CN102040632B - Metal coordination polymer and its preparation method and application - Google Patents

Abstract

The invention discloses a metal coordination polymer as well as its preparation method and application. The polymer has a general structural formula as shown in formula I. In the general structural formula of formula I, R is tetrabutylammonium ion, tetradecyltrimethylammonium ion, Na or Ni, and M is Zn, Ni, Cu , Au, Pd or Pt. The preparation method comprises the following steps: first reacting sodium methylate and 1,3,4,6-tetrathiadicyclopentene-2,5-dione in an organic solvent under an inert atmosphere; then adding chlorine hexahydrate The organic solution of nickel chloride continues to react, and then the organic solution of ammonium salt is added to continue the reaction; after drying, iodine or air oxidation, the product is obtained. The polymer has an electrical conductivity of 12.4S/cm at 320K, a seebeck coefficient of 170μV/K, a thermal conductivity of 0.3W/m/K, and a thermoelectric figure of merit ZT of 0.04. It is an excellent p-type organic thermoelectric conversion Material.

Description

Metal coordination polymer and its preparation method and application

technical field

The invention relates to an organic thermoelectric material, in particular to a metal coordination polymer and its preparation method and application.

Background technique

In 1834, French physicist J.C.A.Peltier discovered that thermoelectric materials can provide conversion between electrical energy and thermal energy; in 1923, Seebeck reported that temperature differences can generate electromotive force (Seebeck effect) without Moving mechanical parts, where electric potentials can generate temperature differences (Peltier effect), have received much attention. The thermoelectric effect itself is reversible, either from electrical energy to thermal energy or from thermal energy to electrical energy. Although the scientific community at that time attached great importance to the discoveries of Peltier and Seebeck, the discoveries were not quickly transformed into applications. This is because the thermoelectric conversion efficiency of metals is generally very low. Until the 1950s, some semiconductor materials with excellent thermoelectric conversion properties were discovered, and the research on thermoelectric technology (thermoelectric refrigeration and thermoelectric power generation) became a hot topic.

Compared with inorganic thermoelectric materials, organic thermoelectric materials have the characteristics of low cost, high seebeck coefficient, and low thermal conductivity. Inorganic semiconductor materials have been studied more, compared to organic thermoelectric materials, the research is still relatively small. In recent years, organic thermoelectric materials have received great attention and are one of the key development directions of thermoelectric materials (Mildred S. Dresselhaus, Gang Chen, Adv. Mater., 2007, 19, 1043-1053; Yan H, Ohta T, Toshima N. Macromol. Mater. Eng., 2001, 286(3), 139-142; S.B. Riffat, X. Ma, Applied Thermal Engineering, 2003, 3, 913-935).

At present, the molecular materials with good performance as organic thermoelectric materials mainly include the following types: polyaniline, carbon tube doped materials, etc. However, these materials generally have problems such as low seebeck coefficient and low conductivity. Therefore, the design of organic thermoelectric materials with excellent comprehensive performance is still a research topic.

Contents of the invention

The object of the present invention is to provide a metal coordination polymer and its preparation method and application.

The metal coordination polymer provided by the present invention has a general structural formula as shown in formula I,

In the general structural formula of formula I, R is tetrabutylammonium ion, tetradecyltrimethylammonium ion, Na, Cu or Ni, M is Zn, Ni, Cu, Au, Pd or Pt, m:n=1 -2:1-6, m:n can specifically be 1:1-4, 1-1.3:1-4, 1:1, 2:1-6, 2:1, 1.8:1-6, 1.8:1 -4, 1.8:1, 1:1-5, 1:5 or 1:4-5; m can be specifically 1, 1.3, 1.8, 2 or 17.67, and n can be specifically 1, 4, 5 or 10; x =0-3, specifically any value between 0-2, 1-2 or 1 or 2; y=0-2, specifically any value between 0-1 or 1; z=0- 5. Specifically, it can be any value between 0-1, 0-2, 0-1.86, 0-4.3, 1-4.3, 2-4.3 or 1-4.5 or 1, 2 or 4.3 or 4.5.

The method for preparing the above-mentioned metal coordination polymer provided by the present invention comprises the following steps:

1) Under an inert atmosphere, react sodium methoxide with 1,3,4,6-tetrathiadicyclopentene-2,5-dione in an organic solvent;

2) After the reaction in step 1) is completed, the organic solution of the metal salt is added to the reaction system in step 1) to continue the reaction;

3) After the reaction of the step 2) is completed, the organic solution of the ammonium salt is added to the reaction system of the step 2) to continue the reaction;

4) The reaction product obtained in step 3) is dried, dispersed in methanol, and oxidized with iodine or air to obtain the metal coordination polymer provided by the present invention.

