English

• 0.   Introduction

  Much attention has been focused on new functional supramolecular complexes assembled by covalent bonds and non-covalent forces, such as hydrogen bonds and π … π interactions^[1-4]. The interest comes from their fascinating structural features and potential applications in catalysis, separation, gas storage, luminescence, magnetism, lithium-ion batteries, information storage and so forth^[5-10]. Pyrazolecarboxylic acids, such as 1H-pyrazole-4 -carboxylic acid, 3-methyl-1H-pyrazole-4-carboxylic acid, 3, 4-pyrazoledicarboxylic acid, 3, 5-pyrazoledicarboxylic acid and 5-methyl-1H-pyrazole-3-carboxylic acid (H₂MPCA) have emerged as a kind of promising ligands for the design of supramolecular complexes due to its good coordination abilities in multi-coordination modes by the N and O donor atoms on the pyrazole rings and the carboxylic groups^[11-19]. The nitrogen atoms and carboxylic oxygen atoms can not only coordinate with metal ions to form monodentate and/or multidentate M—N and M—O bonds, but also act as a donor and/or acceptor and provide intermolecular hydrogen bond interactions for assembling the complexes into high-dimensional supramolecular networks. Among which, H₂MPCA consists of a pyrazole ring and its carboxyl and methyl groups could form various complexes with interesting structures^[19-28], in which, the HMPCA^-/MPCA^2- anions exhibit many different coordination modes: N, O-chelating fashion, O, O′-chelating mode, μ₂ -κN, O: κO mode, μ₂-κN, O: κO, O′ mode, μ₂ -κN, O: κN′ mode and μ₃ -κN, O: κO, O′: κO′ mode. On the other hand, the N ancillary ligand, 2, 2′-bipyridine (2, 2′-bpy), was also utilized in the synthesis processes of supramolecular complexes, which not only can adjust the coordination structures by occupied the terminal position^[29-30], but also affect the supramolecular structures by involved in hydrogen bonds and π … π interactions. But only one Cd(Ⅱ) complex [Cd(HMPCA)₂(2, 2′-bpy)]·2H₂O^[24] and a Cu(Ⅱ) complex [Cu₂(4, 4′-bpy)₂(2, 2′ -bpy) (MPCA)₂] ·6H₂O^[22] constructed from H₂MPCA and 2, 2′-bpy ligands have been reported. As the continuation of our research in constructing functional metal complexes containing pyrazolecarboxylic acids^{[14-15, 24-28]}, two new transition metal complexes, [Mn(HMPCA)₂(H₂O)₂] (1) and [Ni(HMPCA)₂ (2, 2′-bpy)]·2H₂O (2) have been synthesized through the self-assembly of H₂MPCA with corresponding metal salts in the absence/presence of chelating N ligand, 2, 2′-bpy. In this paper, the syntheses, crystal structures, electrochemical and luminescent properties of complexes 1 and 2 were described.

  1.   Experimental

  1.1   Materials and methods

  All solvents and starting materials for the syntheses were purchased commercially and were used as received. H₂MPCA was prepared following the literature methods^{[21, 31]}. The elemental analyses (C, H and N) were performed on a Perkin-Elmer 2400 Series Ⅱ element analyzer. FTIR spectra were recorded on a Nicolet 460 spectrophotometer in the form of KBr pellets. Powder X-ray diffraction (PXRD) determinations were performed on an X-ray diffractometer (D/max 2500 PC, Rigaku) with Cu Kα radiation (λ = 0.154 06 nm). The operating voltage and current were 60 kV and 300 mA, respectively, and the measurements were carried out over a 2θ range of 3° ~80°. Singlecrystal X-ray diffraction measurements of 1 and 2 were performed on a Bruker Apex Ⅱ diffractometer at 293(2) K. Thermogravimetric analyses (TGA) were carried out on a Dupont thermal analyzer from room temperature to 800 ℃ under N₂ atmosphere at a heating rate of 10 ℃ ·min^-1. Cyclic voltammogram (CV) curves were recorded on a CHI 660D electrochemical workstation. The luminescent spectra were recorded at room temperature on a Sahimadzu RF-5301PC fluorescence spectrofluorometer.

