A controllable synthesis method of 1,4,7,10-tetraazacyclododecane pentazolate

Abstract

This invention provides a controllable synthesis method for 1,4,7,10-tetraazacyclododecanepentazole salt, belonging to the field of energetic materials technology. It includes two synthesis methods: the first is the synthesis of 1,4,7,10-tetraazacyclododecane dipentazole salt, in which 1,4,7,10-tetraazacyclododecane tetrahydrochloride is dissolved in deionized water, at least 4 equivalents of silver pentazole powder are added, the reaction is performed ultrasonically and in the dark, the precipitate is filtered, and the filtrate is concentrated to obtain the product; the second is the synthesis of 1,4,7,10-tetraazacyclododecane pentaazole nitrate complex salt, which differs from the first in that 1 equivalent of silver nitrate and at least 3 equivalents of silver pentazole powder are added. This invention, by controlling the amount of silver salt added, directly synthesizes dipentazole salt and pentaazole nitrate complex salt from 1,4,7,10-tetraazacyclododecane tetrahydrochloride in one step, solving the problems of difficult raw material synthesis and uncontrollable product structure, laying the foundation for the large-scale preparation and application of energetic materials.

Description

Technical Field

[0001] This invention relates to the field of energetic materials technology, and in particular to a controllable synthesis method for 1,4,7,10-tetraazacyclododecanepentazole salt. Background Technology

[0002] Pentazole anions, as important structural units in all-nitrogen compounds, have attracted much attention in research. In 2017, room-temperature and atmospheric-pressure stable pentazole anion salts (such as (N5)6(H3O)3(NH4)4Cl) and a series of metal complexes were successfully synthesized for the first time. Since then, researchers have successively developed various derivatives, including metal salts, non-metal salts, and eutectic compounds. Among them, polypentazole salts generated by the metathesis reaction of cyclic polyamine hydrochloride and silver pentazole have become a research hotspot in the field of energetic materials due to their ability to significantly improve the energy performance of the products.

[0003] However, existing technologies have significant drawbacks in the synthesis of 1,4,7,10-tetraazacyclododecane pentazonium salts: on the one hand, the dihydrochloride of 1,4,7,10-tetraazacyclododecane, as a potential synthetic raw material, is difficult to synthesize, which limits the preparation of subsequent pentazonium salts; on the other hand, existing synthetic methods are difficult to precisely control the product structure, making it impossible to efficiently and controllably prepare specific types of 1,4,7,10-tetraazacyclododecane pentazonium salts, thus restricting their application and development in the field of high-energy materials. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, the present invention aims to provide a controllable synthesis method for 1,4,7,10-tetraazacyclododecanepentazole salt. By controlling the amount of silver salt added, 1,4,7,10-tetraazacyclododecane tetrahydrochloride is used as a raw material to synthesize dipentazole salt and pentaazole nitrate complex salt in one step. This effectively solves the problems of difficult raw material synthesis and uncontrollable product structure, laying the foundation for the large-scale preparation and application of this type of energetic material.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] This invention provides a method for synthesizing 1,4,7,10-tetraazacyclododecanedipentazole salt, comprising the following steps:

[0007] Dissolve 1,4,7,10-tetraazacyclododecane tetrahydrochloride in deionized water to form a solution, then add not less than 4 equivalents of silver pentazolide powder and mix to form a reaction solution.

[0008] The reaction solution was subjected to multiple ultrasonic treatments, followed by a light-protected reaction.

[0009] After the reaction was completed, the precipitate in the reaction solution was removed by solid-liquid separation, and the resulting filtrate was concentrated to obtain 1,4,7,10-tetraazacyclododecanedipentazolium salt.

[0010] Preferably, the mass ratio of 1,4,7,10-tetraazacyclododecane tetrahydrochloride to deionized water is 1:100 to 200.

[0011] Preferably, the molar amount of silver pentazobium is 4 to 8 times the molar amount of 1,4,7,10-tetraazacyclododecane tetrahydrochloride.

[0012] Preferably, the ultrasonic treatment is performed 3 times, the interval between two adjacent ultrasonic treatments is 10 minutes, the light-protected reaction time is 1 hour, and the reaction temperature is 5-25°C.

[0013] Preferably, the chemical formula of the 1,4,7,10-tetraazacyclododecanedipentazolium salt is C8H12H2O. 22 N4(N5)2, its molecular structure is as follows:

[0014]

[0015] This invention also provides a method for synthesizing 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt, comprising the following steps:

[0016] Dissolve 1,4,7,10-tetraazacyclododecane tetrahydrochloride in deionized water to form a solution, then add 1 equivalent of silver nitrate and not less than 3 equivalents of silver pentazolium powder to form a reaction solution.

