chelate. The intermolecular linkages via L₁^2-bridges form an infinitely extended 2D network-like structure. As shown in Fig. 2c, the adjacent layers are stacked to form a 3D network-like structure through O—H⋯O intermolecular hydrogen bonding and π-π stacking. The π-π stacking is between the Cg(1) ring consisting of N2-C10-C9-C8-C7-C11 and the Cg(2) ring consisting of C14^ⅰ-C15^ⅰ-C16^ⅰ-C14-C15-C16 between layer and layer molecules. The distance from the Cg(1) ring to the center of the Cg(2) ring is 0.355 8 nm and the dihedral angle between the two rings is 11. 709°. The pore size of complex 2 was calculated by the tools module of Diamond software, giving 2.07 nm × 1.52 nm.

  2.2   IR spectroscopic analysis

  The IR spectra of ligands H₂L₁, L₂, L₃, and complexes 1 and 2 were measured in a range of 4 000-400 cm^-1 using a Shimadzu FTIR-8400 infrared spectrometer (Fig. 3). As shown in Fig. 3a, the O—H stretching vibration peak for the carboxyl group of H₂L₁ appeared at 3 438 cm^-1, while this peak moved to 3 408 cm^-1 for complex 1. The C=O stretching vibration absorption peak for the carboxyl group of H₂L₁ appeared at 1 709 cm^-1, and this peak appeared at 1 609 cm^-1 for complex 1. The O—H bending vibration absorption peak of H₂L₁ at 900 cm^-1 did not move after the formation of complex 1. These indicate that the manganese ion is coordinated with the carboxyl group in H₂L₁. L₂ showed a C=N bending vibration absorption peak at 1 569 cm^-1, which moved to 1 609 cm^-1 for complex 1; the presence of the Mn—N absorption peak at 646 cm^-1 for complex 1 indicates that the nitrogen atom of L₂ is coordinated to the manganese ion^[18].

  Figure 3

  

  Figure 3.  IR spectra of complexes 1, 2, and the ligands

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  The IR spectrum of complex 2 is shown in Fig. 3b. The O—H stretching vibration peaks for the carboxyl group of H₂L₁ shown at 3 438 and 3 093 cm^-1 were shown again at both 3 403 and 3 051 cm^-1 for complex 2, which indicates that the carboxyl group in H₂L₁ is coordinated to the cobalt ion. The C=N stretching vibration peak for L₃ at 1 587 cm^-1 shifted to 1 608 cm^-1 after the formation of complex 2; the Co—N absorption peak shown at 534 cm^-1 for complex 2 indicates that the nitrogen atom of L₃ undergoes coordination with the cobalt ion^[19-20].

  2.3   UV-Vis and fluorescence spectra analysis

  The UV-Vis and fluorescence spectra of complexes 1 and 2 and ligands H₂L₁, L₂, and L₃ were measureds at room temperature. The samples were dissolved in DMF at a concentration of 10 μmol·L^-1 as a reference solution. The UV-Vis spectra of complexes 1 and 2 and ligands H₂L₁, L₂, and L₃ are shown in Fig. 4. Ligands H₂L₁, L₂, and L₃ and their complexes all showed an absorption peak around 270 nm, which can be attributed to the B-band where π-π* leap occurs on the intramolecular heterocyclic ring according to the molecular structure analysis.

  Figure 4

  

