English

• 0.   Introduction

  Recently, a lot of researchers have focused their researches mainly on the investigation of the structures of transition metal complexes possessing Salen-type ligands and their derivatives^[1-6]. These complexes could be utilized in obtaining optical materials^[7-13], biological systems^[14-22], interesting magnetic properties^[23], fluorescent sensor^[24-36], catalytic activity^[37], and building blocks for supramolecular features^[38-46]. Therefore, the research on Salen-type ligands and their Co(Ⅱ) complexes, without gainsaying, remains a focus of many current investigations.

  Synthesis of Salamo-type ligands when compared with Salen-type ligands, is more important, because the electronic and steric effects of the ligands on Salamo-metal-assisted catalysis may be controlled by the introduction of proper substituents into the benzene rings. The configuration would provide opportunities for a greater structural variation and infinite coordination polymers, which would be expected to lead to novel characteristics. Furthermore, this change could offer better ways to control and monitor polymerization in the context of the infinite coordination polymer structures (different functionality permits the use of different metals in the polymerization process)^[23]. In order to study the structural features and spectral characteristics of transition metal complexes with Salamo-type bisoxime ligands, we herein report two trinuclear Co(Ⅱ) complexes possessing solvent effect with an Salamo-type bisoxime ligand, 4, 4′-dinitro-2, 2′-(1, 2-ethylenedioxybis(nitrilomethylidyne))diphenol (H₂L).

  1.   Experimental

  1.1   Material and general methods

  All chemicals were of analytical reagent grades and were used without further purification. C, H and N analyses were obtained using a GmbH VarioEL V3.00 automatic elemental analysis instrument. Elemental analyses for Co(Ⅱ) were performed by an IRIS ER/S-WP-1 ICP atomic emission spectrometer. IR spectra were recorded on a VERTEX70 FT-IR spectrophotometer (500~4 000 cm^-1), with samples prepared as KBr pellets. Melting points were obtained by the use of an X4 microscopic melting point apparatus produced by Beijing Taike Instrument Limited Company and were uncorrected. Fluorescent spectra were taken on a LS-55 fluorescence photometer. X-ray single crystal structure determinations were carried out on a Bruker Smart Apex CCD diffractometer.

  1.2   Synthesis of the ligand H₂L

  The reaction step involved in the synthesis of H₂L is given in Scheme 1. H₂L was prepared by the modification of the reported method^[47-53]. A mixture of 5-nitrosalicylicaldehyde (341.6 mg, 2.01 mmol) and 1, 2-bis(aminooxy)ethane (93.4 mg, 1.00 mmol) in ethanolic solution was stirred at 55 ℃ for 5 h. After cooling to room temperature, the precipitate was filtered, and washed successively with ethanol and ethanol/hexane (1:4, V/V), respectively. he product was dried under vacuum, and obtained 298.69 mg of colorless micro-crystal. Yield: 85.1%. m.p. 202~203 ℃. Anal. Calcd. for C₁₆H₁₄N₄O₈(%): C, 49.24; H, 3.62; N, 14.35. Found(%): C, 49.23; H, 3.70; N, 14.16.

  图 Scheme 1

  

  图 Scheme 1  Synthetic route to the Salamo-type ligand H₂L

  Figure Scheme 1.  Synthetic route to the Salamo-type ligand H₂L

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  1.3   Synthesis of complex 1

  A dropwise solution of Co(OAc)₂·4H₂O (2.47 mg, 0.01 mmol) in ethanol (4 mL) was added to a solution of H₂L (3.52 mg, 0.01 mmol) in chloroform (4 mL) at room temperature, and the resulting mixed solution immediately turned yellow, and was stirred for 4 h at ambient temperature. The mixed solution was filtered and the filtrate was allowed to stand at room temperature for about three weeks, the solvent was partially evaporated and finally obtained several red prismatic single crystals suitable for X-ray crystallo-graphic analysis. Anal. Calcd. for C₄₆H₅₆C_l6Co₃N₈O₂₄(%) C, 36.97; H, 3.78; N, 7.50; Co, 11.83; Found(%): C, 36.99; H, 3.78; N, 7.47; Co, 11.86.

  1.4   Synthesis of complex 2

  A dropwise solution of Co(OAc)₂·4H₂O (2.47 mg, 0.01 mmol) in n-propanol (3 mL) was added to a solution of H₂L (3.52 mg, 0.01 mmol) in chloroform (3 mL) at room temperature, and the resulting mixed solution immediately turned yellow, and then continued stirring for 4 h at ambient temperature. The mixed solution was filtered and the filtrate was allowed to stand at room temperature for about four weeks, the solvent was partially evaporated and finally obtained several red prismatic single crystals suitable for X-ray crystallographic analysis. Anal. Calcd. for C₄₂H₄₆Co₃N₈O₂₂(%): C, 42.33; H, 3.89; N, 9.40; Co, 14.84. Found(%): C, 42.34; H, 3.89; N, 9.37; Co, 14.81.

  1.5   X-ray crystallography

  The single crystals of complexes 1 and 2 with approximated dimensions of 0.28 mm×0.24 mm×0.22 mm and 0.26 mm×0.24 mm×0.23 mm, respectively, were placed on a Bruker Smart 1000 CCD area detector. The diffraction data were collected using a graphite monochromated Mo Kα radiation (λ=0.071 073 nm) at 298(2) K. The structures were solved by direct method using SHELXS-2014^[54], and refined by full-matrix least-squares method on F² using SHELXL-2014^[54]. Hydrogen atoms were added in their idealized positions. Details of the data collection and refinements are given in Table 1.