[0017] The reaction solution was subjected to multiple ultrasonic treatments, followed by a light-protected reaction.

[0018] After the reaction was completed, the precipitate in the reaction solution was removed by solid-liquid separation, and the resulting filtrate was concentrated to obtain 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt.

[0019] Preferably, the mass ratio of 1,4,7,10-tetraazacyclododecane tetrahydrochloride to deionized water is 1:100 to 200.

[0020] Preferably, the molar amount of silver nitrate is equal to the molar amount of 1,4,7,10-tetraazacyclododecane tetrahydrochloride; the molar amount of silver pentaazole is 3 to 5 times that of 1,4,7,10-tetraazacyclododecane tetrahydrochloride.

[0021] Preferably, the ultrasonic treatment is performed 3 times, the interval between two adjacent ultrasonic treatments is 10 minutes, the light-protected reaction time is 1 hour, and the reaction temperature is 5-25°C.

[0022] Preferably, the chemical formula of the 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt is C8H. 22 N4(N5)NO3 has the following molecular structural formula:

[0023]

[0024] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0025] (1) This invention realizes the controllable synthesis of 1,4,7,10-tetraazacyclododecanepentazole salt. Specifically, using 1,4,7,10-tetraazacyclododecanete hydrochloride as raw material, by adjusting the amount of silver salt added, 1,4,7,10-tetraazacyclododecanedipentazole salt and 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt can be synthesized in one step, thus realizing the control of the product structure.

[0026] (2) This invention simplifies the synthesis process and reduces the difficulty of obtaining raw materials. Since the synthesis of 1,4,7,10-tetraazacyclododecane dihydrochloride is difficult, this invention does not require the use of this difficult raw material. It directly and controllably converts the easily obtainable tetrahydrochloride into the target pentazolium salt. The synthesis process is simple and provides the possibility for its engineering application.

[0027] (3) The products obtained by this invention have good application potential. The 1,4,7,10-tetraazacyclododecanedipentazole salt and the 1,4,7,10-tetraazacyclododecanepentazole nitrate composite salt have high carbon, hydrogen and nitrogen content, making them potential high-energy fuels in solid rocket propellants and having important application value in the field of energetic materials. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 Crystal structure diagram of 1,4,7,10-tetraazacyclododecanedipentazolium salt provided in Example 1 of the present invention;

[0030] Figure 2 This is a unit cell packing diagram of 1,4,7,10-tetraazacyclododecanedipentazolium salt provided in Example 1 of the present invention;

[0031] Figure 3 The carbon NMR spectrum of 1,4,7,10-tetraazacyclododecanedipentazole salt provided in Example 1 of this invention;

[0032] Figure 4 Crystal structure diagram of 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt provided in Example 2 of the present invention;

[0033] Figure 5 This is a unit cell packing diagram of the 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt provided in Example 2 of the present invention;

[0034] Figure 6 The carbon NMR spectrum of the 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt provided in Example 2 of the present invention;

[0035] Figure 7 The infrared spectra of the complex salts of 1,4,7,10-tetraazacyclododecanedipentazole salt and 1,4,7,10-tetraazacyclododecanepentazole nitrate provided in Examples 1 and 2 of this invention are shown. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] Example 1

[0039] This embodiment provides a method for synthesizing 1,4,7,10-tetraazacyclododecanedipentazole salt, comprising the following steps:

[0040] Dissolve 1,4,7,10-tetraazacyclododecane tetrahydrochloride in deionized water to form a solution, then add at least 4 equivalents of silver pentaazole powder and mix to form a reaction solution; wherein the mass ratio of 1,4,7,10-tetraazacyclododecane tetrahydrochloride to deionized water is 1:100-200; and the molar amount of silver pentaazole is 4 to 8 times the molar amount of 1,4,7,10-tetraazacyclododecane tetrahydrochloride.

[0041] In this embodiment, the specific steps are as follows: 318.11 mg of 1,4,7,10-tetraazacyclododecane tetrahydrochloride is dissolved in 30 mL of deionized water at 25 °C, and then 4 equivalents of silver pentazonite powder, with a mass of 711.48 mg, is added.

[0042] The reaction solution was subjected to multiple ultrasonic treatments, followed by a light-protected reaction. The ultrasonic treatments were performed three times, with an interval of 10 minutes between each ultrasonic treatment. The light-protected reaction lasted for 1 hour at a temperature of 25°C.