  Figure 4.  UV-Vis spectra of complexes 1, 2, and the ligands

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  The fluorescence emission spectra of complexes 1 and 2 and their ligands are shown in Fig. 5. The structures of ligands H₂L₁, L₂, L₃, and complexes 1 and 2 all contain heterocyclic conjugated π-bonds and are prone to fluorescence. The wavelengths of the maximum emission peaks of ligands H₂L₁, L₂, and L₃ were 348, 341, and 362 nm (λ_ex=305, 265, 289 nm, respectively), which are attributed to π-π* electron leap; while the wavelengths of the maximum emission peaks of complexes 1 and 2 were 355 and 365 nm (λ_ex=322, 319 nm, respectively), which were both red-shifted compared to the ligands. This may be because the energy level of the HOMO of the complex decreases and the energy level difference between the HOMO and the LUMO becomes larger after the coordination of the ligand with the metal ion; while the metallization effect elevates the HOMO energy level of the complex and the energy level difference between the HOMO and the LUMO decreases^[21]. The maximum emission wavelengths of complexes 1 and 2 were extremely similar, indicating that the fluorescence properties of both complexes are mainly based on the luminescence of L₁^2-itself in them. The main ligand H₂L₁ had a maximum excitation wavelength of 305 nm with a Stokes shift (Δλ) of 43 nm; the maximum excitation wavelength of complex 1 was 322 nm with a Δλ of 33 nm; the maximum excitation wavelength of complex 2 was 319 nm with a Δλ of 46 nm. Compared with the main ligand H₂L₁, the Stokes shifts of complexes 1 and 2 were smaller and the fluorescence efficiency was higher.

  Figure 5

  

  Figure 5.  Fluorescence emission spectra of complexes 1, 2, and the ligands

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  2.4   TGA of the complexes

  The TG and differential thermogravimetry (DTG) curves of complex 1 are shown in Fig. 6a. Complex 1 remained stable until 290 ℃, after which the skeleton began to collapse continuously as the temperature increased until about 440 ℃, when the skeleton collapsed completely, with a final residual rate of 12.91%. According to the common sense of coordination, the residue might be MnO, and the calculated value was 12.87%, which was consistent with the actual residual rate. As shown in Fig. 6b, complex 2 hardly decomposed before 130 ℃, and the first weight loss of 2. 05% occurred from 130 to 175 ℃, which is attributed to the decomposition of the coordinated water molecule and was consistent with the calculated value of 3.10%. After that, with the increase in temperature, the skeleton of the complex collapsed continuously, and at about 596 ℃, the skeleton collapsed completely. The final residual rate was 27.27%, and according to the common sense of coordination, the residue might be CoO (Calcd. 12.94%). The residual rate was greater than the calculated value, indicating that complex 2 was protected by N₂. The thermal decomposition yielded N-doped carbon material, which produced the carbon accumulation effect. In summary, both two complexes have certain thermal stability.

  Figure 6

  

  Figure 6.  TG and DTG curves of complexes 1 and 2

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  3.   Conclusions

  The organic 2,5-dibromoterephthalic acid was used as the primary ligand and 2,2'-bipyridine and 1,10-phenanthroline as the secondary ligands, and complexes [Mn₂(L₁)₂(L₂)₂(H₂O)₂]_n (1) and [Co₂(L₁)₂(L ₃)₂(H₂O)₂]_n (2) were synthesized with manganese sulfate monohydrate and cobalt nitrate hexahydrate, respectively, using a solvothermal method. The crystal structure analysis shows that complex 1 is an infinitely extended 2D network-like structure formed by L₁^2- and L₂ coordination linking Mn²⁺ ion, and each layer forms a 3D network-like structure under intermolecular hydrogen bonding and π-π stacking. Complex 2 is an infinitely extended 2D network-like structure formed by L₁^2- and L₃ coordination linking Co²⁺ ion, and the layers are stacked under intermolecular hydrogen bonding and π-π stacking to form a 3D network-like structure. Both 1 and 2 have good fluorescence properties and thermal stability.

  
  
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  Figure 1  Crystal structure of complex 1: (a) ellipsoid diagram with 30% probability level; (b) coordination polyhedron diagram; (c) 3D stacked diagram

  Symmetry codes: ^ⅰ -x, -y+1, -z+1; ^ⅱ-x+1, -y+1, -z+1; ^ⅲ -x, -y+2, -z+2

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  Figure 2  Crystal structure of complex 2: (a) ellipsoid diagram with 30% probability level; (b) coordination polyhedron diagram; (c) 3D stacked diagram

  Symmetry codes: ^ⅰ -x, -y+1; ^ⅱ-x+1, -y+1, -z+1; ^ⅲ -x, -y+2, -z+2

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  Figure 3  IR spectra of complexes 1, 2, and the ligands

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  Figure 4  UV-Vis spectra of complexes 1, 2, and the ligands

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  Figure 5  Fluorescence emission spectra of complexes 1, 2, and the ligands

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  Figure 6  TG and DTG curves of complexes 1 and 2