In step 1) of the method, the inert atmosphere is a nitrogen atmosphere, and the mass ratio of the sodium methoxide to the 1,3,4,6-tetrathiadicyclopentene-2,5-dione is 20-33 : 20-21, preferably 28: 20; the concentration of the sodium methylate in the organic solvent is 11-15mg/mL, preferably 12mg/mL; the organic solvent is methanol; the reaction temperature is 10-30°C; The time is 0.5-2 hours, preferably 1 hour;

In the step 2), the metal salt is selected from at least one of nickel chloride hexahydrate, copper chloride, palladium chloride and platinum chloride; in the organic solution of the metal salt, the solvent is methanol; the The concentration of the methanol solution of the metal salt is 12-20mg/mL, preferably 15mg/mL; the reaction temperature is 10-70°C, preferably 25°C; the reaction time is 0.5-1 hour, preferably 0.5 hour;

In the step 3), the ammonium salt is tetrabutylammonium bromide, tetradecyltrimethylammonium bromide or tetramethylammonium bromide, as shown in formula II successively; the ammonium salt and the The mass ratio of the metal salt is 31-35:9-11, preferably 32:10; the reaction temperature is 10-30°C, preferably 25°C; the reaction time is 0.5-3 hours, preferably 1 hour;

In the step 4), the dosage ratio of the reaction product to methanol is 4-8mg: 1ml, preferably 6mg: 1ml; the mass ratio of the product to iodine is 10-15: 5-8. The oxidation temperature is 10-30°C, preferably 25°C; the iodine oxidation time is 2-5 hours, preferably 3 hours; the air oxidation time is 7-13 days, preferably 12 days.

In addition, the application of the above-mentioned metal coordination polymer provided by the present invention in the preparation of organic thermoelectric materials also belongs to the protection scope of the present invention.

The metal coordination polymer based on ethylene tetrathiolate prepared by the present invention has excellent thermoelectric properties, high seebeck coefficient and very low thermal conductivity, and the electrical conductivity is moderate, which can be as high as 12.4S/ at 320K cm, the seebeck coefficient can reach 170μV/K, the thermal conductivity is 0.3W/m/K, the thermoelectric figure of merit ZT can reach 0.04, and it is stable in air. It is an excellent p-type organic thermoelectric conversion material. The method for preparing the above-mentioned polymer provided by the present invention is wet synthesis, has short process flow and low cost, and has broad application prospects in the field of organic thermoelectric materials.

Description of drawings

Fig. 1 is the conductance curve with temperature of the metal coordination polymer prepared in Example 1;

Fig. 2 is the variation curve of Seebeck coefficient with temperature of the metal coordination polymer prepared in Example 1.

3 is a photoelectron spectroscopy (XPS) spectrum of the metal coordination polymer prepared in Example 1.

Fig. 4 is the photoelectron spectroscopy (XPS) spectrogram of the metal coordination polymer prepared in Example 2.

5 is a photoelectron spectroscopy (XPS) spectrum of the metal coordination polymer prepared in Example 3.

6 is a photoelectron spectroscopy (XPS) spectrum of the metal coordination polymer prepared in Example 4.

Fig. 7 is the conductance curve of the metal coordination polymer prepared in Example 2 as a function of temperature;

Fig. 8 is the variation curve of the seebeck coefficient of the metal coordination polymer prepared in Example 2 with temperature;

Fig. 9 is the conductance curve of the metal coordination polymer prepared in Example 4 as a function of temperature;

FIG. 10 is a curve of the seebeck coefficient of the metal coordination polymer prepared in Example 4 as a function of temperature.

Detailed ways

The present invention will be further described below in conjunction with specific examples, but the present invention is not limited to the following examples.

The method for preparing the metal coordination polymer based on ethylene tetrathiolate provided by the invention is to use 1,3,4,6-tetrathiadicyclopentene-2,5-dione as raw material, through alkali and Metal salts generate metal complexes, and then generate charge transfer complexes through ammonium salts or other metal ions, and oxidize them to obtain the final product. The synthesis route is as follows:

The material prepared by the present invention can be tested for thermoelectric performance by the following method: testing the thermoelectric performance of the product. The sample is pressed into tablets to obtain a regular cuboid, which is measured with a four-electrode method, and the resistance at different temperatures is obtained by measuring with a low-temperature electrical and magnetic performance system. The sample is also pressed into tablets, and the Seebeck coefficient is measured with the SeebeckMeasurement System (SB-100). In addition, the thermal conductivity of the samples was measured.

