A nitrogen-rich energetic tetrazine double inner salt skeleton compound and a preparation method thereof

Abstract

The application provides a nitrogen-rich energetic tetrazine double internal salt skeleton compound and a preparation method, and a structural formula is as follows: in the formula, R1 is -NH2, -NO2 or -NHNO2; and R2 is -NH2, -NO2 or -NHNO2. The nitrogen-rich energetic tetrazine double internal salt skeleton compound is an energetic organic small molecule, the nitrogen content of the compound is 69.12%, and the compound has excellent detonation performance and heat resistance. The highest heat decomposition peak temperature of the energetic compound related to the skeleton is up to 473.2 DEG C, the highest detonation velocity is up to 9470 m / s, and the highest detonation pressure is up to 46.8 GPa.

Description

Technical Field

[0001] The invention belongs to the technical field of explosives, relates to nitrogen-rich fused ring energetic compounds, and particularly relates to a nitrogen-rich energetic tetrazine bisinium salt skeleton compound and a preparation method thereof. Background Art

[0002] Explosives are the fundamental energy source for modern weaponry to deliver destructive power. Their energy directly determines their destructive capabilities, while their safety and thermal stability directly impact their environmental adaptability. Explosives research has consistently centered around these two key aspects, aiming to maximize explosive energy while ensuring safety during production, transportation, and use.

[0003] To achieve this goal, scientists have conducted research on different explosive molecular skeletons such as aliphatic hydrocarbons, cycloalkanes, azacycloalkanes, benzene rings, nitrogen heteroaromatic rings, and nitrogen heterobridged cycloalkanes, and have developed many potential heat-resistant and low-sensitivity single-molecule explosives, such as diaminodinitroethylene (FOX-7), 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX), 4,8-dipicrylbisfurazanopyrazine (TNBP), hexanitropine (HNS), 2,6-diamino-3,5-dinitro-1,3,5,7-tetraazacyclooctane (HMX), 4,8-dipicrylbisfurazanopyrazine (TNBP), hexanitropine (HNS), 2,6-diamino-3,5-dinitro-1,3,5-dinitro-2,2-diamino ...4,8-diamino-3,5-dinitro-1,3,5-dinitro-2,2-diamino-1,3,5,7-tetraazacyclooc The development of these heat-resistant and low-sensitivity elemental explosives has broadened the research scope of energetic materials and also gradually promoted the application research of energetic materials.

[0004] However, the current heat-resistant energetic materials have the following problems:

[0005] High-energy heat-resistant explosives have poor heat resistance and traditional high-energy explosives have low energy levels. Therefore, the development of new heat-resistant and insensitive high-energy explosives can, on the one hand, meet the needs of national defense and military modernization (hypersonic weapons are one of the advanced strategic weapons that major countries are competing to research. Their ultra-high flight speed (more than Mach 5) causes intense friction between the shell and the atmosphere, resulting in a rapid increase in temperature and significant aerodynamic effects); on the other hand, it can meet the needs of deep well energy operations (perforating bullets need to be able to withstand high ambient temperatures and reliably complete storage and operations). In addition, in the field of energy extraction: in recent years, "ultra-high temperature (230°C) hot dry rock well fracturing technology" is still a blank in my country's scientific and technological field (hot dry rock refers to underground The dense hot rock mass, which has a lower temperature of 150°C and is devoid of water or other fluids, contains enormous amounts of thermal energy. It has the advantages of large reserves, wide distribution, and no pollution, making it a clean, green energy source with great development value. The Tianjin Geological Survey Center (Institute) of the China Geological Survey is collaborating with the Hydrogeological and Environmental Geological Survey Center to explore new energy sources. In recent years, provinces across China have been exploring clean geothermal resource development. Qinghai has explored and developed dozens of high-temperature and ultra-high-temperature dry-hot rock wells. The dry-hot reformed layer, located approximately 4,000 meters below sea level, is composed of hard, dense basalt or carbonate rocks. Well temperatures range from 210-230°C. Openhole or screened completions are used with 7-inch casing. Conventional perforation combined with hydraulic sand fracturing has been ineffective. Combined perforation requires continuous cooling through surface pumped circulating water, which is very costly. The goal is to find a feasible solution to improve heat transfer efficiency for well sections between 200 and 300 meters. This technology draws on the principles of high-energy gas fracturing and fracture creation technology. The development involves the detonation of ultra-high-temperature energetic materials with a temperature resistance of 230°C, generating large amounts of high-temperature, high-pressure gas to create fractures. Fracturing can be performed independently or in combination with perforation. The ultra-high-temperature, heat-resistant, and insensitive explosives required for this technology are a key breakthrough in this area.