  表 1

  

  表 1  Crystal data and structure refinements for complexes 1 and 2

  Table 1.  Crystal data and structure refinements for complexes 1 and 2

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  Complex	1	2
  Empirical formula	C46H56Cl6Co3N8O24	C42H46Co3N8O22
  Formula weight	1 494.48	1 191.66
  Crystal system	Triclinic	Monoclinic
  Space group	P1	P21/c
  a/nm	1.111 93(12)	1.092 54(6)
  b/nm	1.177 21(9)	1.517 22(5)
  c/nm	1.380 91(11)	1.767 84(9)
  α/(°)	69.184(7)	99.992(5)
  β/(°)	69.437(9)
  γ/(°)	81.852(7)
  V/nm3	1.581 6(2)	2.886 0(2)
  Z	1	2
  Dc/(g·cm-3)	1.569	1.371
  μ/mm-1	1.113	0.930
  F(000)	763.0	1 222.0
  θ range/(°)	3.53~26.02	3.52~26.02
  Limiting indices	-13≤h≤9, -14≤k≤14, -17≤l≤16	-7≤h≤13, -18≤k≤11, -20≤l≤21
  Independent reflections	6 196	5 676
  Completeness to θ/%	99.52	99.80
  Data, restraint, parameter	438, 0, 51	363, 0, 27
  GOF on F2	1.034	0.977
  Final R indices [I > 2σ(I)]	R=0.049 1, wR=0.113 2	R=0.057 2, wR=0.116 5
  Largest diff. peak and hole/(e·nm-3)	692 and -812	430 and -362

  CCDC: 1511306, 1; 1511308, 2.

  2.   Results and discussion

  2.1   Crystal structures

  X-ray single crystal structural analysis reveals that through intermolecular hydrogen bonds, complex 1 demonstrated a self-assembling continual zigzag chain supramolecular structure. The molecular structure and monomeric octahedral unit are shown in Fig. 1(a) and 1(b), respectively, while the polymeric representation of the structure is depicted in Fig. 2. Selected bond lengths and angles of complexes 1 and 2 are listed in Table 2. Hydrogen bonding for complexes 1 and 2 are given in Table 3.

  图 1

  

  图 1  (a) Molecular structure of complex 1; (b) Coordination polyhedron of Co(Ⅱ) ions

  Figure 1.  (a) Molecular structure of complex 1; (b) Coordination polyhedron of Co(Ⅱ) ions

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  图 2

  

  图 2  Part of the infinite 1D chain motif of complex 1

  Figure 2.  Part of the infinite 1D chain motif of complex 1

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  表 2

  

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

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

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  1
  Co1-O1	0.204 8(2)	Co2-O1#1	0.212 7(2)	Co1-O11	0.213 2(2)
  Co1-O6	0.207 3(2)	Co1-O2	0.213 3(3)	Co2-O10#1	0.204 9(2)
  Co1-O9	0.206 4(2)	Co2-O6#1	0.213 1(2)	Co1-N3	0.213 0(2)
  Co2-O6	0.213 1(2)	Co2-O10	0.204 9(2)	Co2-O1	0.212 7(2)
  O1-Co1-O6	81.42(9)	O1-Co1-O9	92.22(9)	O1-Co1-O11	88.23(9)
  O1-Co1-O2	86.39(10)	O1-Co1-O3	165.92(11)	O6-Co1-O9	92.98(10)
  O6-Co1-O11	91.74(10)	O6-Co1-O2	167.72(10)	O6-Co1-N3	85.92(10)
  O9-Co1-O11	175.28(10)	O9-Co1-O2	88.92(11)	O9-Co1-N3	94.59(10)
  O11-Co1-O2	86.41(11)	O11-Co1-O3	86.00(10)	N2-Co1-N3	106.03(11)
  O1-Co2-O6	78.27(8)	O1-Co2-O10	86.82(9)	O1-Co2-O1#1	179.999(1)
  O1-Co2-O6#1	101.73(8)	O1-Co2-O10#1	93.18(9)	O6-Co2-O10	89.66(9)
  O6-Co2-O1#1	101.73(8)	O6-Co2-O6#1	180.00	O6-Co2-O10#1	90.34(9)
  O10-Co2-O1#1	93.18(9)	O10-Co2-O6#1	89.66(9)	O10-Co2-O10#1	179.999(1)
  O1#1-Co2-O6#1	78.27(8)	O1#1-Co2-O10#1	86.82(9)	O6#1-Co2-O10#1	90.34(9)
  2
  Co1-O1	0.204 4(3)	Co1-O10	0.204 9(3)	Co2-O1	0.213 2(3)
  Co1-O6	0.205 8(3)	Co1-O2	0.211 9(4)	Co2-O6	0.212 4(2)
  Co1-O9	0.216 6(3)	Co1-O3	0.213 4(4)	Co2-O11	0.203 2(3)
  O6-Co1-O9	89.00(12)	O6-Co1-O2	167.40(13)	O6-Co1-N3	85.08(13)
  O1-Co1-O6	81.40(10)	O1-Co1-O9	89.37(11)	O1-Co1-O10	91.21(11)
  O1-Co1-O2	87.64(12)	O1-Co1-O3	166.27(14)	O10-Co1-O6	93.72(12)
  O10-Co1-O9	177.27(13)	O10-Co1-O2	91.51(13)	O10-Co1-N3	92.03(15)
  O2-Co1-O9	85.87(13)	N2-Co1-N3	106.20(15)	N3-Co1-O9	88.02(15)
  O6-Co2-O6	180.00	O6-Co2-O1#2	102.11(9)	O6-Co2-O1#2	77.89(9)
  O6#2-Co2-O1#2	77.89(9)	O6#2-Co2-O1	102.11(9)	O1-Co2-O1	180.00
  O11-Co2-O6#2	87.37(11)	O11-Co2-O6#2	92.63(11)	O11-Co2-O6	87.37(11)
  O11#2-Co2-O6	92.63(11)	O11-Co2-O1#2	90.57(11)	O11-Co2-O1	89.43(11)
  O11-Co2-O1#2	89.43(11)	O11#2-Co2-O1	90.57(11)	O11-Co2-O11#2	180.00
  Symmetry codes: #1: 1-x, -y, 2-z; #2: 1-x, 2-y, 1-z.