Embodiment 1, the metal coordination polymer based on ethylene tetrathiolate shown in the preparation formula a

Put 1,3,4,6-tetrathiadicyclopentene-2,5-dione (170mg) into a 50ml three-necked flask, add 20ml of nitrogen-protected methanol solution with a concentration of 12mg/mL sodium methoxide, room temperature Stir under nitrogen protection for 1 hour. Inject 15 ml of methanol solution of nickel chloride hexahydrate with a concentration of 13 mg/mL into the above solution, and stir at room temperature for half an hour. Add 20 mL of tetradecyltrimethylammonium bromide methanol solution with a concentration of 27 mg/mL, and stir at room temperature for half an hour. The solid was obtained by suction filtration and washed with methanol and water. Vacuum dry overnight. The obtained solid was dissolved in 10 mL of methanol at a concentration of 4 mg/mL, 20 mg of iodine was added, and oxidized at room temperature for 3 hours to obtain 189 mg of a metal coordination polymer based on ethylene tetrathiolate represented by formula a, with a yield of 42.7%.

The photoelectron spectroscopy (XPS) spectrogram is shown in Figure 3, as can be seen from the figure, Ni, I, N, S, C exist in the compound (O is free oxygen in the air), and it can be known from its binding energy data that the Ni valence is +2 valence, and should be bonded to S, S has two different valence states, and I is -1 valence.

Obtain the content of C, H, N by organic elemental analysis, obtain the content of Ni by inductively coupled plasma atomic emission spectrometer (ICP-OES) instrument analysis as follows:

Elemental analysis: C: 20.22, H: 2.45, N: 0.87, Ni: 16.63

Theoretical values: C: 20.29, H: 2.79, N: 1.02, Ni: 16.47

Carry out the detection of thermoelectric performance to the metal coordination polymer based on ethylene tetrathiolate shown in formula a:

The sample was pressed into tablets to obtain a regular cuboid, which was measured with a four-electrode method and measured with a low-temperature electrical and magnetic performance system to obtain resistance at different temperatures. The conductivity was 0.45S/cm at 322.5K. Similarly, the metal coordination polymer based on ethylene tetrathiolate shown in formula a was pressed into tablets, and the seebeck coefficient was measured with Seebeck Measurement System (SB-100). It was found that the seebeck coefficient could be as high as 250μV/K at 322.5K, as shown in the figure 2. In addition, the thermal conductivity of the metal coordination polymer based on ethylene tetrathiolate represented by formula a was measured, and its thermal conductivity was 0.3 W/K/m at 322.5K. It can be obtained that its thermoelectric figure of merit reaches ZT=0.003 at 322.5K, as shown in Figure 1.

Embodiment 2, the metal coordination polymer based on ethylene tetrathiolate shown in synthetic formula b

Put 1,3,4,6-tetrathiadicyclopentene-2,5-dione (261mg) into a 50ml three-necked flask, add 20ml of methanol solution of sodium methoxide with a concentration of 15mg/mL under nitrogen protection, Stir at room temperature for 1 hour under nitrogen protection. Inject 15 ml of a methanol solution of nickel chloride hexahydrate with a concentration of 20 mg/mL into the above solution, and stir at room temperature for 1 hour. The solid was obtained by suction filtration and washed with methanol and water. Vacuum dry overnight. The obtained solid was dissolved in 10 mL of methanol at a concentration of 6 mg/mL, and oxidized in air at room temperature for 13 days to obtain 200 mg of an ethylene tetrathiolate-based metal coordination polymer represented by formula b, with a yield of 78.0%.

Fig. 4 is the photoelectron energy spectrogram of this compound, as can be seen from the figure, Ni, Na, S, C exist in the compound (O is free oxygen in the air, N is the test pollution), and by its binding energy data, it can be known that the Ni valence is +2 valence, and should be bonded to S, which has two different valence states.