[0043] After the reaction was completed, the precipitate in the reaction solution was removed by solid-liquid separation, and the resulting filtrate was concentrated to obtain 1,4,7,10-tetraazacyclododecanedipentazolium salt, which is a white solid with a yield of 48%.

[0044] According to the above method, the chemical formula of the 1,4,7,10-tetraazacyclododecanedipentazol salt is C8H. 22 N4(N5)2, its molecular structure is as follows:

[0045]

[0046] The single-crystal data for its monohydrate are as follows:

[0047] Molecular formula: C8H 24 N 14 O;

[0048] Molecular weight: 332.41;

[0049] Crystal system: Orthorhombic;

[0050] Group chat: Ima2;

[0051] Unit cell parameters: α = β = γ = 90°;

[0052] Crystal volume:

[0053] Z = 8;

[0054] Density: 1.381 g·cm³ -3 (170K).

[0055] After obtaining the 1,4,7,10-tetraazacyclododecanedipentazolium salt using the above synthetic method, it was characterized, and the results are as follows: Figure 1 and Figure 2 As shown. Figure 1 The atomic connection and spatial configuration of the 1,4,7,10-tetraazacyclododecane cation and the pentazolium anion are clearly demonstrated: the C and N atom bonding of the cyclic polyamine cation matches the polynitrogen ring structure of the pentazolium anion, directly verifying that the molecular structure of the synthesized product matches the chemical formula C8H. 22 The complete consistency with N4(N5)2 proves that the method of this embodiment can successfully prepare the target energetic compound, and the atomic bonding and arrangement within the molecule meet the design expectations. Figure 2The spatial arrangement of molecules within a crystal unit cell is visually demonstrated: molecules are stacked in a periodic and regular manner within the unit cell; molecular units composed of 1,4,7,10-tetraazacyclododecane cations and pentazolium anions are arranged along the a-axis of the unit cell. b-axis c-axis Alternating or parallel orientations form layered or network-like interwoven three-dimensional stacked structures. This is combined with its orthorhombic crystal system (α=β=γ=90°), the symmetry of the point group Ima2, and the unit cell volume. With a packing parameter of Z=8, the packing characteristics of this crystal can be clearly defined as follows: molecules are arranged in an orderly manner along three mutually perpendicular crystal axes within an orthogonal symmetry framework, forming a close-packed structure with a specific periodicity through appropriate space filling. This packing mode is consistent with 1.381 g·cm⁻¹. -3 The crystal density at (170K) is directly related to the molecular packing of energetic materials, reflecting the intrinsic connection between the molecular packing and macroscopic properties.

[0056] This embodiment also simultaneously performs carbon nuclear magnetic resonance spectroscopy (NMR) measurements, and the results are as follows: Figure 3 As shown, the carbon spectrum exhibits only a single characteristic chemical shift peak, corresponding to the signal of the 1,4,7,10-tetraazacyclododecane cation carbon skeleton, i.e. 13 C NMR (DMSO-d6): 43.96 ppm. Based on a single specific chemical shift value shown in the carbon spectrum, which matches the symmetrical configuration of the cation determined by the crystal structure, the symmetrical existence and uniform connection mode of the 1,4,7,10-tetraazacyclododecane cation carbon skeleton are verified, further confirming the accuracy of the molecular structure of the synthesized product from a molecular spectral perspective.

[0057] Example 2

[0058] A method for synthesizing 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt is provided, comprising the following steps:

[0059] Dissolve 1,4,7,10-tetraazacyclododecane tetrahydrochloride in deionized water to form a solution, then add 1 equivalent of silver nitrate and not less than 3 equivalents of silver pentaazole powder to form a reaction solution; wherein, the mass ratio of 1,4,7,10-tetraazacyclododecane tetrahydrochloride to deionized water is 1:100-200; the molar amount of silver nitrate is equal to the molar amount of 1,4,7,10-tetraazacyclododecane tetrahydrochloride; and the molar amount of silver pentaazole is 3-5 times that of 1,4,7,10-tetraazacyclododecane tetrahydrochloride.

[0060] In this embodiment, the specific steps are as follows: 318.11 mg of 1,4,7,10-tetraazacyclododecane tetrahydrochloride is dissolved in 30 mL of deionized water at 20 °C, and 1 equivalent of silver nitrate and 4 equivalents of pentazolium silver powder are added, wherein the mass of silver nitrate is 169.87 mg and the mass of pentazolium silver is 711.48 mg.