  表 3

  

  表 3  Hydrogen bonding parameters for complexes 1 and 2

  Table 3.  Hydrogen bonding parameters for complexes 1 and 2

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  D-H…A	d(D-H)/nm	d(H…A)/nm	d(D…A)/nm	∠DHA/(°)
  Complex 1
  O11#1-H11#1…O12	0.085	0.187	0.269 8(5)	167
  C8-H8B…O9	0.097	0.244	0.328 1(5)	144
  C9-H9A…O7#2	0.097	0.247	0.3338(6)	149
  O12#3-H12A…O2	0.082	0.218	0.292 0(5)	151
  C15-H15…O10#1	0.093	0.259	0.321 3(4)	124
  C19-H19A…O10#1	0.097	0.252	0.348 7(6)	176
  C21-H21…O9	0.098	0.249	0.339 7(6)	153
  Complex 2
  O9-H9…O3#1	0.085	0.202	0.286 0(8)	172
  C2-H2…O11#2	0.093	0.259	0.321 7(5)	125
  C14-H14…O2#3	0.093	0.259	0.347 3(7)	158
  C19-H19A…O8#3	0.096	0.261	0.355 8(2)	169
  C8-H8A…N3	0.097	0.260	0.295 7(15)	102
  C9-H9A…O10	0.097	0.219	0.308 1(10)	153
  C13-H13…O11#2	0.093	0.257	0.322 5(5)	127
  C17-H17A…O11#2	0.097	0.255	0.350 4(6)	167
  Symmetry codes: #1: 1-x, -y, 2-z; #2: -1+x, y, z; #3: -x, 1-y, 2-z for 1; #1: -x, -1/2+y, 1/2-z; #2: 1-x, 2-y, 1-z; #3: 1-x, -1/2+y, 1/2-z for 2.

  As revealed by the crystal structure, complex 1 crystallizes in the triclinic, space group P1. The complex consists of three Co(Ⅱ) ions, two deprotonated L^2- units, two μ-acetate ions, two coordinated ethanol molecules, and two non-coordinated ethanol and chloroform molecules resulting in a trinuclear Co(Ⅱ) complex. All the hexa-coordinated Co(Ⅱ) ions lie in a slightly distorted octahedron coordination environment. The two terminal Co(Ⅱ) (Co1 and Co1#1) ions are located in the N₂O₂ coordination sphere of L^2-. One oxygen atom (O10) comes from the acetato bridge and the other oxygen atom (O9) comes from the ethanol molecule. The coordination sphere of the central Co(Ⅱ) (Co2) ion contains four phenoxo oxygen atoms (O1, O6, O1#1 and O6#1) from two L^2- and double μ-acetato oxygen atoms (O10 and O10#1) that adopt a similar μ-O-C-O. All the six oxygen atoms that are coordinated to Co2 atom constitute octahedral geometry. As illustrated in Fig. 2, complex 1 is linked by three intermolecular hydrogen bonding interactions to form an infinite 2D supramolecular chain^[55-61].

  X-ray crystallographic analysis reveals that complex 2 crystallizes in the monoclinic system, space group P2₁/c. Fig. 3(a) and 3(b) show the molecular structure and the monomeric octahedral unit of complex 2. Selected bond lengths and angles are provided in Table 2.

  图 3

  

  图 3  (a) Molecular structure of complex 2; (b) Coordination polyhedron of Co(Ⅱ) ions

  Figure 3.  (a) Molecular structure of complex 2; (b) Coordination polyhedron of Co(Ⅱ) ions

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  The complex 2 contains three Co(Ⅱ) ions, two deprotonated L^2- units, two μ-acetate ions, and two coordinated n-propanol molecules as expected from the analytical data. All the hexa-coordinated Co(Ⅱ) ions adopt a slightly distorted octahedron coordination sphere. The two terminal Co(Ⅱ) (Co1 and Co1#2) ions are situated on the N₂O₂ coordination sphere of L^2- with one oxygen (O10) atom from the acetato bridge and another oxygen (O9) atom from the n-propanol molecule. The coordination sphere of the central Co(Ⅱ) (Co2) ion consists of four phenoxo oxygen atoms (O1, O6, O1#2 and O6#2) from two L^2- and double μ-acetato oxygen atoms (O11 and O11#2) that adopt a similar μ-O-C-O. Similar to complex 1, all the six oxygen atoms that are coordinated to Co2(Ⅱ) ion construct an octahedron. And the structure of complex 2 resides in the formation of a 3D supramolecular structure via three intermolecular hydrogen bonding interactions^[62-68] (Fig. 4).