  1.2   Preparation of [Mn(HMPCA)₂(H₂O)₂] (1)

  A solution of H₂MPCA (0.025 2 g, 0.20 mmol) in 4 mL EtOH was mixed with an aqueous solution (5 mL) of MnCl₂·4H₂O (0.019 7 g, 0.10 mmol). After stirred for 2 h, the solution was filtered, and the filtrate was allowed to stand at ambient temperature for one week. Colorless block crystals of 1 suitable for X-ray diffraction analysis were obtained. Yield: 68% (0.023 2 g, based on Mn). Elemental analysis Calcd. for C₁₀H₁₄MnN₄O₆(%): C, 35.20; H, 4.10; N, 16.41. Found (%): C, 35.38; H, 4.28; N, 16.70. IR (KBr disk, cm^-1): 3 410 (m), 3 172 (m), 3 140 (m), 3 084 (m), 2 974 (m), 2 942 (m), 2 857 (m), 1 629 (vs), 1 567 (s), 1 503 (w), 1 426 (s), 1 384 (w), 1 335 (s), 1 293 (s), 1 112 (w), 1 020 (s), 859 (m), 816 (m), 683 (m), 648 (w), 572 (w), 466 (m).

  1.3   Preparation of [Ni(HMPCA)₂(2, 2′‑bpy)]·2H₂O (2)

  H₂MPCA (0.025 2 g, 0.20 mmol), Ni(OAc)₂·4H₂O (0.049 8 g, 0.20 mmol), KOH (0.022 4 g, 0.40 mmol) and 2, 2′-bpy (0.031 2 g, 0.20 mmol) were dissolved in 10 mL deionized water. After stirring for 30 min, the resulting green suspension was placed into a 25 mL Teflon-lined autoclave and heated at 180 ℃ for one day, then cooled to room temperature at a rate of 5 ℃·h^-1. After filtration, the product was washed with distilled water and then dried in vacuo, then purple crystals of 2 suitable for X-ray diffraction analysis were obtained. Yield: 65% (0.032 6 g, based on H₂MPCA). Elemental analysis Calcd. for C₂₀H₂₂N₆O₆Ni(%): C, 47.93; H, 4.39; N, 16.76. Found(%): C, 47.90; H, 4.18; N, 16.50. IR (KBr disk, cm^-1): 3 423 (s), 3 166 (s), 3 140 (s), 3 074(s), 2 932 (s), 2 857 (m), 1 626(vs), 1 566 (s), 1 494 (s), 1 425 (s), 1 274 (s), 1 206 (w), 1 149 (m), 1 025 (s), 838 (m), 776 (s), 714 (s), 645 (m), 563 (m), 446 (w).

  1.4   X‑ray crystallography

  The structures were solved by direct methods using the program SHELXS-2013 and refined with SHELXL -2013^[32]. Anisotropic thermal factors were assigned to all the non-hydrogen atoms. H atoms attached to C were placed geometrically and allowed to ride during subsequent refinement with an isotropic displacement parameter fixed at 1.2 times U_eq of the parent atoms. All other hydrogen atoms bonded to O or N atoms were located from difference Fourier maps and refined with isotropic thermal parameters 1.5 times those of their carrier atoms. The crystallographic data and refinement parameters for 1 and 2 are listed in Table 1.

  Table 1

  

  Table 1.  Crystallographic data and refinement parameters for complexes 1 and 2

  下载: 导出CSV

  Complex	1	2
  Empirical formula	C10H14O6Mn	C20H22O6Ni
  Formula weight	341.19	501.14
  Crystal size/mm	0.24×0.22×0.20	0.26×0.24×0.24
  Crystal system	Trigonal	Monoclicnic
  Space group	R3c	P21/c
  a/nm	1.512 6(5)	1.667 3(3)
  b/nm	1.512 6(5)	1.519 7(3)
  c/nm	3.154 2(9)	0.911 0(2)
  β/(°)		104.99
  V/nm3	6.250(5)	2.229 7(8)
  Z	18	4
  Dc/(g·cm-3)	1.632	1.493
  F(000)	3 150	1 040
  μ(Mo Kα) /mm-1	0.984	0.92
  Independent reflection (Rint)	1 225 (0.117 3)	5 126 (0.074 1)
  Data, restraint, parameter	1 225, 2, 104	5 126, 4, 300
  Goodness-of-fit on F2	1.169	0.941
  R1, wR2 [I > 2σ(I)]	0.041 7, 0.105 8	0.045 2, 0.078 9
  R1, wR2 (all data)	0.053 4, 0.110 6	0.103 5, 0.096 0
  Largest diff. peak and hole/(e·nm-3)	632 and -1 663	355 and -353

  2.   Results and discussion

  2.1   Synthesis

  Treatment of MnCl₂·4H₂O and H₂MPCA in 1∶2 molar ratio with 9 mL mixed solvent of EtOH and H₂O (4∶5, V/V) afforded a colorless solution. Colorless bulk crystals of 1 were isolated from solvent evaporation at room temperature. When the 2, 2′-bpy ligand was introduced, purple crystals of Ni(Ⅱ) complex 2 were synthesized by hydrothermally reaction of Ni(OAc)₂ ·4H₂O, H₂MPCA, 2, 2′-bpy and KOH in 1∶1∶1∶2 molar ratio at 180 ℃ for one day. Complexes 1 and 2 were relatively air- and moisture-stable. The elemental analyses of 1 and 2 were consistent with their chemical formulae. The identities of 1 and 2 were finally confirmed by X-ray crystallography.