[0061] The reaction solution was subjected to ultrasonic treatment three times, with an interval of 10 minutes between two adjacent ultrasonic treatments, and then the reaction was carried out at 25°C in the dark for 1 hour.

[0062] After the reaction was completed, the precipitate in the reaction solution was removed by solid-liquid separation, and the resulting filtrate was concentrated to obtain 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt.

[0063] According to the above method, the chemical formula of the 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt is C8H. 22 N4(N5)NO3 has the following molecular structural formula:

[0064]

[0065] Its single-crystal data are as follows:

[0066] Molecular formula: C8H 22 N 10 O3;

[0067] Molecular weight: 306.36;

[0068] Crystal system: Orthorhombic;

[0069] Group: Pmn21;

[0070] Unit cell parameters: α = β = γ = 90°;

[0071] Crystal volume:

[0072] Z = 2;

[0073] Density: 1.350 g·cm³ -3 (298K).

[0074] After obtaining the 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt using the above synthesis method, it was characterized, and the results are as follows. Figure 4 and Figure 5 As shown. Figure 4The atomic connections and spatial configurations of the 1,4,7,10-tetraazacyclododecane cation, pentazolium anion, and nitrate anion are clearly demonstrated: the C and N atom bonds of the cyclic polyamine cation match the polynitrogen ring structure of the pentazolium anion and the configuration of the nitrate anion, directly verifying that the molecular structure of the synthesized product matches the chemical formula C8H. 22 The complete consistency of N4(N5)NO3 proves that the method of this embodiment can successfully prepare the target energetic compound, and the atomic bonding and arrangement within the molecule meet the design expectations.

[0075] Figure 5 The spatial arrangement of molecules within a crystal unit cell is visually demonstrated: molecules are stacked in a periodic and regular manner within the unit cell; molecular units composed of 1,4,7,10-tetraazacyclododecane cations, pentazolium anions, and nitrate anions are arranged along the a-axis of the unit cell. b-axis c-axis Alternating or parallel orientations form layered or network-like interwoven three-dimensional stacked structures. This is combined with its orthorhombic crystal system (α=β=γ=90°), the symmetry characteristics of the point group Pmn21, and the unit cell volume... With a packing parameter of Z=2, the packing characteristics of this crystal can be clearly defined as follows: molecules are arranged in an orderly manner along three mutually perpendicular crystal axes within an orthogonal symmetry framework, forming a close-packed structure with a specific periodicity through appropriate space filling. This packing mode is consistent with 1.350 g·cm⁻¹. -3 The crystal density of (298K) is directly related to the intrinsic relationship between molecular packing and macroscopic properties of energetic materials.

[0076] This embodiment also simultaneously performs carbon nuclear magnetic resonance spectroscopy (NMR) measurements, and the results are as follows: Figure 6 As shown, the characteristic chemical shift peaks in the carbon spectrum correspond to the signals of the 1,4,7,10-tetraazacyclododecane cation carbon skeleton. 13 C NMR (DMSO-d6): 43.84 ppm, 49.06 ppm. This means that carbon atoms in different chemical environments within the molecule exhibit specific chemical shift values ​​in the spectrum due to differences in the density of their surrounding electron clouds, which match the cation configuration determined by the crystal structure.

[0077] The present invention also characterized the products synthesized in Examples 1 and 2 by infrared spectroscopy, and the results are as follows: Figure 7 As shown. (Refer to...) Figure 7Infrared spectrum of 1,4,7,10-tetraazacyclododecanedipentazolium salt, IR (ATR): 3306.91, 3000.14, 2861.00, 2015.36, 1745.62, 1571.30, 1449.47, 1379.38, 1274.46, 1247.97, 1206.86, 1128.46, 1080.38, 1068.23, 1026.85, 972.11, 907.61, 887.85, 832.19, 793.41, 737.89, 634.19, 623.92, 585.23, 530.68 cm⁻¹ -1 It can be observed that 2015.36cm -1 The characteristic peak at that location corresponds to the pentazolium anion (N5). - The skeletal vibration of 3306.91cm -1 The peak represents the stretching vibration of the NH bond in the cation, at 1571.30 cm⁻¹. -1 and 1449.47cm -1 The peaks were correlated with the CN bond bending vibrations of the 1,4,7,10-tetraazacyclododecane cation, thus verifying the presence and bonding mode of the pentazolium anion and the cyclic polyamine cation in the molecule, consistent with the crystal structure and CMR results.

