One-dimensional chain-like energetic complex, preparation method thereof and application of crystal in catalyzing ammonium perchlorate (AP)

Abstract

The application discloses a one-dimensional chain-shaped energetic complex, a preparation method thereof and application of the energetic complex in catalyzing ammonium perchlorate (AP). The energetic complex [Mn4(TTP)2(H2O)8] is prepared by using 2,3,5,6-tetra(1H-tetrazole-5-yl)pyrazine (H4TTP) and nitrate (manganese nitrate and zinc nitrate) as raw materials through a solvothermal method n • 2H2O or [Zn4(TTP)2(H2O)8] n The energetic complex has a one-dimensional chain structure, the stability of the complex is not higher than 300 DEG C, after being mixed with AP, the complex has excellent catalytic effect and can accelerate the decomposition process, and can also provide additional energy for the system, and therefore can be used as a catalyst in propellants, and has a good application prospect in the field of propellants.

Description

Technical Field

[0001] This invention relates to the preparation of energetic materials in the field of coordination synthesis, and particularly to one-dimensional chain-like energetic coordination compounds, their preparation methods, and the application of crystal catalysis of ammonium perchlorate (AP). Background Technology

[0002] Solid propellants play an indispensable role in the military and aerospace fields as the primary energy source for missile propulsion and rocket launch. Ammonium perchlorate (AP), as the main oxidizer in composite solid propellants, directly determines the propellant's combustion performance through its thermal decomposition characteristics. However, AP has a high thermal decomposition temperature (approximately 400°C), resulting in a low burning rate and unstable combustion. Therefore, developing highly efficient energetic catalysts to reduce the AP decomposition temperature and improve the propellant's energy characteristics is particularly urgent. Summary of the Invention

[0003] The purpose of this invention is to address the problems of poor thermal stability and low energy density of catalysts in existing technologies, and to provide a one-dimensional chain-like energetic complex, its preparation method, and its application in the crystal catalysis of ammonium perchlorate (AP). This one-dimensional chain-like energetic complex possesses both high catalytic activity and high energy characteristics, and can be used as a catalyst for the thermal decomposition of ammonium perchlorate.

[0004] The technical solution adopted in this invention is as follows:

[0005] A one-dimensional chain-like energetic complex, wherein the complex is [Mn4(TTP)2(H2O)8]. n • 2H₂O or [Zn₄(TTP)₂(H₂O)₈] n The [Mn4(TTP)2(H2O)8] n The structural formula of 2H2O is shown in formula (I): [Zn4(TTP)2(H2O)8] n The structural formula is shown in formula (Ⅱ);

[0006] Formula (I);

[0007] Formula (II).

[0008] Preferably, [Mn4(TTP)2(H2O)8] n • The 2H₂O complex belongs to the monoclinic crystal system, space group C2 / m; [Zn₄(TTP)₂(H₂O)₈] n The complex belongs to the triclinic crystal system, space group P-1.

[0009] The present invention also provides a method for preparing the above-mentioned one-dimensional chain-like energetic complex, which is synthesized by a solvothermal method using 2,3,5,6-tetra(1H-tetrazol-5-yl)pyrazine and nitrate as raw materials; wherein the nitrate is manganese nitrate or zinc nitrate.

[0010] Preferably, the molar ratio of 2,3,5,6-tetra(1H-tetrazol-5-yl)pyrazine to nitrate is 1:1.

[0011] The present invention also provides the application of the above-mentioned one-dimensional chain-like energetic complex, which is used as a catalyst for the thermal decomposition of ammonium perchlorate.

[0012] Preferably, the [Mn4(TTP)2(H2O)8] n • 2H₂O shifts the high-temperature decomposition peak of ammonium perchlorate to 357.4 °C; the [Zn₄(TTP)₂(H₂O)₈] n The high-temperature decomposition peak of ammonium perchlorate was shifted to 366.1 °C.

[0013] The beneficial effects of this invention are as follows:

[0014] 1) This invention prepares a one-dimensional chain-like energetic complex [Mn4(TTP)2(H2O)8] n • 2H₂O or [Zn₄(TTP)₂(H₂O)₈] n This one-dimensional chain-like energetic complex exhibits excellent catalytic activity against ammonium perchlorate (AP), the main oxidant in propellants, and can also provide additional energy to the system, such as [Mn4(TTP)2(H2O)8] in this invention. n • 2H₂O shifts the high-temperature decomposition peak of AP to 357.4 °C, a decrease of 73.9 °C compared to pure AP; [Zn₄(TTP)₂(H₂O)₈] n The high-temperature decomposition peak of AP was shifted to 374.1 °C, a decrease of 69.2 °C compared to pure AP. Therefore, the one-dimensional chain-like energetic complex in this invention has good application prospects in the field of energetic catalysts.