  2.2   Infrared spectrum

  In the IR spectra of 1 and 2, the strong and broad absorption bands around 3 200~3 600 cm^-1 region in them are assigned as characteristic peaks of O—H vibration, indicating that water molecules exist in them. The sharp bands at 3 140 cm^-1 in 1 and 2 are assigned to N—H vibration. The absence of absorption peaks in a range of 1 690~1 730 cm^-1 show that all carboxylic groups are deprotonated in 1 and 2. Strong peaks at 1 629 cm^-1 (1), 1 626 cm^-1 (2) and 1 426 cm^-1 (1), 1 425 cm^-1 (2) may be assigned to the ν_as(OCO) and ν_s(OCO) stretching vibration of HMPCA^- ligand. The intense bands at 1 330~1 360 cm^-1 are ascribed to the conjugated C=N stretching vibration.

  2.3   Crystal structure description of 1

  X-ray crystal structure analysis reveals that 1 is a porous supramolecular complex constructed from hydrogen bonds, with effective volume (0.233 6 nm³) in the unit cell. Complex 1 crystallizes in trigonal space group R3c. The asymmetric unit of 1 contains one half Mn(Ⅱ) ion, one HMPCA^- ligand, and one coordination H₂O molecule. As shown in Fig. 1a, the coordination sphere of each Mn(Ⅱ) ion is defined by two oxygen atoms (O1 and O1^ⅰ) and two nitrogen atoms (N1 and N1^ⅰ) from two HMPCA^- ligands as well as two oxygen atoms (O3 and O3^ⅰ) from two H₂O molecules, leading to an octahedral geometry. The bond angles of O1—Mn1—O1^ⅰ, O3^ⅰ—Mn1—O1^ⅰ, O3—Mn1—O3^ⅰ and O3—Mn1—O1 are added up to 362° (Table S1, Supporting information), showing that O1, O1^ⅰ, O3 and O3^ⅰ atoms are in the equatorial position. Moreover, the bond angles of O3—Mn1—O1^ⅰ, N1—Mn1—N1^ⅰ and O3^ⅰ—Mn1—O1 are 167.44(7)°, 162.71(9)° and 167.44(7)°, respectively, deviating from 180°, further indicating that the geometries around each metal center all display distorted octahedral geometry. In complex 1, the bond lengths of Mn1—O1 (0.217 6(2) nm) and Mn1—O3 (0.214 0(19) nm) are shorter than that of Mn1—N1 (0.223 54(18) nm), indicating that the strength of Mn(Ⅱ) ion coordinating with nitrogen atom from HMPCA^- ligand is weaker than that with oxygen atoms from HMPCA^- ligand or H₂O molecule. The lengths of Mn—O_HMPCA (0.217 62(17) nm) and Mn—N_HMPCA (0.223 54(18) nm) bonds around the Mn(Ⅱ) ion are comparable with those observed in other complexes, such as [Mn(HMPCA)₂(phen)]·2H₂O (Mn—O_HMPCA 0.215 72(18) nm; Mn—N_HMPCA 0.224 3(2) nm) ^[26]. As a bidentate ligand, the HMPCA^- anion chelates one Mn(Ⅱ) ion with a pyrazole N atom and a carboxylate O atom to form a five membered ring of Mn1-O1-C5-C4-N1.

  Figure 1

  

  Figure 1.  (a) Molecular structure of 1 with thermal ellipsoid at 30% probability level, where the hydrogen atoms attached to C atoms are omitted for clarity; (b) Two types of intermolecular hydrogen bonding interactions in 1, where only hydrogen atoms involved in the hydrogen bonds are shown; (c) 1D nanotube structure in 1 viewed along c axis; (d) Perspective view of 3D supramolecular structure with 1D channels of 1

  Hydrogen bonds are indicated by dash lines; Symmetry codes: ^ⅰ 1/3+y, -1/3+x, 1/6-z; ^ⅱ 2/3-x+y, 1/3+y, -1/6+z; ^ⅲ 2/3-x, 1/3-y, 1/3-z; ^ⅳ 2/3+y, 1/3-x+y, 1/3-z