Obtain the content of C by organic element analysis, obtain Ni by inductively coupled plasma atomic emission spectrometry (ICP-OES) instrument analysis, the content of Na is as follows:

Elemental analysis: C 9.40, Na 16.09, Ni 25.56

Theoretical value: C 9.33, Na 15.78, Ni 25.08

Carry out the detection of thermoelectric performance to the metal coordination polymer based on ethylene tetrathiolate shown in formula b:

The sample was pressed into tablets to obtain a regular cuboid, which was measured with a four-electrode method and measured with a low-temperature electrical and magnetic performance system to obtain resistance at different temperatures. The conductivity was as high as 12.4S/cm at 320K. Similarly, the metal coordination polymer based on ethylene tetrathiolate shown in formula b was pressed into tablets, and the seebeck coefficient was measured with Seebeck Measurement System (SB-100). It was found that the seebeck coefficient could be as high as 106 μV/K at 320K, as Figure 8 shows. In addition, the thermal conductivity of the metal coordination polymer based on ethylene tetrathiolate shown in formula b was also measured. The thermal conductivity is 0.3W/K/m, and the thermoelectric figure of merit ZT=0.015, as shown in the figure 7.

Embodiment 3,

Metal coordination polymer based on ethylene tetrathiolate shown in synthetic formula c

Put 1,3,4,6-tetrathiadicyclopentene-2,5-dione (175mg) into a 50ml three-necked flask, add 20ml of methanol solution of sodium methoxide with a concentration of 12mg/mL under nitrogen protection, Stir at room temperature for 1 hour under nitrogen protection. Inject 15ml of anhydrous copper chloride methanol solution with a concentration of 15mg/mL into the above solution, heat at 70°C and stir under reflux for 1 hour. The solid was obtained by suction filtration and washed with methanol, water and hydrochloric acid. Vacuum dry overnight. 181 mg of metal coordination polymer based on ethylene tetrathiolate represented by formula c was obtained with a yield of 65.1%.

Figure 5 is the photoelectron energy spectrum of the compound. It can be seen from the figure that Cu, O, S, and C exist in the compound, and from its binding energy data, it can be seen that the valence of Cu is +2, and it should be bonded to S. There are two different valence states.

Ni, I, N, S, C exist in the compound (O is free oxygen in the air), and its binding energy data shows that the Ni valence is +2, and it should be bonded to S, which has two different valences state, I is -1 valence.

The content of C and H was obtained by organic element analysis, and the content of Cu obtained by inductively coupled plasma atomic emission spectrometry (ICP-OES) analysis was as follows:

Elemental analysis: C 7.15, H 1.17, Cu 38.03

Theoretical value: C 7.25, H 1.22, Cu 38.35

Carry out the detection of thermoelectric performance to the metal coordination polymer based on ethylene tetrathiolate shown in formula c:

The sample was pressed into tablets to obtain a regular cuboid, which was measured with four electrodes and measured with a low-temperature electrical and magnetic system to obtain the resistance at different temperatures. The conductivity reached 1.2S/cm at 320K. Similarly, the metal coordination polymer based on ethylene tetrathiolate shown in formula c was pressed into tablets, and the seebeck coefficient was measured with Seebeck Measurement System (SB-100). It was found that the seebeck coefficient could reach 10μV/K at 320K. In addition, The thermal conductivity of the metal coordination polymer based on ethylene tetrathiolate represented by formula c was also measured, and the thermal conductivity was 0.3 W/K/m at 320K. The thermoelectric figure of merit ZT=1.3*10 ^-5 at 320K can be obtained.

Embodiment 4,

Metal coordination polymer based on ethylene tetrathiolate shown in synthetic formula d

Put 1,3,4,6-tetrathiadicyclopentene-2,5-dione (166mg) into a 50ml three-necked flask, add 20ml of methanol solution of sodium methoxide with a concentration of 11mg/mL under nitrogen protection, Stir at room temperature for 1 hour under nitrogen protection. Inject 15 ml of methanol solution of nickel chloride hexahydrate with a concentration of 12 mg/mL into the above solution, and stir at room temperature for 1 hour. The solid was obtained by suction filtration and washed with methanol and water. Vacuum dry overnight. The obtained solid was dissolved in 10 mL of methanol at a concentration of 8 mg/mL, 42 mg of iodine was added, and oxidized at room temperature to obtain 166 mg of a metal coordination polymer based on ethylene tetrathiolate represented by formula d, with a yield of 71.6%.

Figure 6 is the photoelectron energy spectrum of the compound. It can be seen from the figure that Ni, I, N, S, and C exist in the compound (O is free oxygen in the air), and it can be seen from the binding energy data that the Ni valence is +2 , and should be bonded with S, S has two different valence states, and I is -1 valence.

