Metal organic framework compound and synthesis method thereof

Abstract

The invention relates to the field of materials, in particular to a metal organic framework compound and a synthesis method thereof.The metal organic framework compound {[Co2 (ttc) 2 (H2O)] 2DMF4H2O} n is obtained by reacting 3, 4-bis-[1, 2, 4] triazole-1-methyl-thieno [2, 3-b] thiophene-2, 5-dicarboxylic acid (H2ttc) containing two triazole groups and a thiophene carboxylic acid derivative with CoCl2. 6H2O through a low-temperature solvothermal method, crystal structure data and an infrared spectrum are obtained through single crystal X-ray diffraction and IR, it is proved that a new three-dimensional MOF structure material can be successfully prepared through the synthesis method, and compared with the prior art, the synthesis method for preparing the metal organic framework compound has the advantages of being low in energy consumption, low in reaction temperature, capable of saving time, low in cost and suitable for industrial production. The pollution is low; the yield is high.

Description

Technical Field

[0001] The invention relates to the technical field of materials, and in particular to a metal organic framework compound and a synthesis method thereof. Background Art

[0002] In recent years, proton exchange membrane fuel cells have attracted more and more attention from scientific researchers due to their high energy density, high conversion efficiency and environmental protection. The core component of proton exchange membrane fuel cells is the proton exchange membrane, which directly affects the service life and energy conversion efficiency of the battery. Its main functions are manifested in two aspects. On the one hand, it not only allows the H generated by the anode to + On the other hand, it is necessary to prevent H 2 and O 2 Direct contact can avoid battery damage or even direct explosion, thus ensuring the normal operation of the battery. Currently, the most commonly used proton exchange membrane in commercial applications is perfluoroalkyl sulfonic acid membrane (Nafion), which has a proton conductivity of 10 at 60-80°C and high humidity. -2 S cm -1 -10 -1 S cm -1 Although Nafion membranes have been commercialized, their complex preparation process, high price, and ambiguous conduction mechanism have hindered their widespread application and performance improvement. In the past two decades, alternative proton conductor materials such as ceramic oxides, inorganic solid acids, organic polymers, and metal-organic frameworks have been developed.

[0003] Metal-organic frameworks (MOFs) are solid crystalline materials with one-dimensional, two-dimensional, or three-dimensional spatial structures formed by metals or metal clusters connected by organic ligands. Due to the designability and modifiability of their structures, they have a wide range of applications in catalysis, sensing, separation, adsorption, and conductivity. As a new type of conductive material, metal-organic frameworks have received increasing attention in the field of proton conduction in recent years. However, the preparation process of traditional MOFs materials is complex, with high energy consumption, high reaction temperature, high cost, and low yield. Therefore, research has found that how to prepare highly stable porous MOFs materials is currently the focus of the research and development of high-performance proton conductive materials. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the object of the present invention is to provide a metal organic framework compound and a method for synthesizing the same. The present invention selects an organic compound having a carboxylic acid group and a triazole group, 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid (H 2 ttc) as a multifunctional ligand was used to self-assemble a new three-dimensional MOF with Co(Ⅱ) ions by low-temperature solvothermal method: {[Co2 (ttc) 2 (H 2 O)]·2DMF·4H 2 O} n .

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A method for synthesizing a metal organic framework compound comprises the following steps: using an organic compound with two triazole groups and a thiophene carboxylic acid group as a multifunctional ligand, performing a solvothermal reaction at 130 to 135° C. with Co 2+ Ionic self-assembly to form metal-organic framework compounds.

[0007] The specific steps include:

[0008] (1) CoCl 2 6H 2 O and 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid are mixed, an organic solvent and a reaction solvent are added, and the mixture is stirred at room temperature;

[0009] (2) After stirring, the mixture was heated in a reaction vessel at 130-135° C., and red rod-shaped crystals were obtained after cooling.

[0010] Preferably, in step (1), the organic solvent is DMF and the reaction solvent is water.

[0011] Preferably, in step (1), CoCl 2 6H 2 The mass ratio of O and 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid is 1:1-2.

[0012] Preferably, in step (1), the volume ratio of the organic solvent to the reaction solvent is 1:1-2, and the mass volume ratio of 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid to the organic solvent is 0.003 g:2-4 mL.