  下载: 全尺寸图片 幻灯片

  In addition, there are two types of intermolecular hydrogen bonds in 1: (ⅰ) hydrogen bonds between the oxygen atoms (donor) from coordinated water molecules and oxygen atoms (acceptor) from HMPCA^- ligands: O3—H3X…O2^ⅲ and O3—H3Y…O2^ⅳ (Fig. 1b, Table S2); (ⅱ) hydrogen bonds of the uncoordinated nitrogen atoms (donor) of HMPCA^- ligands with oxygen atoms (acceptor) from HMPCA^-ligands: N2—H2…O1^ⅱ and N2—H2…O2^ⅱ. As shown in Fig. 1d, by the function of these N—H…O and O—H…O hydrogen bond interactions, the adjacent [Mn(HMPCA)₂(H₂O)₂] units are packed into an interesting 3D microporous framework with 1D nanotube structure (Fig. 1c), and the nanotube radius is about 0.164 0(8) nm.

  2.4   Crystal structure description of 2

  The single-crystal X-ray diffraction analysis reveals that complex 2 crystallizes in monoclinic P2₁/c space group. As shown in Fig. 2a, the asymmetric unit of 2 consists of one Ni(Ⅱ) cation, two HMPCA^- anions, one 2, 2′-bpy ligand and two lattice water molecules. Each Ni(Ⅱ) ion locates in a distorted octahedral geometry, hexa-coordinated by two oxygen atoms (O1 and O3) and two nitrogen atoms (N1 and N3) from two HMPCA^- ligands, another two nitrogen atoms (N5 and N6) from one 2, 2′-bpy molecule. The bond angles of O1—Ni1—N1, O3—Ni1—N1, O3—Ni1—N6 and N6—Ni1—O1 are added up to 360.7° (Table S1), showing that O1, N1, O3 and N6 atoms are in the equatorial position. Moreover, the bond angle of N5—Ni1—N3 is 171.2(1)°, deviating from 180°, indicating that the geometry around Ni1 center displays distorted octahedral geometry. The mean Ni—O_HMPCA bond distance (0.207 6(1) nm) and the mean Ni—N_HMPCA bond distance (0.205 7(2) nm), are very close to those in the mononuclear complex [Ni(HMPCA)₂(H₂O)₂] (0.207 4(2) and 0.206 6(3) nm) ^[25]. The mean Ni—N_bpy distance is 0.206 0(2) nm, and the bond angles around Ni(Ⅱ) are in a range of 78.11(9)°~171.18(1)°.

  Figure 2

  

  Figure 2.  (a) Coordination environment of Ni(Ⅱ) ion in 2 with thermal ellipsoid at 30% probability level, where lattice water molecules and the hydrogen atoms attached to C atoms are omitted for charity; (b) Intermolecular hydrogen bonding interactions in 2, where the 2, 2′-bpy ligand coordinated to Ni1 is omitted for clarity; (c) 1D chain structure constructed by O—H…O and N—H…O hydrogen bonds in 2; (d) π…π interactions between the pyridyl groups of the 2, 2′-bpy ligands; (e) 3D supramolecular structure in 2 constructed by hydrogen bonds and π…π interactions

  Only hydrogen atoms involved in the hydrogen bonds are shown; Hydrogen bonds and π…π interactions are indicated by dashed lines; Symmetry codes: ^ⅰ-1+x, -1+y, z; ^ⅱ 1-x, -y, 1-z; ^ⅵ x, y, 1+z; ^ix x, 1/2-y, 1/2+z; ^ⅹ x, 1/2-y, 1/2+z