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  Table 1.  Crystallographic data for complexes 1 and 2

  Parameter	1	2
  Empirical formula	C18H12Br2MnN2O5	C20H12Br2CoN2O5
  Formula weight	551.04	579.07
  Crystal system	Triclinic	Triclinic
  Space group	P1	P1
  a/nm	0.963 09(4)	0.958 91(3)
  b/nm	1.054 16(3)	1.064 44(4)
  c/nm	1.066 69(5)	1.076 36(3)
  α/(°)	109.841(4)	111.686(3)
  β/(°)	109.098(4)	92.367(3)
  γ/(°)	90.811(3)	108.351(3)
  V/nm3	0.953 01(7)	0.953 36(6)
  F(000)	538	566
  Z	2	2
  Dc/(g·cm-3)	1.920	2.017
  μ/mm-1	10.85	5.13
  θ range/(°)	4.5-77.3	2.1-29.3
  Reflection measured, independent	10 795, 4 052	9 861, 4 161
  Observed reflection [I≥2σ(I)]	3 670	3 220
  Rint	0.028	0.027
  R1 [I≥2σ(I)]	0.033	0.033
  wR2 (all data)	0.087	0.074
  GOF	1.04	1.05

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

  1
  Mn1—O1	0.221 89(19)	Mn1—O1ⅰ	0.221 01(17)	Mn1—O3	0.211 7(2)
  Mn1—O5	0.220 9(2)	Mn1—N1	0.224 7(2)	Mn1—N2	0.223 8(2)
  O1—Mn1ⅰ	0.221 01(17)
  O1—Mn1—O1ⅰ	77.28(7)	N1—Mn1—O1ⅰ	97.79(8)	O1—Mn1—N1	95.38(8)
  O1—Mn1—N2	100.18(7)	N2—Mn1—O1ⅰ	170.69(8)	O3—Mn1—O1	90.37(8)
  O3—Mn1—O1ⅰ	93.92(8)	O3—Mn1—O5	91.21(10)	O3—Mn1—N1	167.85(10)
  O3—Mn1—N2	95.07(9)	O5—Mn1—O1	168.84(8)	O5—Mn1—O1ⅰ	91.58(8)
  O5—Mn1—N1	85.22(9)	O5—Mn1—N2	90.69(9)	N2—Mn1—N1	73.41(9)
  2
  Co1—N1	0.212 0(2)	Co1—N2	0.212 3(2)	Co1—O1	0.212 34(18)
  Co1—O1ⅲ	0.213 17(18)	Co1—O3	0.207 4(2)	Co1—O5	0.213 6(2)
  N1—Co1—N2	78.78(10)	N1—Co1—O1	97.66(8)	N1—Co1—O1ⅲ	98.12(8)
  N1—Co1—O5	83.22(9)	N2—Co1—O1ⅲ	175.06(8)	N2—Co1—O5	90.84(8)
  O1—Co1—N2	98.76(8)	O1—Co1—O1ⅲ	77.75(7)	O1—Co1—O5	170.36(8)
  O5—Co1—O1ⅲ	92.62(8)	O3—Co1—N1	169.90(9)	O3—Co1—N2	93.38(9)
  O3—Co1—O1	89.77(8)	O3—Co1—O1ⅲ	90.12(8)	O3—Co1—O5	90.61(9)
  C1—N1—C12	118.0(3)	C1—N1—Co1	128.7(2)	C12—N1—Co1	112.7(2)
  C10—N2—C11	117.7(3)	C10—N2—Co1	129.0(2)	C11—N2—Co1	113.09(19)
  C13—O1—Co1	132.86(18)	C13—O1—Co1ⅲ	124.55(17)	Co1—O1—Co1ⅲ	102.26(7)
  C17—O3—Co1	130.4(2)	Co1—O5—H11	109.8	Co1—O5—H12	110.2
  Symmetry codes: ⅰ-x, -y+1, -z+1; ⅱ -x+1, -y+1, -z+1; ⅲ -x, -y+2, -z+2 for 1; ⅰ -x+1, -y+1, -z+1; ⅱ -x, -y+2, -z+2; ⅲ -x, -y+1, -z+1 for 2.

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