[0013] Preferably, the stirring time at room temperature in step (1) is 10 to 15 minutes, and the heating reaction time in step (2) is 3 to 4 days.

[0014] Another object of the present invention is to protect a metal organic framework compound prepared by any of the above preparation methods, wherein the chemical formula of the metal organic framework compound is {[Co 2 (ttc) 2 (H 2 O)]·2DMF·4H2 O} n , where ttc 2- is the deprotonated 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid, and DMF is N,N-dimethylformamide.

[0015] Preferably, the metal organic framework compound belongs to the tetragonal system, P 4bc space group, and the asymmetric unit includes two Co 2+ , two doubly deprotonated ttc 2- , one coordinated water, two DMF and two free water molecules, all N and O atoms on the organic ligands are coordinated with the metal Co(II) ions to form a 3D network structure in space.

[0016] Preferably, the unit cell parameters are α=β=γ=90°, Z=4.

[0017] The third object of the present invention is to provide an application of a metal organic framework compound prepared by any of the above preparation methods in proton exchange membrane materials.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1. According to the preparation method of the present invention, 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid is used as an organic ligand. The triazole and carboxylic acid groups contained in the organic ligand can serve as proton sources and participate in the construction of hydrogen bond networks, which are very beneficial to proton transport. The low-temperature solvothermal method is used to react with CoCl 2 6H 2 O mixed reaction, successfully prepared the metal organic framework compound, the chemical formula of which is {[Co 2 (ttc) 2 (H 2 O)]·2DMF·4H 2 O} n The crystal structure data and infrared spectrum were obtained by single crystal X-ray diffraction and IR, respectively, which proves that the new three-dimensional MOF structure material can be successfully prepared by the synthesis method of the present invention.

[0020] 2. The space group of the metal organic framework compound of the present invention is tetragonal system, P 4bc space group, and the asymmetric unit includes two Co 2+ , two doubly deprotonated ttc 2- , one coordinated water, two DMF and two free water molecules, all N and O atoms on the organic ligands are coordinated with the metal Co(II) ions to form a beautiful 3D network structure in space.

[0021] 3. The synthetic method for preparing metal organic framework compounds of the present invention is a one-pot method, which has the advantages of low energy consumption, low reaction temperature, time saving, low cost, low pollution and high yield compared with the prior art.

[0022] 4. A large number of hydrogen bonds exist in the metal organic framework compound of the present invention, which makes a great contribution to the construction of a three-dimensional solid framework, such as Figure 2 As shown, in metal organic framework compounds, ttc 2- All N and O atoms on the ligand are coordinated with the metal Co(II) ions to form a 3D network structure in space.

[0023] 5. The nitrogen heterocyclic carboxylic acid ligands used in the present invention have a variety of coordination modes, have strong coordination effects with metals or metal ions, and can also be partially or completely deprotonated to varying degrees, thereby forming a multidimensional MOFs structure with a complex structure and stable framework. At the same time, the carboxylic acid oxygen atoms can act as both proton donors and acceptors, forming a complex hydrogen bond network with guest molecules (such as water molecules, methanol, etc.), providing a conductive path for proton transfer, so the preparation of such MOFs is particularly important. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a structural unit diagram of the metal organic framework compound of the present invention;

[0025] Figure 2 It is a three-dimensional stacking diagram of the metal organic framework compound of the present invention. DETAILED DESCRIPTION

[0026] The following is a detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings.

[0027] Reagents and instruments

[0028] All reagents used in the present invention were of analytical grade without further purification. The element contents were measured on a FLASH smart element analyzer; the element contents were measured on a Nicolet NEXUS 470-FTIR infrared spectrometer (400-4000cm -1 ) to obtain infrared spectra; the crystals were collected in a 293(2)K environment, and single crystal tests were performed on Xcalibur, Eos, and Gemini diffractometers using CuKα (λ = 1.54184). 3,4-Bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid (H 2 ttc) was purchased from commercial channels.