  下载: 全尺寸图片 幻灯片

  As a bidentate ligand, HMPCA^- and 2, 2′-bpy both act as chelating ligands in 2. Meanwhile, the HMPCA^- ligand act as proton donor and acceptor, and provide two kinds of intermolecular hydrogen bonds: (ⅰ) N—H…O hydrogen bonds between uncoordinated pyrazole ring N atoms and lattice H₂O molecules: N2—H2…O5^ⅰ (N2…O5^ⅰ 0.274 2(4) nm), N4—H4…O6^ⅱ (N4 …O6^ⅱ 0.269 8(4) nm) (Fig. 2b, Table S2); (ⅱ) O—H…O intermolecular hydrogen bonds between oxygen atoms (donor) from lattice water molecules and oxygen atoms (acceptor) from HMPCA^- ligands, O5—H5X…O4^ⅲ (O5 …O4^ⅲ 0.281 4(4) nm), O5—H5Y…O3^ⅳ (O5…O3^ⅳ 0.275 5(3) nm), O6—H6X…O1^ⅱ (O6…O1^ⅱ 0.284 0(3) nm), O6—H6Y…O2^ⅴ (O6…O2^ⅴ 0.275 1(3) nm). The mononuclear [Ni(HMPCA)₂(2, 2′-bpy)] components and the lattice water molecules are interlinked via the above interactions, resulting in the formation of a 1D chain (Fig. 2c). As shown in Fig. 2d, there are two intermolecular π … π interactions (Cg1…Cg2^ⅸ 0.388 6(2) nm, Cg2…Cg1^ⅹ 0.388 6(2) nm; Symmetry codes: ^ⅸx, 1/2-y, 1/2+z; ^ⅹx, 1/2-y, 1/2+z) in 2. Cg1 and Cg2 refer to the ring centroids of the pyridyl rings (Cg1: N5—C11—C12—C13—C14—C15 and Cg2: N6—C16—C17—C18—C19—C20) of 2, 2′ -bpy ligands. The dihedral angle between the pyridyl rings Cg1 and Cg2^ⅸ is 11.1°. By the function of these π …π interactions, the adjacent 1D chains are linked to form a 3D supramolecular architecture (Fig. 2e). Finally, the weak C—H… O hydrogen bonds between carbon atoms (C1, C12 and C17) from the HMPCA^- anion/2, 2′-bpy ligands and carboxylate oxygen atoms (O2 and O4) along with lattice water molecule (O5), further stabilize the 3D structure.

  2.5   PXRD and thermal analysis

  In order to check the phase purity of 1 and 2, the PXRD patterns were recorded at room temperature. As shown in Fig. S1, the experimental PXRD pattern for each complex correlated well with its simulated one generated from single-crystal X-ray diffraction data, confirming the phase purity of the bulk materials of 1 and 2.

  TGA were carried out in the interest of studying the thermal stability of two complexes. Under nitrogen atmosphere, the experiment was carried out from ambient temperature up to 800 ℃ with the heating rate of 10 ℃ ·min^-1. For 1, the first weight loss of 10.26% between 93 and 130 ℃ is attributed to the loss of two coordinated water molecules (Calcd. 10.56%) (Fig.S2). The second weight loss stage between 400 and 618 ℃ corresponds to the loss of two HMPCA^- ligands. The pyrolysis product was MnO₂ (Calcd. 25.48%; Obs. 25. 02%). For 2, the first weight loss of 7.23%, which occurred from 49 to 121 ℃, corresponds to the release of two lattice water molecules (Calcd. 7.18%). Above 300 ℃, the remaining material was gradually decomposed, and the pyrolysis product was NiO (Calcd. 15. 30%; Obs. 14.74%).

  2.6   Electrochemical property

  The electrochemical properties of 1 and 2 were investigated using a three-electrode electrochemical cell. The Ni foam coated with 1 and 2 were used as the working electrode, which was fabricated following the literature methods^[33-34]. The platinum foil and a saturated calomel electrode (SCE) were used as the counter and reference electrodes, respectively. The electrochemical measurements were carried out in a 2 mol·L^-1 KOH aqueous electrolyte at room temperature. CV curves of complexes 1 and 2 are shown in Fig. 3. During scanning from 0.05~0.3 V at a rate of 20 mV·s^-1, the CV curves only had an oxidation-reduction peak, which corresponds to M(Ⅱ)/M(Ⅲ) (M=Mn and Ni) redox process. For 1, E_pa=0.28 V, E_pc=0.14 V, ΔE=0.14 V; for 2, E_pa=0.26 V, E_pc=0.15 V, ΔE=0.11 V. The results show that electron transfer of M(Ⅱ) between M(Ⅲ) in electrolysis is quasi-reversible process.

  Figure 3

  

  Figure 3.  CV curves of 1 and 2 electrodes in 2 mol·L^-1 KOH aqueous

  下载: 全尺寸图片 幻灯片

  2.7   Luminescent properties

  The solid-state luminescent properties of free H₂MPCA ligand and complexes 1 and 2 were investigated at room temperature. As shown in Fig. 4, H₂MPCA and two complexes exhibit blue fluorescence with emission maximal at 441, 440 and 440 nm upon excitation at 331 nm, respectively. These emissions may be assigned to the intraligand (π-π*) transfer. Meanwhile, it is clear that complexes 1 and 2 exhibit weaker emissions compared with the free H₂MPCA ligand, and this kind of quenching phenomenon should be related to the ligand-field transitions (d-d)^[35-36].