[0015] 2) The preparation method of the one-dimensional chain-like energetic complex in this invention is simple and easy to carry out on a large scale for industrial production. Attached Figure Description

[0016] Figures 1-2 The products of this invention, in sequence, are [Mn4(TTP)2(H2O)8]. n • 2H₂O and [Zn₄(TTP)₂(H₂O)₈] n The minimum asymmetric unit structure diagram;

[0017] Figures 3-4The products of this invention, in sequence, are [Mn4(TTP)2(H2O)8]. n • 2H₂O and [Zn₄(TTP)₂(H₂O)₈] n Crystal structure diagram;

[0018] Figure 5 The TG-DSC curve of the product of the embodiment of the present invention;

[0019] Among them, 5(a) [Mn4(TTP)2(H2O)8] n •2H2O, 5(b) [Zn4(TTP)2(H2O)8] n ;

[0020] Figure 6 The catalytic AP curve is shown.

[0021] Figure 7 [Mn4(TTP)2(H2O)8] n • 2H₂O and [Zn₄(TTP)₂(H₂O)₈] n The catalytic AP curve;

[0022] in, Figure 7 (a) is [Mn4(TTP)2(H2O)8] n •2H₂O, 7(b) is [Zn₄(TTP)₂(H₂O)₈] n . Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0024] The structural formula of 2,3,5,6-tetra(1H-tetrazole-5-yl)pyrazine (H4TTP) in this invention is shown below:

[0025]

[0026] H4TTP was prepared according to existing technology (ACS Appl. Energy Mater., 2018, 1, 589):

[0027] (1) Synthesis of pyrazine-2,3,5,6-tetracarboxynitrile (TCP): Diaminomaleitrile (0.02 mol, 2.16 g) was dissolved in 25 mL of trifluoroacetic acid. 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (0.01 mol, 2.27 g) was added in portions at room temperature. After stirring at room temperature for 4 h, the mixture was heated to 70 °C, filtered, and washed successively with trifluoroacetic acid and water. The resulting precipitate (mainly containing pyrazine-2,3,5,6-tetracarboxynitrile, 6-aminopyrazine-2,3,5-tricarboxynitrile, and 2,3-dichloro-5,6-dicyanohydroquinone) was purified by hot filtration after boiling in benzene. The filtrate was evaporated to dryness under reduced pressure, washed with water and chloroform, and then dried under high vacuum at room temperature to give 1.20 g of the product, with a yield of 67%. IR (KBr, cm⁻¹) -1 ): 3258, 2839, 2263, 1554, 1478, 1382, 1250, 1228, 1185,1131, 1090, 792, 627, 521, 465.

[0028] (2) Synthesis of 2,3,5,6-tetra(1H-tetrazol-5-yl)pyrazine (H4TTP): 25 mL of DMSO was added to a 50 mL four-necked flask, and a mechanical stirrer was turned on and a condenser was installed. The stirring speed was set to 400 r / min. TCP solid powder (10.0 mmol, 1.8 g) and sodium azide (42.0 mmol, 2.73 g) were weighed and added to the four-necked flask in portions. The mixture was stirred continuously, followed by the addition of tetrabutylammonium bromide (TBAB) (0.6 mmol, 0.2 g). After the addition was complete, the mixture was heated to 124 °C in an oil bath and the stirring speed was kept constant for 42 h. After the reaction was completed, the reaction mixture was poured into ice, and 10 mL of 45% dilute sulfuric acid was added to adjust the pH to 3, precipitating a solid. The solid was filtered, washed with water, and dried under vacuum at 40 °C for 5 h to obtain 2.59 g of a pale yellow solid, with a yield of 74%. 13 C NMR (100 MHz, d6-DMSO) δ / ppm: 148.1, 131.8; IR (KBr, cm -1 ): 3516, 3404, 3240, 3014, 2973,2468, 1896, 1637, 1606, 1469, 1392, 1340, 1232, 1187, 1122, 1074, 989, 964,896, 838, 748, 710, 673, 576, 534, 484.

[0029] Example 1

[0030] [Mn4(TTP)2(H2O)8]n • Preparation of 2H2O: Weigh 352 mg (1 mmol) H4TTP and dissolve it in 10 mL of LDM. Take 1 mL of the mixed solution into a hydrothermal reactor, then add 5 mL of deionized water and 23 μL (0.1 mmol) of 50% Mn(NO3)2 solution. The resulting solution is a clear yellow liquid. Transfer it to the reactor, heat it to 110 °C, keep it at that temperature for 24 h, and then cool it to room temperature to obtain orange blocky crystals.

[0031] Example 2

[0032] [Zn(H4TTP)2(H2O)2] n Preparation: Weigh 352 mg (1 mmol) H4TTP and dissolve it in 10 mL DMSO. Take 1 mL of the mixed solution into a hydrothermal reactor, then add 5 mL of deionized water and 124 μL (0.1 mmol) 20% Zn(NO3)2 solution. The resulting solution is a clear yellow liquid. Transfer it to the reactor, heat it to 110 °C, keep it at that temperature for 24 h, and then cool it to room temperature to obtain yellow blocky crystals.