  图 4

  

  图 4  Part of the infinite 3D net motif of complex 2

  Figure 4.  Part of the infinite 3D net motif of complex 2

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  2.2   Solvent effect

  Two Co(Ⅱ) complexes could been synthesized by the reaction of the Salamo-type ligand H₂L with Co(OAc)₂·4H₂O in different solvents. Complexes 1 and 2 present similar stoichiometric ratio when the introduction of different solvent molecules (ethanol or n-propanol). Although the molecule structures of the Co(Ⅱ) complexes obtained in different mixture solutions are similar to each other, the complexes 1 and 2 possess different supramolecular structural features (Table 3, Fig. 2 and 4). As illustrated in Fig. 2, complex 1 is linked by three intermolecular hydrogen bonding interactions to form an infinite 2D supramolecular chain. However, an infinite 3D supramolecular network of complex 2 is formed through three intermolecular hydrogen bonding interactions. The influence of solvent effect is clearly revealed in selected bond distances (nm) and angles (°) for complexes 1 and 2 (Table 2). It is noteworthy that the bond lengths from the oxygen atoms (O11 or O8) of coordinated solvent molecules (ethanol or n-propanol) to the terminal Co(Ⅱ) ions (Co1) in complexes 1 and 2 are 0.212 7(2) and 0.216 2(4) nm, respectively, which do not present a regular elongation when the steric hindrance successively becomes larger from ethanol to n-propanol.

  2.3   IR spectra

  The FT-IR spectra of H₂L and its corresponding Co(Ⅱ) complexes 1 and 2 exhibit various bands in the range of 400~4 000 cm^-1 so as to identify frequencies owing to the Co-O and Co-N bonds. IR spectra of H₂L and its complexes are given in Fig. 5. IR spectra indicate that complexes 1 and 2 have similar structures. The free ligand H₂L shows Ar-O and C=N stretching bands at 1 274 and 1 627 cm^-1, respectively, and are shifted to lower frequencies by ca. 40 and 23 cm^-1 upon complexation. Besides, the O-H stretching bands that appear at 3 405 and 3 448 cm^-1 in complexes 1 and 2 are evidence of the existence of coordinated ethanol and n-propanol molecules, respectively^[53]. The far-infrared spectra of complexes 1 and 2 are also obtained in the region of 500~100 cm^-1 in order to identify frequencies due to the Co-O and Co-N bonds. These assignments are consistent with the frequency values reported in the literature^[48-50].

  图 5

  

  图 5  IR spectra of H₂L and its complexes 1 and 2

  Figure 5.  IR spectra of H₂L and its complexes 1 and 2

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  2.4   UV-Vis absorption spectra

  UV-Vis absorption spectra of the ligand (H₂L) and its corresponding trinuclear Co(Ⅱ) complexes 1 and 2 in DMF solutions at 298 K are shown in Fig. 6. The spectral shapes of the two complexes are similar to one another, and different from the shape of the ligand (H₂L). The UV-Vis spectrum of the free ligand (H₂L) exhibits two absorption peaks at ca. 375 and 448 nm^[47-48]. The former absorption peak could be assigned to the π-π^* transition of the benzene rings and the latter could be attributed to the intra-ligand π-π^* transition of the C=N bonds^[47-51]. Compared with the absorption peak of the ligand, the corresponding absorption peaks at 496 and 498 nm are observed in complexes 1 and 2 which are bathochromically shifted by ca. 48 and 50 nm, indicating the coordination of Co(Ⅱ) ions with the ligand. It is worthy to note that similar pattern in the UV-Vis absorption spectra of complexes 1 and 2 clearly indicate that the structures of the two complexes are alike.

  图 6

  

  图 6  UV-Vis absorption spectra of H₂L and complexes 1 and 2

  Figure 6.  UV-Vis absorption spectra of H₂L and complexes 1 and 2

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  2.5   Fluorescence properties

  The emission spectra of complexes 1 and 2 in dilute DMF solution at ambient temperature are shown in Fig. 7. The complexes 1 and 2 show an intense photoluminescence with maximum emission at ca. 568 and 566 nm, respectively, when excited at 450 nm. Compared with the ligand, strong fluorescence intensity of the Co(Ⅱ) complexes are observed, indicating that fluorescence characteristic has been influenced by the introduction of the Co(Ⅱ) ions^{[48, 51]}.

  图 7

  

  图 7  Fluorescence spectra of complexes 1 and 2

  Figure 7.  Fluorescence spectra of complexes 1 and 2

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  3.   Conclusions

  We have designed and synthesized two supramolecular trinuclear Co(Ⅱ) complexes with a Salamo-type ligand. The Co(Ⅱ) complexes were characterized by physicochemical methods and single-crystal X-ray diffraction. In complex 1, all the three Co(Ⅱ) ions are hexa-coordinated via two deprotonated L^2- units, two μ-acetato anions and two coordinated ethanol molecules. However, the coordination fashion for complex 2 is similar to that of complex 1. In the IR spectra of the two complexes, the (M-O) and (M-N) vibrational absorption bands were observed. Consequently, the O-H stretching bands of complexes 1 and 2 found at 3 405 and 3 448 cm^-1 simply proved the evidence of the coordinated ethanol and n-propanol molecules, respectively. The UV-Vis spectra clearly indicate that the structures of the two Co(Ⅱ) complexes are similar and different from that of the ligand (H₂L). X-ray crystal structures reveal that the structural features of complexes 1 and 2 are very similar except for the differences in the coordinated solvent molecules. Interestingly, the existence of solvent effect in complexes 1 and 2 may be responsible for the slight differences in their crystal and supramolecular structures.