  Figure 4

  

  Figure 4.  Solid-state emission spectra for complexes 1, 2 and ligand H₂MPCA at room temperature

  下载: 全尺寸图片 幻灯片

  3.   Conclusions

  We have synthesized two new complexes, [Mn(HMPCA) ₂(H₂O)₂] (1) and [Ni(HMPCA)₂(2, 2′-bpy)]·2H₂O (2), via general solution and hydrothermally synthetic methods, respectively. In the mononuclear struc-tures of 1 and 2, the HMPCA^- groups adopt a N, O-chelating coordination mode. In the function of intermolecular N—H…O and O—H…O hydrogen bonds, the independent components in 1 and 2 are extended to a porous 3D supramolecular structure with 1D nanotube structure (1) and a 1D chainlike structure (2). The 1D chains in 2 are further connected by the intermolecular π…π interactions to form a 3D supramolecular architecture. In addition, electrochemical properties of 1 and 2 show that electron transfer of M(Ⅱ) between M(Ⅲ) (M=Mn and Ni) in electrolysis is quasi -reversible process. Two complexes displayed blue fluorescence in the solid state at room temperature.

  Supporting information is available at http://www.wjhxxb.cn

  
  
• 1. [1]

     Guo J, Bae J, Fang Z W, Li P P, Zhao F, Yu G H. Chem. Rev. , 2020, 120: 7642-7707 doi: 10.1021/acs.chemrev.0c00345

  2. [2]

     Xia D Y, Wang P, Ji X F, Khashab N M, Sessler J L, Huang F H. Chem. Rev. , 2020, 120: 6070-6123 doi: 10.1021/acs.chemrev.9b00839

  3. [3]

     Xiu M M, Kang Q, Tao M L, Chen Y, Wang Y. J. Mater. Chem. C, 2018, 6: 5926-5936

  4. [4]

     Xue J Y, Li C, Li F L, Gu H W, Braunstein P, Lang J P. Nanoscale, 2020, 12: 4816-4825 doi: 10.1039/C9NR10109H

  5. [5]

     Zhang M J, Li H X, Young D J, Li HY, Lang J P. Org. Biomol. Chem. , 2019, 17: 3567-3574 doi: 10.1039/C9OB00418A

  6. [6]

     Wang B, Lv X L, Feng D W, Xie L H, Zhang J, Li M, Xie Y B, Li J R, Zhou H C. J. Am. Chem. Soc. , 2019, 138: 6204-6216

  7. [7]

     Li J, Chen S, Jiang L Y, Wu D P, Li Y S. Inorg. Chem. , 2019, 58: 5410-5413 doi: 10.1021/acs.inorgchem.9b00550

  8. [8]

     Rogge M J, Bavykina A, Hajek J, Garcia H, Olivos-Suarez A I, Sepúlveda-Escribano A, Vimont A, Clet G, Bazin P, Kapteijn F, Da-turi M, Ramos-Fernandez E V, Xamena F X L, Speybroeck V V, Gascon J. Chem. Soc. Rev. , 2017, 46: 3134-3184

  9. [9]

     Noh T H, Jung O S. Acc. Chem. Res. , 2016, 49: 1835-1843 doi: 10.1021/acs.accounts.6b00291

  10. [10]

      Liu j, Wei Y, Li P, Zhao Y L, Zou R. J. Phys. Chem. C, 2017, 121: 13249-13255 doi: 10.1021/acs.jpcc.7b04465

  11. [11]

      Tu B B, Pang Q Q, Ning E, Yan W Q, Qi Y, Wu D F, Li Q W. J. Am. Chem. Soc. , 2015, 137: 13456-13459 doi: 10.1021/jacs.5b07687

  12. [12]

      Jacobsen J, Reinsch H, Stock N. Inorg. Chem. , 2018, 57: 12820-12826 doi: 10.1021/acs.inorgchem.8b02019

  13. [13]

      Kongpatpanich K, Horike S, Sugimoto M, Fukushima T, Umeyama D, Tsutsumi Y, Kitagawa S. Inorg. Chem. , 2014, 53: 9870-9875 doi: 10.1021/ic501459m

  14. [14]

      Cheng M L, Qin M N, Sun L, Liu L, Liu Q, Tang X Y. Dalton. Trans. , 2020, 49: 7758-7765 doi: 10.1039/C9DT04927D

  15. [15]

      Liu J, Cheng M L, Yu L L, Chen S C, Shao Y L, Liu Q, Zhai C W, Yin F X. RSC Adv. , 2016, 6: 52040-52047 doi: 10.1039/C6RA10989F

  16. [16]

      Cheng M L, Bao J T, Wu Y J, Yang B X, Wang Q H, Sun L, Liu Q. ChemistrySelect, 2018, 3: 4811-4817 doi: 10.1002/slct.201800258

  17. [17]