[0033] Performance testing

[0034] 1. The complex [Mn4(TTP)2(H2O)8] prepared in Example 1 n • 2H2O and the complex [Zn4(TTP)2(H2O)8] prepared in Example 2 n Perform single-crystal testing.

[0035] A suitable crystal was selected and placed in a Bruker D8 Venture X-ray single-crystal diffractometer for single-crystal testing at a temperature of 293 K. The crystallographic parameters are shown in Table 1, and the crystal structure diagram is shown below. Figures 1-2 As shown.

[0036] Table 1

[0037]

[0038] 2. Regarding the complex [Mn4(TTP)2(H2O)8] n • 2H₂O (prepared in Example 1) and [Zn₄(TTP)₂(H₂O)₈] n (Preparation in Example 2) Thermal stability analysis was performed. The complexes were studied using TG testing, with heating rates of 10 °C·min. -1 The atmosphere is high-purity N. 2。 The sample volume for TG determination is approximately 1 mg.

[0039] The results are as follows Figure 5 As shown, the complex [Mn4(TTP)2(H2O)8] n• 2H₂O and [Zn₄(TTP)₂(H₂O)₈] n It exhibits good thermal stability, with exothermic peaks of 292 ℃ and 297 ℃, and its thermal stability does not exceed 300 ℃.

[0040] 3. The complexes [Mn4(TTP)2(H2O)8] prepared in Examples 1 and 2 n • 2H₂O and [Zn₄(TTP)₂(H₂O)₈] n Catalytic properties were analyzed. The complex was mixed with AP at a specific mass ratio ([Mn4(TTP)2(H2O)8) n • 2H₂O, [Zn₄(TTP)₂(H₂O)₈] n Mix 10% of the sample, and place a total of 4 mg into a covered alumina crucible and mix thoroughly. Perform DTA testing in air at 10 °C·min⁻¹.

[0041] Test results are as follows Figure 7 As shown in (a) and 7(b), the complex [Mn4(TTP)2(H2O)8] exhibits good catalytic properties. n • 2H₂O shifts the high-temperature decomposition peak of AP to 357.4 °C, compared with pure AP ( Figure 6 Compared to [Zn4(TTP)2(H2O)8], the temperature decreased by 73.9 °C. n The high-temperature decomposition peak of AP was shifted to 366.1 °C, compared with pure AP ( Figure 6 The temperature decreased by 69.2 °C compared to the previous year.

[0042] In summary, the energetic complex [Mn4(TTP)2(H2O)8] prepared by this invention... n • 2H₂O (ECP-1) and [Zn₄(TTP)₂(H₂O)₈] n (ECP-2) has a good catalytic effect on ammonium perchlorate (AP), the main oxidant of propellants, and has good application prospects in the field of energetic catalysts.

[0043] The specification and drawings of this invention are intended to be illustrative rather than restrictive. Based on this invention, those skilled in the art can make substitutions and modifications to some of the technical features without creative effort, and all such modifications are within the scope of protection of this invention.

Claims

1. A one-dimensional chain-like energetic complex, characterized in that, The complex is [Mn4(TTP)2(H2O)8]. n • 2H₂O or [Zn₄(TTP)₂(H₂O)₈] n The [Mn4(TTP)2(H2O)8] n The structural formula of 2H2O is shown in formula (I): [Zn4(TTP)2(H2O)8] n The structural formula is shown in formula (Ⅱ); Formula (I); Formula (II).

2. The one-dimensional chain-like energetic complex according to claim 1, characterized in that, [Mn4(TTP)2(H2O)8] n • The 2H₂O complex belongs to the monoclinic crystal system, space group C2 / m; [Zn₄(TTP)₂(H₂O)₈] n The complex belongs to the triclinic crystal system, space group P-1.

3. The method for preparing the one-dimensional chain-like energetic complex as described in claim 1 or 2, characterized in that, It is synthesized by a solvothermal method using 2,3,5,6-tetra(1H-tetrazol-5-yl)pyrazine and nitrate as raw materials; the nitrate is manganese nitrate or zinc nitrate.

4. The preparation method according to claim 3, characterized in that, The molar ratio of the 2,3,5,6-tetra(1H-tetrazol-5-yl)pyrazine to the nitrate is 1:

1.

5. The application of the one-dimensional chain-like energetic complex as described in claim 1 or 2, characterized in that, The one-dimensional chain-like energetic complex is used as a catalyst to catalyze the thermal decomposition of ammonium perchlorate.

6. The application according to claim 5, characterized in that, The [Mn4(TTP)2(H2O)8] n • 2H₂O shifts the high-temperature decomposition peak of ammonium perchlorate to 357.4 °C; the [Zn₄(TTP)₂(H₂O)₈] n The high-temperature decomposition peak of ammonium perchlorate was shifted to 366.1 °C.

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