• 1. [1]

     Zhao L, Dang X T, Chen Q, et al. Synth. React. Inorg. Met.-Org. Nano-Metal Chem., 2013, 43:1241-1246 doi: 10.1080/15533174.2012.757236

  2. [2]

     Sun Y X, Zhang S T, Ren Z L, et al. Synth. React. Inorg. Met.-Org. Nano-Metal Chem., 2013, 43:995-1000 doi: 10.1080/15533174.2012.753614

  3. [3]

     Dong X Y, Sun Y X, Wang L, et al. J. Chem. Res., 2012, 36: 387-390 doi: 10.3184/174751912X13366711594575

  4. [4]

     Sun Y X, Gao X H. Synth. React. Inorg. Met.-Org. Nano-Metal Chem., 2011, 41:973-978 doi: 10.1080/15533174.2011.591329

  5. [5]

     Sun Y X, Xu L, Zhao T H, et al. Synth. React. Inorg. Met.-Org. Nano-Metal Chem., 2013, 43:509-513 doi: 10.1080/15533174.2012.740756

  6. [6]

     Dong X Y, Akogun S F, Zhou W M, et al. J. Chin. Chem. Soc., 2017, 64:412-419 doi: 10.1002/jccs.2017.64.issue-4

  7. [7]

     Liu P P, Sheng L, Song X Q, et al. Inorg. Chim. Acta, 2015, 434:252-257 doi: 10.1016/j.ica.2015.05.026

  8. [8]

     Song X Q, Liu P P, Xiao Z R, et al. Inorg. Chim. Acta, 2015, 438:232-244 doi: 10.1016/j.ica.2015.09.022

  9. [9]

     Song X Q, Peng Y J, Chen G Q, et al. Inorg. Chim. Acta, 2015, 427:13-21 doi: 10.1016/j.ica.2014.12.008

  10. [10]

      Song X Q, Liu P P, Liu Y A, et al. Dalton Trans., 2016, 45: 8154-8163 doi: 10.1039/C6DT00212A

  11. [11]

      Song X Q, Wang L, Zheng Q F, et al. Inorg. Chim. Acta, 2012, 391:171-178 doi: 10.1016/j.ica.2012.04.007

  12. [12]

      Liu P P, Wang C Y, Zhang M, et al. Polyhedron, 2017, 129: 133-140 doi: 10.1016/j.poly.2017.03.019

  13. [13]

      Yu T Z, Zhang K, Zhao Y L, et al. Inorg. Chim. Acta, 2008, 361:233-240 doi: 10.1016/j.ica.2007.07.012

  14. [14]

      Wu H L, Bai Y C, Zhang Y H, et al. J. Coord. Chem., 2014, 67:3054-3066 doi: 10.1080/00958972.2014.959507

  15. [15]

      Chen C Y, Zhang J W, Zhang Y H, et al. J. Coord. Chem., 2015, 68:1054-1071 doi: 10.1080/00958972.2015.1007965

  16. [16]

      Wu H L, Bai Y H, Zhang Y H, et al. Z. Anorg. Allg. Chem., 2014, 640:2062-2071 doi: 10.1002/zaac.v640.10

  17. [17]

      Wu H L, Pan G L, Bai Y C, et al. J. Photochem. Photobiol. B, 2014, 135:33-43 doi: 10.1016/j.jphotobiol.2014.04.005

  18. [18]

      Wu L, Pan G L, Bai Y C, et al. J. Chem. Res., 2014, 38: 211-217 doi: 10.3184/174751914X13933417974082

  19. [19]

      Wu H L, Wang C P, Wang F, et al. J. Chin. Chem. Soc., 2015, 62:1028-1034 doi: 10.1002/jccs.v62.11

  20. [20]

      Wu H L, Wang H, Wang X L, et al. New J. Chem., 2014, 38:1052-1061 doi: 10.1039/c3nj01145c

  21. [21]

      Wu H L, Pan G L, Bai Y C, et al. J. Coord. Chem., 2013, 66:2634-2646 doi: 10.1080/00958972.2013.812725

  22. [22]

      Wu H L, Pan G L, Bai Y C, et al. Res. Chem. Intermed., 2015, 41:3375-3388 doi: 10.1007/s11164-013-1440-5

  23. [23]

      Dong W K, Ma J C, Zhu L C, et al. Cryst. Growth Des., 2016, 16:6903-6915 doi: 10.1021/acs.cgd.6b01067

  24. [24]

      Hu J H, Sun Y, Qi J, et al. Spectrochim. Acta A, 2017, 175: 125-133 doi: 10.1016/j.saa.2016.12.009

  25. [25]

      Hu J H, Li J B, Qi J, et al. New J. Chem., 2015, 39:843-848 doi: 10.1039/C4NJ01147C

  26. [26]

      Sun Y, Hu J H, Qi J, et al. Spectrochim. Acta A, 2016, 167: 101-105 doi: 10.1016/j.saa.2016.05.017

  27. [27]

      胡京汉, 颜农平, 陈娟娟, 等.高等学校化学学报, 2013, 34(6):1368-1373 doi: 10.7503/cjcu20120875HU Jing-Han, YAN Nong-Ping, CHEN Juan-Juan, et al. Chem. J. Chinese Universities, 2013, 34(6):1368-1373 doi: 10.7503/cjcu20120875

  28. [28]

      Hu J H, Li J B, Qi J, et al. New J. Chem., 2014, 39:843-848 http://pubs.rsc.org/en/Content/ArticleLanding/2015/NJ/C4NJ01147C#!divAbstract

  29. [29]