Obtain the content of C, H, N by organic element analysis, obtain the content of Ni by inductively coupled plasma atomic emission spectrometry (ICP-OES) analysis as follows:

Elemental analysis: C 20.60, H 2.30, N 1.00, Ni18.96

Theoretical value: C 20.37, H 2.37, N 0.91, Ni19.14

Carry out the detection of thermoelectric performance to the metal coordination polymer based on ethylene tetrathiolate shown in formula d:

The sample was pressed into tablets to obtain a regular cuboid, which was measured with four electrodes and measured with a low-temperature electric and magnetic system to obtain the resistance at different temperatures. The conductivity reached 0.26S/cm at 320K. Similarly, the metal coordination polymer based on ethylene tetrathiolate shown in formula d is pressed into tablets, and the seebeck coefficient is measured with Seebeck Measurement System (SB-100). It is found that the seebeck coefficient can be as high as 27μV/K at 320K, as Figure 10 shows. In addition, the thermal conductivity of the metal coordination polymer based on ethylene tetrathiolate represented by formula d was also measured. The thermal conductivity at 320K is 0.3W/K/m, and the thermoelectric figure of merit at 320K is ZT=2.0 *10 ^-5 , as shown in Figure 9.

Claims (5)

1. the metal coordinating polymer shown in formula a, formula b or formula c structure,

2. a method of preparing metal coordinating polymer described in claim 1 Chinese style a, comprises the steps:

1), under inert atmosphere, by sodium methylate and 1,3,4,6-, tetra-sulphur two cyclopentenes-2,5-diketone reacts in organic solvent;

2) described step 1) after completion of the reaction, the organic solution of metal-salt is joined to step 1) reaction system in proceed reaction;

3) described step 2) after completion of the reaction, the organic solution of ammonium salt is joined to described step 2) reaction system in proceed reaction;

4) by step 3) after the reaction product that obtains is dry, be scattered in methyl alcohol, with iodine oxidation, obtain metal coordinating polymer described in claim 1 Chinese style a;

Step 1), in, described inert atmosphere is nitrogen atmosphere, described sodium methylate and described 1,3,4, and 6-tetra-sulphur two cyclopentenes-2, the mass ratio of 5-diketone is 20-33:20-21; The concentration of described sodium methylate in described organic solvent is 11-15mg/mL; Described organic solvent is methyl alcohol;

Step 2), in, described metal-salt is selected from Nickel dichloride hexahydrate; In the organic solution of described metal-salt, solvent is methyl alcohol;

Step 3), in, described ammonium salt is Tetradecyl Trimethyl Ammonium Bromide; The mass ratio of described ammonium salt and described metal-salt is 31-35:9-11;

Described step 4), in, the amount ratio of described reaction product and methyl alcohol is 4-8mg:1mL; The mass ratio of described product and iodine is 10-15:5-8;

Described step 1), in, temperature of reaction is 10-30 ℃; Reaction times is 0.5-2 hour;

Described step 2), in, the temperature of reaction is 10-70 ℃; The time of reaction is 0.5-1 hour;

Described step 3), in, the temperature of reaction is 10-30 ℃; The time of reaction is 0.5-3 hour;

Described step 4), in, the temperature of oxidation is 10-30 ℃; The time of iodine oxidation is 2-5 hour.

3. method according to claim 2, is characterized in that: described step 1), and described sodium methylate and described 1,3,4,6-tetra-sulphur two cyclopentenes-2, the mass ratio of 5-diketone is 28:20; The concentration of described sodium methylate in described organic solvent is 12mg/mL;

Described step 2), in, the concentration of the methanol solution of described metal-salt is 13mg/mL;

Described step 3), in, the mass ratio of described ammonium salt and described metal-salt is 32:10;

Described step 4), in, the amount ratio of described reaction product and methyl alcohol is 6mg:1mL.

4. method according to claim 2, is characterized in that: described step 1), temperature of reaction is 25 ℃; Reaction times is 1 hour;

Described step 2), in, the temperature of reaction is 25 ℃; The time of reaction is 0.5 hour;

Described step 3), in, the temperature of reaction is 25 ℃; The time of reaction is 1 hour;

Described step 4), in, the temperature of oxidation is 25 ℃; The time of iodine oxidation is 3 hours.

5. the application of metal coordinating polymer in the organic thermoelectric material of preparation described in claim 1.

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