[0029] Example 1

[0030] A method for synthesizing a metal organic framework compound comprises the following steps:

[0031] Weigh CoCl 2 6H 2 O (0.1 mmol, 0.0030 g), 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid (H 2 ttc) (0.0030 g) was mixed, and DMF (2 mL) and H 2 O (2 mL), stirred at room temperature for 10 min, placed in a 25 mL reactor, heated at 130 ° C for 3 days, and cooled to obtain bright red rod-shaped crystals, namely the metal organic framework compound {[Co 2 (ttc) 2 (H 2 O)]·2DMF·4H 2 O} n The yield is 72% (calculated based on Co), and the elemental analysis is C 34 H 40 Co 2 N 14 O 15 S 4 Calculated: C, 36.08%; H, 3.53%; N, 17.33%. Measured: C, 35.01%; H, 2.54%; N, 16.69%. Infrared (cm -1 ,KBr): 34249(s), 1659(m), 1615(s), 1518(m), 1488(m), 1445(w), 1362(s), 1282(w), 1196(w), 1175(w), 1128(s) , 1104(w), 1055(w), 988(w), 943(w), 877(w), 801(w), 781(w), 675(w), 643(w), 612(w), 544(w), 492(w), 491(w).

[0032] Example 2

[0033] A method for synthesizing a metal organic framework compound comprises the following steps:

[0034] Weigh CoCl 2 6H 2 O (0.1 mmol, 0.0030 g), 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid (H 2 ttc) (0.0045 g) was mixed, and DMF (2 mL) and H 2O (3 mL), stirred at room temperature for 12 min, placed in a 25 mL reactor, heated at 133 ° C for 3 days, and cooled to obtain bright red rod-shaped crystals, namely the metal organic framework compound {[Co 2 (ttc) 2 (H 2 O)]·2DMF·4H 2 O} n .

[0035] Example 3

[0036] A method for synthesizing a metal organic framework compound comprises the following steps:

[0037] Weigh CoCl 2 6H 2 O (0.1 mmol, 0.0030 g), 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid (H 2 ttc) (0.0060 g) was mixed, and DMF (2 mL) and H 2 O (4 mL), stirred at room temperature for 15 min, placed in a 25 mL reactor, heated at 135 ° C for 4 days, and cooled to obtain bright red rod-shaped crystals, namely the metal organic framework compound {[Co 2 (ttc) 2 (H 2 O)]·2DMF·4H 2 O} n .

[0038] The metal organic framework compound {[Co 2 (ttc) 2 (H 2 O)]·2DMF·4H 2 O} n Characterize the structure of

[0039] 1. Determination of crystal structure

[0040] Metal-organic framework crystals of suitable size and good transparency were selected as samples, and the crystals were collected in an environment of 293(2)K. Xcalibur, Eos, and Gemini diffractometers were used to perform single crystal tests on the crystals using CuKα (λ=1.54184). The crystal structures were analyzed, optimized, and corrected using Olex2 and ShelXS ShelXL. The data listed in Tables 1, 2, and 3 are the crystallographic data of the metal-organic framework compounds prepared in Example 1 and the values ​​of key bond lengths and key bond angles, respectively.

[0041] Table 1 Crystallographic parameters of metal organic framework compounds

[0042]

[0043]

[0044] Table 2 Important bond lengths in metal organic framework compounds data

[0045] Co(1)-N(3)#1 2.163(3) Co(1)-N(6)#2 2.103(3) Co(1)-O(1) 2.067(2) Co(1)-O(2)#3 2.134(2) Co(1)-O(4)#4 2.112(2) Co(1)-O(5) 2.1467(19) N(3)-Co(1)#5 2.163(3) N(6)-Co(1)#6 2.103(3) O(2)-Co(1)#3 2.134(2) O(4)-Co(1)#7 2.112(2) O(5)-Co(1)#3 2.1467(19)

[0046] Symmetry codes: #1+Y,3 / 2-X,3 / 2-Z; #21-Y,1 / 2+X,-1 / 2+Z; #31 / 2-X,3 / 2-Y,+Z; #4-1 / 2+ X,1 / 2+Y,1-Z; #5-1 / 2+Y,1-X,1 / 2+Z; #63 / 2-Y,+X,3 / 2-Z; #71 / 2+X,-1 / 2+Y,1-Z.