[0078] See Figure 7 The infrared spectrum (IR(ATR)) of the 1,4,7,10-tetraazacyclododecanepentazole nitrate complex is shown below: 3341.34, 3256.40, 2996.08, 2801.60, 2409.39, 2137.84, 2033.42, 1595.27, 1486.95, 1440.39, 1381.41. 1296.69, 1272.27, 1212.02, 1147.94, 1117.22, 1082.38, 1065.45, 1045.05, 1009.65, 971.62, 955.03, 933.38, 913.12, 821.56, 785.98, 747.95, 527.85cm -1 It can be observed that the infrared spectrum of the 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt exhibits multiple characteristic absorption peaks, which correspond to the vibrations of different functional groups in the molecule. Among them, the peak at 3341.34 cm⁻¹ is particularly prominent. -1 and 3256.40cm -1 The nearby absorption peak can be attributed to the stretching vibration of the NH bond; 2996.08 cm⁻¹ -1 and 2801.60cm -1 The absorption peak at 2137.84 cm⁻¹ is related to the stretching vibration of the CH bond. -1and 2033.42cm -1 The absorption peak may correspond to the characteristic vibration of the pentazolium anion; 1595.27 cm⁻¹ -1 The absorption peaks around the nitrate anion are related to the vibrations of the nitrate anion. The presence of these characteristic peaks further verifies the molecular structure of the composite salt, which, along with the characterization results such as the crystal structure, confirms that the synthesized product conforms to the expected chemical structure.

[0079] Therefore, by adopting the above-mentioned controllable synthesis method of 1,4,7,10-tetraazacyclododecanepentazole salt, and by adjusting the amount of silver salt added, 1,4,7,10-tetraazacyclododecane tetrahydrochloride can be directly used as raw material to synthesize dipentazole salt and pentaazole nitrate complex salt in one step. This effectively solves the problems of difficult raw material synthesis and uncontrollable product structure, and lays the foundation for the large-scale preparation and application of this type of energetic material.

[0080] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0081] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for synthesizing 1,4,7,10-tetraazacyclododecanedipentazolium salt, characterized in that, Includes the following steps: Dissolve 1,4,7,10-tetraazacyclododecane tetrahydrochloride in deionized water to form a solution, then add not less than 4 equivalents of silver pentaazole powder and mix to form a reaction solution; the molar amount of silver pentaazole is 4 to 8 times the molar amount of 1,4,7,10-tetraazacyclododecane tetrahydrochloride. The reaction solution was subjected to multiple ultrasonic treatments, followed by a light-protected reaction. The ultrasonic treatments were performed three times, with an interval of 10 minutes between each ultrasonic treatment. The light-protected reaction lasted for 1 hour, and the reaction temperature was 5-25°C. After the reaction was completed, the precipitate in the reaction solution was removed by solid-liquid separation, and the resulting filtrate was concentrated to obtain 1,4,7,10-tetraazacyclododecanedipentazolium salt. The chemical formula of the 1,4,7,10-tetraazacyclododecanedipentazole salt is C8H. 22 N4(N5)2, its molecular structure is as follows: 。 2. The method for synthesizing 1,4,7,10-tetraazacyclododecanedipentazolium salt according to claim 1, characterized in that, The mass ratio of the 1,4,7,10-tetraazacyclododecane tetrahydrochloride to deionized water is 1:100~200.

3. A method for synthesizing a 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt, characterized in that, Includes the following steps: 1,4,7,10-tetraazacyclododecane tetrahydrochloride was dissolved in deionized water to form a solution. Then, 1 equivalent of silver nitrate and not less than 3 equivalents of silver pentazolium powder were added and mixed to form a reaction solution. The molar amount of silver nitrate was equal to that of 1,4,7,10-tetraazacyclododecane tetrahydrochloride. The molar amount of silver pentazolium was 3 to 5 times that of 1,4,7,10-tetraazacyclododecane tetrahydrochloride. The reaction solution was subjected to multiple ultrasonic treatments, followed by a light-protected reaction. The ultrasonic treatments were performed three times, with an interval of 10 minutes between each ultrasonic treatment. The light-protected reaction lasted for 1 hour, and the reaction temperature was 5-25°C. After the reaction was completed, the precipitate in the reaction solution was removed by solid-liquid separation, and the resulting filtrate was concentrated to obtain 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt; The chemical formula of the 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt is C8H. 22 N4(N5)NO3 has the following molecular structural formula: 。 4. The method for synthesizing a 1,4,7,10-tetraazacyclododecanepentazole nitrate complex salt according to claim 3, characterized in that, The mass ratio of the 1,4,7,10-tetraazacyclododecane tetrahydrochloride to deionized water is 1:100~200.

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