      Chen S, Cheng M L, Ren Y H, Tang Y Z P, Liu X X, Zhai C W, Liu Q. Z. Anorg. Allg. Chem. , 2015, 641: 610-616 doi: 10.1002/zaac.201400484

  18. [18]

      Cheng M L, Wang Q H, Bao J T, Wu Y J, Sun L, Yang B X, Liu Q. New J. Chem. , 2017, 41: 5151-5160 doi: 10.1039/C7NJ00835J

  19. [19]

      Cheng M L, Sun L, Han W, Wang S, Liu Q, Sun X Q, Xi H T. New J. Chem. , 2016, 40: 10504-10511 doi: 10.1039/C6NJ02338J

  20. [20]

      An C X, Lu Y C, Shang Z F, Zhang Z H. Inorg. Chim. Acta, 2008, 361: 2721-2730 doi: 10.1016/j.ica.2008.01.043

  21. [21]

      韩伟, 程美令, 刘琦, 王利东, 吴玉娟. 无机化学学报, 2012, 28(9): 1997-2004 https://cdmd.cnki.com.cn/Article/CDMD-10542-1014243224.htmHAN W, CHENG M L, LIU Q, WANG L D, WU Y J. Chinese J. Inorg. Chem. , 2012, 28: 1997-2004 https://cdmd.cnki.com.cn/Article/CDMD-10542-1014243224.htm

  22. [22]

      Hu F L, Yin X H, Mi Y, Zhang J L, Zhuang Y, Dai X Z. Inorg. Chem. Commun. , 2009, 12: 628-631 doi: 10.1016/j.inoche.2009.05.007

  23. [23]

      Hu F L, Yin X H, Mi Y, Zhuang Y, Zhang S S, Huang Z J, Wang J. J. Coord. Chem. , 2009, 62: 3613-3620 doi: 10.1080/00958970903156566

  24. [24]

      唐李志鹏, 杨明炜, 程美令, 刘琦. 无机化学学报, 2015, 31(3): 603-610 https://www.cnki.com.cn/Article/CJFDTOTAL-XDYC201502002.htmTANG L Z P, YANG M W, CHENG M L, LIU Q. Chinese J. Inorg. Chem. , 2015, 31(3): 603-610 https://www.cnki.com.cn/Article/CJFDTOTAL-XDYC201502002.htm

  25. [25]

      包金婷, 程美令, 刘琦, 韩伟, 纪云洲, 翟长伟, 洪健, 孙小强. 无机化学学报, 2013, 29(7): 1504-1512 https://www.cnki.com.cn/Article/CJFDTOTAL-DLXB201501010.htmBAO J T, CHENG M L, LIU Q, HAN W, JI Y Z, ZHAI C W, HONG J, SUN X Q. Chinese J. Inorg. Chem. , 2013, 29(7): 1504-1512 https://www.cnki.com.cn/Article/CJFDTOTAL-DLXB201501010.htm

  26. [26]

      任艳秋, 韩伟, 程美令, 杨勇, 刘琦. 无机化学学报, 2014, 30(11): 2635-2644 https://cdmd.cnki.com.cn/Article/CDMD-10110-1017167161.htmREN Y Q, HAN W, CHENG M L, YANG Y, LIU Q. Chinese J. Inorg. Chem. , 2014, 30(11): 2635-2644 https://cdmd.cnki.com.cn/Article/CDMD-10110-1017167161.htm

  27. [27]

      翟长伟, 程美令, 韩伟, 刘琦. 无机化学学报, 2015, 31(7): 1409-1416 https://www.cnki.com.cn/Article/CJFDTOTAL-XDYC201502002.htmZHAI C W, CHENG M L, HAN W, LIU Q. Chinese J. Inorg. Chem. , 2015, 31(7): 1409-1416 https://www.cnki.com.cn/Article/CJFDTOTAL-XDYC201502002.htm

  28. [28]

      Cheng M L, Han W, Liu Q, Bao J T, Li Z F, Chen L T, Sun X Q, Xi H T. J. Coord. Chem. , 2014, 67: 215-226 doi: 10.1080/00958972.2013.879983

  29. [29]

      Yuan D Y, Wang J, Qian X, Li B L, Li Y. J. Mol. Struct. , 2011, 998: 233-239 doi: 10.1016/j.molstruc.2011.05.038

  30. [30]

      Qin S N, Hu J R, Chen Z L, Liang F P. J. Coord. Chem. , 2011, 64: 3718-3728 doi: 10.1080/00958972.2011.630072

  31. [31]

      Crane J D, Fox O D, Sinn E. J. Chem. Soc. Dalton. Trans. , 1999, 9: 1461-1466

  32. [32]

      Sheldrick G M. SHELXT-2013, University of Göttingen, Germany, 2013.