      Li J B, Hu J H, Chen J J, et al. Spectrochim. Acta A, 2014, 133:773-777 doi: 10.1016/j.saa.2014.06.060

  30. [30]

      Hu J H, Li J B, Qi J, et al. Sens. Actuators B, 2015, 208: 581-587 doi: 10.1016/j.snb.2014.11.066

  31. [31]

      Hu J H, Li J B, Qi J, et al. New J. Chem., 2015, 39:4041-4046 doi: 10.1039/C5NJ00089K

  32. [32]

      胡京汉, 陈娟娟, 李建斌, 等.无机化学学报, 2014, 30(11):2544-2548 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20141113&journal_id=wjhxxbcnHU Jing-Han, CHEN Juan-Juan, LI Jian-Bin, et al. Chinese J. Inorg. Chem., 2014, 30(11):2544-2548 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20141113&journal_id=wjhxxbcn

  33. [33]

      Qi J, Hu J H, Chen J J, et al. Curr. Anal. Chem., 2016, 12: 119-123 doi: 10.2174/1573411011666150827194259

  34. [34]

      Hu J H, Li J B, Qi J, et al. Phosphorus Sulfur Silicon Relat. Elem., 2016, 191:984-987 doi: 10.1080/10426507.2015.1050016

  35. [35]

      Hu J H, Sun Y, Qi J, et al. RSC Adv., 2016, 6:100401-100406 doi: 10.1039/C6RA16378E

  36. [36]

      Hu J H, Yan N P, Chen J J. J. Chem. Res., 2012, 36:619-622 doi: 10.3184/174751912X13463433858357

  37. [37]

      Li L H, Dong W K, Zhang Y, et al. Appl. Organomet. Chem., 2017:DOI: 10.1002/aoc.3818

  38. [38]

      Chai L Q, Wang G, Sun Y X, et al. J. Coord. Chem., 2012, 65:1621-1631 doi: 10.1080/00958972.2012.677836

  39. [39]

      Chai L Q, Huang J J, Zhang H S, et al. Spectrochim. Acta A, 2014, 131:526-533 doi: 10.1016/j.saa.2014.04.127

  40. [40]

      Chai L Q, Liu G, Zhang J Y, et al. J. Coord. Chem., 2013, 66:3926-3938 doi: 10.1080/00958972.2013.857016

  41. [41]

      Chai L Q, Zhang H S, Huang J J, et al. Spectrochim. Acta A, 2015, 137:661-669 doi: 10.1016/j.saa.2014.08.084

  42. [42]

      Chai L Q, Tang L J, Chen L C, et al. Polyhedron, 2017, 122: 228-240 doi: 10.1016/j.poly.2016.11.032

  43. [43]

      Chai L Q, Zhang K Y, Tang L J, et al. Polyhedron, 2017, 130: 100-107 doi: 10.1016/j.poly.2017.04.010

  44. [44]

      Xu L, Zhu L C, Ma J C, et al. Z. Anorg. Allg. Chem., 2015, 641:2520-2524 doi: 10.1002/zaac.201500619

  45. [45]

      董文魁, 吕忠武, 孙银霞, 等.无机化学学报, 2009, 25(9):1627-1634 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20090920&journal_id=wjhxxbcnDONG Wen-Kui, LÜ Zhong-Wu, SUN Yin -Xia, et al. Chinese J. Inorg. Chem., 2009, 25(9):1627-1634 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20090920&journal_id=wjhxxbcn

  46. [46]

      Wang L, Ma J C, Dong W K, et al. Z. Anorg. Allg. Chem., 2016, 42:834-839 doi: 10.1002/zaac.201600125/pdf

  47. [47]

      Dong W K, Zheng S S, Zhang J T, et al. Spectrochimi. Acta A, 2017, 184:141-150 doi: 10.1016/j.saa.2017.04.061

  48. [48]

      Zheng S S, Dong W K, Zhang Y, et al. New J. Chem., 2017, 41:4966-4973 doi: 10.1039/C6NJ04090J

  49. [49]

      Pu L M, Long H T, Zhang Y, et al. Polyhedron, 2017, 128: 57-67 doi: 10.1016/j.poly.2017.02.033

  50. [50]

      Hao J, Li L L, Zhang J T, et al. Polyhedron, 2017, 134:1-10 doi: 10.1016/j.poly.2017.05.060

  51. [51]

      Li X Y, Chen L, Gao L, et al. RSC Adv., 2017, 7:35905-35916 doi: 10.1039/C7RA06796H

  52. [52]

      Dong W K, Zhu L C, Ma J C, et al. Inorg. Chim. Acta, 2016, 453:402-408 doi: 10.1016/j.ica.2016.08.050

  53. [53]

      Dong W K, He X N, Yan H B, et al. Polyhedron, 2009, 28: 1419-1428 doi: 10.1016/j.poly.2009.03.017

  54. [54]

      Sheldrick G M. SHELX-97, Program for the Solution and the Refinement of Crystal Structures, University of Göttingen, Germany, 1997.