[0047] Table 3 Important bond angles (deg) data of metal organic framework compounds

[0048] N(6)#1-Co(1)-N(3)#2 92.62(12) N(6)#1-Co(1)-O(2)#3 87.55(11) N(6)#1-Co(1)-O(4)#4 96.01(11) N(6)#1-Co(1)-O(5) 173.95(11) O(1)-Co(1)-N(3)#2 84.59(10) O(1)-Co(1)-N(6)#1 87.85(11) O(1)-Co(1)-O(2)#3 99.00(10) O(1)-Co(1)-O(4)#4 174.65(11) O(1)-Co(1)-O(5) 87.19(8) O(2)#3-Co(1)-N(3)#2 176.40(10) O(2)#3-Co(1)-O(5) 89.80(9) O(4)#4-Co(1)-N(3)#2 91.51(11) O(4)#4-Co(1)-O(2)#3 84.90(10) O(4)#4-Co(1)-O(5) 89.17(8) O(5)-Co(1)-N(3)#2 90.37(10) C(1)#1-N(3)-Co(1)#5 128.7(2) C(1)#2-N(3)-Co(1)#5 127.7(2) C(1)#3-N(6)-Co(1)#6 124.6(2) C14-N6-Co16 131.9(3) C(1)-O(1)-Co(1) 129.2(2) C1-O2-Co13 127.1(2) C(8)-O(4)-Co(1)#7 125.6(2) Co(1)-O(5)-Co(1)#3 116.21(15)

[0049] 2. Crystal structure description of metal-organic framework compounds

[0050] Single crystal X-ray tests show that metal organic framework compounds {[Co 2 (ttc) 2 (H 2 O)]·2DMF·4H 2 O} n It belongs to the tetragonal system, P 4bc space group, and the asymmetric unit includes two Co 2+ , two doubly deprotonated ttc 2- , one coordinated water, two DMF and two free water molecules ( Figure 1 ), Co1 belongs to [CoO 4 N 2 ] Six-coordination mode, in which O5 comes from coordinated water, O1, O2, and O4 come from three ttc 2- The carboxyl group, N3, and N6 come from two triazoles. According to Table 4, the bond length of Co-N ranges from The bond length between Co and O is In the range, the bond angle between L-Co-L (L=N, O) is between 84.59(10)-176.40(10)°.

[0051] Table 4 Main bond lengths in metal organic frameworks and bond angle (deg)

[0052] Co(1)-N(3)#1 2.163(3) Co(1)-N(6)#2 2.103(3) Co(1)-O(1) 2.067(2) Co(1)-O(2)#3 2.134(2) Co(1)-O(4)#4 2.112(2) Co(1)-O(5) 2.1467(19) N(3)-Co(1)#5 2.163(3) N(6)-Co(1)#6 2.103(3) O(2)-Co(1)#3 2.134(2) O(4)-Co(1)#7 2.112(2) O(5)-Co(1)#3 2.1467(19) N(6)#1-Co(1)-N(3)#2 92.62(12) N(6)#1-Co(1)-O(2)#3 87.55(11) N(6)#1-Co(1)-O(4)#4 96.01(11) N(6)#1-Co(1)-O(5) 173.95(11) O(1)-Co(1)-N(3)#2 84.59(10) O(1)-Co(1)-N(6)#1 87.85(11) O(1)-Co(1)-O(2)#3 99.00(10) O(1)-Co(1)-O(4)#4 174.65(11) O(1)-Co(1)-O(5) 87.19(8) O(2)#3-Co(1)-N(3)#2 176.40(10) O(2)#3-Co(1)-O(5) 89.80(9) O(4)#4-Co(1)-N(3)#2 91.51(11) O(4)#4-Co(1)-O(2)#3 84.90(10) O(4)#4-Co(1)-O(5) 89.17(8) O(5)-Co(1)-N(3)#2 90.37(10) C(1)#1-N(3)-Co(1)#5 128.7(2) C(1)#2-N(3)-Co(1)#5 127.7(2) C(1)#3-N(6)-Co(1)#6 124.6(2) C14-N6-Co16 131.9(3) C(1)-O(1)-Co(1) 129.2(2) C1-O2-Co13 127.1(2) C(8)-O(4)-Co(1)#7 125.6(2) Co(1)-O(5)-Co(1)#3 116.21(15)

[0053] Symmetry codes: #1+Y,3 / 2-X,3 / 2-Z; #21-Y,1 / 2+X,-1 / 2+Z; #31 / 2-X,3 / 2-Y,+Z; #4-1 / 2+ X,1 / 2+Y,1-Z; #5-1 / 2+Y,1-X,1 / 2+Z; #63 / 2-Y,+X,3 / 2-Z; #71 / 2+X,-1 / 2+Y,1-Z.