  33. [33]

      Song Y D, Yu L L, Gao Y R, Shi C D, Cheng M L, Wang X M, Liu H J, Liu Q. Inorg. Chem. , 2017, 56: 11603-11609 doi: 10.1021/acs.inorgchem.7b01441

  34. [34]

      Cheng M L, Liu L, Sun L, Tao F, Qin M N, Liu Q, Tang X Y. J. Chem. Crystallogr. , 2021, 51: 265-272 doi: 10.1007/s10870-020-00854-1

  35. [35]

      Pan Z R, Song Y, Jiao Y, Fang Z J, Li Y Z, Zheng H G. Inorg. Chem. , 2008, 47: 5162-5168 doi: 10.1021/ic702473y

  36. [36]

      Zhao J, Wang X L, Shi X, Yang Q H, Li C. Inorg. Chem. , 2011, 50: 3198-3205 doi: 10.1021/ic101112b

• 

  Figure 1  (a) Molecular structure of 1 with thermal ellipsoid at 30% probability level, where the hydrogen atoms attached to C atoms are omitted for clarity; (b) Two types of intermolecular hydrogen bonding interactions in 1, where only hydrogen atoms involved in the hydrogen bonds are shown; (c) 1D nanotube structure in 1 viewed along c axis; (d) Perspective view of 3D supramolecular structure with 1D channels of 1

  Hydrogen bonds are indicated by dash lines; Symmetry codes: ^ⅰ 1/3+y, -1/3+x, 1/6-z; ^ⅱ 2/3-x+y, 1/3+y, -1/6+z; ^ⅲ 2/3-x, 1/3-y, 1/3-z; ^ⅳ 2/3+y, 1/3-x+y, 1/3-z

  下载: 全尺寸图片 幻灯片
  

  Figure 2  (a) Coordination environment of Ni(Ⅱ) ion in 2 with thermal ellipsoid at 30% probability level, where lattice water molecules and the hydrogen atoms attached to C atoms are omitted for charity; (b) Intermolecular hydrogen bonding interactions in 2, where the 2, 2′-bpy ligand coordinated to Ni1 is omitted for clarity; (c) 1D chain structure constructed by O—H…O and N—H…O hydrogen bonds in 2; (d) π…π interactions between the pyridyl groups of the 2, 2′-bpy ligands; (e) 3D supramolecular structure in 2 constructed by hydrogen bonds and π…π interactions

  Only hydrogen atoms involved in the hydrogen bonds are shown; Hydrogen bonds and π…π interactions are indicated by dashed lines; Symmetry codes: ^ⅰ-1+x, -1+y, z; ^ⅱ 1-x, -y, 1-z; ^ⅵ x, y, 1+z; ^ix x, 1/2-y, 1/2+z; ^ⅹ x, 1/2-y, 1/2+z

  下载: 全尺寸图片 幻灯片
  

  Figure 3  CV curves of 1 and 2 electrodes in 2 mol·L^-1 KOH aqueous

  下载: 全尺寸图片 幻灯片
  

  Figure 4  Solid-state emission spectra for complexes 1, 2 and ligand H₂MPCA at room temperature

  下载: 全尺寸图片 幻灯片

  Table 1.  Crystallographic data and refinement parameters for complexes 1 and 2

  Complex	1	2
  Empirical formula	C10H14O6Mn	C20H22O6Ni
  Formula weight	341.19	501.14
  Crystal size/mm	0.24×0.22×0.20	0.26×0.24×0.24
  Crystal system	Trigonal	Monoclicnic
  Space group	R3c	P21/c
  a/nm	1.512 6(5)	1.667 3(3)
  b/nm	1.512 6(5)	1.519 7(3)
  c/nm	3.154 2(9)	0.911 0(2)
  β/(°)		104.99
  V/nm3	6.250(5)	2.229 7(8)
  Z	18	4
  Dc/(g·cm-3)	1.632	1.493
  F(000)	3 150	1 040
  μ(Mo Kα) /mm-1	0.984	0.92
  Independent reflection (Rint)	1 225 (0.117 3)	5 126 (0.074 1)
  Data, restraint, parameter	1 225, 2, 104	5 126, 4, 300
  Goodness-of-fit on F2	1.169	0.941
  R1, wR2 [I > 2σ(I)]	0.041 7, 0.105 8	0.045 2, 0.078 9
  R1, wR2 (all data)	0.053 4, 0.110 6	0.103 5, 0.096 0
  Largest diff. peak and hole/(e·nm-3)	632 and -1 663	355 and -353

  下载: 导出CSV
•