  55. [55]

      Chen L, Dong W K, Zhang H, et al. Cryst. Growth Des., 2017, 17:3636-3648 doi: 10.1021/acs.cgd.6b01860

  56. [56]

      Tao C H, Ma J C, Zhu L C, et al. Polyhedron, 2017, 128:38-45 doi: 10.1016/j.poly.2017.02.040

  57. [57]

      Dong W K, Zhu L C, Dong Y J, et al. Polyhedron, 2016, 117:148-154 doi: 10.1016/j.poly.2016.05.055

  58. [58]

      Wang P, Zhao L. Spectrochim. Acta A, 2015, 135:342-350 doi: 10.1016/j.saa.2014.06.129

  59. [59]

      Sun Y X, Wang L, Dong X Y, et al. Synth. React. Inorg. Met.-Org. Nano-Metal Chem., 2013, 43:599-603 doi: 10.1080/15533174.2012.751424

  60. [60]

      Song X Q, Cheng G Q, Wang X R, et al. Inorg. Chim. Acta, 2015, 425:145-153 doi: 10.1016/j.ica.2014.09.028

  61. [61]

      Dong Y J, Ma J C, Zhu L C, et al. J. Coord. Chem., 2017, 70:103-115 doi: 10.1080/00958972.2016.1262537

  62. [62]

      Dong Y J, Dong X Y, Dong W K, et al. Polyhedron, 2017, 123:305-315 doi: 10.1016/j.poly.2016.12.010

  63. [63]

      董文魁, 冯建华, 张玉洁, 等.无机化学学报, 2011, 27(9):1865-1870 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20110932&journal_id=wjhxxbcnDONG Wen-Kui, FENG Jian-Hua, ZHANG Yu-Jie, et al. Chinese J. Inorg. Chem., 2011, 27(9):1865-1870 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20110932&journal_id=wjhxxbcn

  64. [64]

      Zhao L, Wang L, Sun Y X, et al. Synth. React. Inorg. Met.-Org. Nano-Metal Chem., 2012, 42:1303-1308 doi: 10.1080/15533174.2012.684235

  65. [65]

      Dong X Y, Kang Q P, Jin B X, et al. Z. Naturforsch., B: Chem. Sci., 2017, 72:415-420 https://www.degruyter.com/view/j/znb.2017.72.issue-6/znb-2016-0268/znb-2016-0268.xml

  66. [66]

      董文魁, 王莉, 孙银霞, 等.无机化学学报, 2011, 27(2):372-376 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20110228&journal_id=wjhxxbcnDONG Wen-Kui, WANG Li, SUN Yin-Xia, et al. Chinese J. Inorg. Chem., 2011, 27(2):372-376 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20110228&journal_id=wjhxxbcn

  67. [67]

      Wang P, Zhao L. Synth. React. Inorg. Met.-Org. Nano-Metal Chem., 2016, 46:1095-1101 doi: 10.1080/15533174.2015.1004416

  68. [68]

      董文魁, 唐晓璐, 何雪妮, 等.无机化学学报, 2009, 25(3):528-532 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20090328&journal_id=wjhxxbcnDONG Wen-Kui, TANG Xiao-Lu, HE Xue -Ni, et al. Chinese J. Inorg. Chem., 2009, 25(3):528-532 http://www.wjhxxb.cn/wjhxxbcn/ch/reader/view_abstract.aspx?flag=1&file_no=20090328&journal_id=wjhxxbcn

• 

  Scheme 1  Synthetic route to the Salamo-type ligand H₂L

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  Figure 1  (a) Molecular structure of complex 1; (b) Coordination polyhedron of Co(Ⅱ) ions

  Thermal ellipsoids at 30% probability; Hydrogen atoms are omitted for clarity; Symmetry codes: #1: 1-x, -y, 2-z

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  Figure 2  Part of the infinite 1D chain motif of complex 1

  Symmetry codes: #1: 1-x, -y, 2-z; #2:-1+x, y, z; #3:-x, 1-y, 2-z

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  Figure 3  (a) Molecular structure of complex 2; (b) Coordination polyhedron of Co(Ⅱ) ions

  Thermal ellipsoids at 30% probability; Hydrogen atoms are omitted for clarity; Symmetry codes: #2: 1-x, 2-y, 1-z

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  Figure 4  Part of the infinite 3D net motif of complex 2

  Symmetry codes: #1:-x, -1/2+y, 1/2-z; #3: 1-x, -1/2+y, 1/2-z

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  Figure 5  IR spectra of H₂L and its complexes 1 and 2

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  Figure 6  UV-Vis absorption spectra of H₂L and complexes 1 and 2

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  Figure 7  Fluorescence spectra of complexes 1 and 2

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  Table 1.  Crystal data and structure refinements for complexes 1 and 2

  Complex	1	2
  Empirical formula	C46H56Cl6Co3N8O24	C42H46Co3N8O22
  Formula weight	1 494.48	1 191.66
  Crystal system	Triclinic	Monoclinic
  Space group	P1	P21/c
  a/nm	1.111 93(12)	1.092 54(6)
  b/nm	1.177 21(9)	1.517 22(5)
  c/nm	1.380 91(11)	1.767 84(9)
  α/(°)	69.184(7)	99.992(5)
  β/(°)	69.437(9)
  γ/(°)	81.852(7)
  V/nm3	1.581 6(2)	2.886 0(2)
  Z	1	2
  Dc/(g·cm-3)	1.569	1.371
  μ/mm-1	1.113	0.930
  F(000)	763.0	1 222.0
  θ range/(°)	3.53~26.02	3.52~26.02
  Limiting indices	-13≤h≤9, -14≤k≤14, -17≤l≤16	-7≤h≤13, -18≤k≤11, -20≤l≤21
  Independent reflections	6 196	5 676
  Completeness to θ/%	99.52	99.80
  Data, restraint, parameter	438, 0, 51	363, 0, 27
  GOF on F2	1.034	0.977
  Final R indices [I > 2σ(I)]	R=0.049 1, wR=0.113 2	R=0.057 2, wR=0.116 5
  Largest diff. peak and hole/(e·nm-3)	692 and -812	430 and -362