[0054] In summary, the present invention selects an organic compound containing two triazole groups and thiophene carboxylic acid groups, 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid (H 2 ttc) as a multifunctional ligand was used to self-assemble a new three-dimensional MOF with Co(Ⅱ) ions by low-temperature solvothermal method: {[Co 2 (ttc) 2 (H 2 O)]·2DMF·4H 2 O} n The space group of the metal organic framework compound is tetragonal, P4bc space group, and the asymmetric unit includes two Co 2+ , two doubly deprotonated ttc 2- , one coordinated water, two DMF and two free water molecules, there are a lot of hydrogen bonds in metal organic framework compounds, which have made great contributions to the construction of three-dimensional solid frameworks, such as Figure 2 As shown, in metal organic framework compounds, ttc 2- All N and O atoms on the ligand are coordinated with the metal Co(II) ions to form a 3D network structure in space. The synthesis method of the present invention is a one-pot method and has the advantages of low energy consumption, low reaction temperature, time saving, low cost, low pollution, high yield, etc. compared with the prior art.

[0055] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for synthesizing a metal organic framework compound, characterized in that: The following steps are involved: An organic compound containing two triazole groups and a thiophene carboxylic acid group was used as a multifunctional ligand and reacted with Co by solvothermal reaction at 130-135 °C. 2+ Ionic self-assembly to form metal-organic framework compounds.

2. The method for synthesizing a metal organic framework compound according to claim 1, characterized in that: The following steps are involved: (1) CoCl2·6H2O and 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid are mixed, an organic solvent and a reaction solvent are added, and the mixture is stirred at room temperature; (2) After the stirring is completed, the reaction is carried out in a reaction vessel at 130-135° C., and red rod-shaped crystals are obtained after cooling, that is, the metal organic framework compound is obtained.

3. The method for synthesizing a metal organic framework compound according to claim 2, characterized in that: In step (1), the organic solvent is DMF and the reaction solvent is water.

4. The method for synthesizing a metal organic framework compound according to claim 2, characterized in that: In step (1), the mass ratio of CoCl2·6H2O to 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid is 1:1-2.

5. The method for synthesizing a metal organic framework compound according to claim 2, characterized in that: In step (1), the volume ratio of the organic solvent to the reaction solvent is 1:1-2, and the mass volume ratio of 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid to the reaction solvent is 0.003 g:2-4 mL.

6. The method for synthesizing a metal organic framework compound according to claim 2, characterized in that: The stirring time at room temperature in step (1) is 10 to 15 minutes, and the heating reaction time in step (2) is 3 to 4 days.

7. A metal organic framework compound synthesized according to the synthesis method according to any one of claims 1 to 6, characterized in that: The chemical formula of the metal organic framework compound is {[Co2(ttc)2(H2O)]·2DMF·4H2O} n , where ttc 2- is the deprotonated 3,4-bis-[1,2,4]triazole-1-methyl-thieno[2,3-b]thiophene-2,5-dicarboxylic acid, and DMF is N,N-dimethylformamide.

8. The metal organic framework compound according to claim 7, characterized in that The metal organic framework compound belongs to the tetragonal system, P 4bc space group, and the asymmetric unit includes two Co 2+ , two doubly deprotonated ttc 2- , one coordinated water, two DMF and two free water molecules, all N and O atoms on the organic ligands are bound to Co 2+ Ionic coordination forms a 3D network structure in space.

9. The metal organic framework compound according to claim 7, characterized in that: The unit cell parameters are α=β=γ=90°, Z=4.

10. Use of the metal organic framework compound according to any one of claims 7 to 9 in proton exchange membrane materials.

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