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

  1
  Co1-O1	0.204 8(2)	Co2-O1#1	0.212 7(2)	Co1-O11	0.213 2(2)
  Co1-O6	0.207 3(2)	Co1-O2	0.213 3(3)	Co2-O10#1	0.204 9(2)
  Co1-O9	0.206 4(2)	Co2-O6#1	0.213 1(2)	Co1-N3	0.213 0(2)
  Co2-O6	0.213 1(2)	Co2-O10	0.204 9(2)	Co2-O1	0.212 7(2)
  O1-Co1-O6	81.42(9)	O1-Co1-O9	92.22(9)	O1-Co1-O11	88.23(9)
  O1-Co1-O2	86.39(10)	O1-Co1-O3	165.92(11)	O6-Co1-O9	92.98(10)
  O6-Co1-O11	91.74(10)	O6-Co1-O2	167.72(10)	O6-Co1-N3	85.92(10)
  O9-Co1-O11	175.28(10)	O9-Co1-O2	88.92(11)	O9-Co1-N3	94.59(10)
  O11-Co1-O2	86.41(11)	O11-Co1-O3	86.00(10)	N2-Co1-N3	106.03(11)
  O1-Co2-O6	78.27(8)	O1-Co2-O10	86.82(9)	O1-Co2-O1#1	179.999(1)
  O1-Co2-O6#1	101.73(8)	O1-Co2-O10#1	93.18(9)	O6-Co2-O10	89.66(9)
  O6-Co2-O1#1	101.73(8)	O6-Co2-O6#1	180.00	O6-Co2-O10#1	90.34(9)
  O10-Co2-O1#1	93.18(9)	O10-Co2-O6#1	89.66(9)	O10-Co2-O10#1	179.999(1)
  O1#1-Co2-O6#1	78.27(8)	O1#1-Co2-O10#1	86.82(9)	O6#1-Co2-O10#1	90.34(9)
  2
  Co1-O1	0.204 4(3)	Co1-O10	0.204 9(3)	Co2-O1	0.213 2(3)
  Co1-O6	0.205 8(3)	Co1-O2	0.211 9(4)	Co2-O6	0.212 4(2)
  Co1-O9	0.216 6(3)	Co1-O3	0.213 4(4)	Co2-O11	0.203 2(3)
  O6-Co1-O9	89.00(12)	O6-Co1-O2	167.40(13)	O6-Co1-N3	85.08(13)
  O1-Co1-O6	81.40(10)	O1-Co1-O9	89.37(11)	O1-Co1-O10	91.21(11)
  O1-Co1-O2	87.64(12)	O1-Co1-O3	166.27(14)	O10-Co1-O6	93.72(12)
  O10-Co1-O9	177.27(13)	O10-Co1-O2	91.51(13)	O10-Co1-N3	92.03(15)
  O2-Co1-O9	85.87(13)	N2-Co1-N3	106.20(15)	N3-Co1-O9	88.02(15)
  O6-Co2-O6	180.00	O6-Co2-O1#2	102.11(9)	O6-Co2-O1#2	77.89(9)
  O6#2-Co2-O1#2	77.89(9)	O6#2-Co2-O1	102.11(9)	O1-Co2-O1	180.00
  O11-Co2-O6#2	87.37(11)	O11-Co2-O6#2	92.63(11)	O11-Co2-O6	87.37(11)
  O11#2-Co2-O6	92.63(11)	O11-Co2-O1#2	90.57(11)	O11-Co2-O1	89.43(11)
  O11-Co2-O1#2	89.43(11)	O11#2-Co2-O1	90.57(11)	O11-Co2-O11#2	180.00
  Symmetry codes: #1: 1-x, -y, 2-z; #2: 1-x, 2-y, 1-z.

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  Table 3.  Hydrogen bonding parameters for complexes 1 and 2

  D-H…A	d(D-H)/nm	d(H…A)/nm	d(D…A)/nm	∠DHA/(°)
  Complex 1
  O11#1-H11#1…O12	0.085	0.187	0.269 8(5)	167
  C8-H8B…O9	0.097	0.244	0.328 1(5)	144
  C9-H9A…O7#2	0.097	0.247	0.3338(6)	149
  O12#3-H12A…O2	0.082	0.218	0.292 0(5)	151
  C15-H15…O10#1	0.093	0.259	0.321 3(4)	124
  C19-H19A…O10#1	0.097	0.252	0.348 7(6)	176
  C21-H21…O9	0.098	0.249	0.339 7(6)	153
  Complex 2
  O9-H9…O3#1	0.085	0.202	0.286 0(8)	172
  C2-H2…O11#2	0.093	0.259	0.321 7(5)	125
  C14-H14…O2#3	0.093	0.259	0.347 3(7)	158
  C19-H19A…O8#3	0.096	0.261	0.355 8(2)	169
  C8-H8A…N3	0.097	0.260	0.295 7(15)	102
  C9-H9A…O10	0.097	0.219	0.308 1(10)	153
  C13-H13…O11#2	0.093	0.257	0.322 5(5)	127
  C17-H17A…O11#2	0.097	0.255	0.350 4(6)	167
  Symmetry codes: #1: 1-x, -y, 2-z; #2: -1+x, y, z; #3: -x, 1-y, 2-z for 1; #1: -x, -1/2+y, 1/2-z; #2: 1-x, 2-y, 1-z; #3: 1-x, -1/2+y, 1/2-z for 2.

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•