[0006] The performance parameters of commonly used heat-resistant explosives are shown in Table 4 below.

[0007] Table 4 Performance parameters of commonly used heat-resistant explosives

[0008]

[0009]

[0010] The literature review found that the well-known 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) (Nandy A.K., Thirupathi N., Mandal AK, et al. Assay of the thermally stable, insensitive, high explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) [J]. Cent. Eur. J. Energy Mater., 2014, 11, 295-305; Pagoria PA Comparison of the structure, synthesis, and properties of insensitive energetic compounds[J].Propell.Explos.Pyrotech.,2016,41,452-469), hexanitrostilbene (HNS) (Zhu Zhongqin, Shao Yanli, Lin Qiuhan, Wang Pengcheng, Lu Ming. Research progress on preparation and application of heat-resistant explosive hexanitrostilbene [J]. Journal of Explosives and Propellants,2018,41(4):319-325), 2,6-dipicrylamino-3,5-dinitropyridine (PYX) ( TM, Stierstorfer J., Weyrauther M., et al. Synthesis and investigation of 2,6-bis(picrylamino)-3,5-dinitro-pyredine(PYX)and its salts[J]. Chem.-Eur. J., 2016, 22, 8619-8626). So far, only triaminotrinitrobenzene (TATB) can meet the 11 indicators of insensitive elemental explosives. It has a thermal decomposition temperature of 360°C and very low mechanical sensitivity. It will not produce detonation when encountering external conditions such as high-altitude falling, strong impact, bullet shooting and flame roasting. It is called "wood explosive". Despite this, TATB has a lower energy level (detonation velocity D v =8114m / s, explosion pressure P = 30.4GPa) and the high cost of synthesis have limited its application. However, analysis of the insensitivity mechanism of TATB reveals that the extensive hydrogen bonding and graphite-like layered crystal stacking in its structure are key factors contributing to its high safety. This has important implications for the design and synthesis of new insensitive explosive molecules and the modification and optimization of existing energetic materials. Therefore, the design of a high-energy, heat-resistant, low-sensitivity elemental explosive with a "wood dynamite"-like framework is urgently needed! Summary of the Invention

[0011] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a nitrogen-rich energetic tetrazine bisinium salt skeleton compound and a preparation method, so as to solve the technical problem that the performance of nitrogen-rich fused ring energetic compounds in the existing technology needs to be further improved.

[0012] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0013] A nitrogen-rich, energetic tetrazine double inner salt skeleton compound, the structural formula of the compound is:

[0014]

[0015] Where:

[0016] R1 is -NH2, -NO2 or -NHNO2;

[0017] R2 is -NH2, -NO2 or -NHNO2.

[0018] Preferably, the nitrogen-rich energetic tetrazine bisinium salt skeleton compound is compound TYX-1, compound TYX-2, compound TYX-3, compound TYX-4 or compound TYX-5.

[0019] The structural formula of the compound TYX-1 is

[0020] The structural formula of the compound TYX-2 is

[0021] The structural formula of the compound TYX-3 is

[0022] The structural formula of the compound TYX-4 is

[0023] The structural formula of the compound TYX-5 is

[0024] Preferably, the thermal decomposition peak temperature of the nitrogen-rich energetic tetrazine bisinol salt skeleton compound is as high as 473.2°C.

[0025] Preferably, the detonation velocity of the nitrogen-rich energetic tetrazine bisinium salt skeleton compound is 9470 m / s.

[0026] Preferably, the explosion pressure of the nitrogen-rich energetic tetrazine bisinium salt skeleton compound is 46.8 GPa.

[0027] Preferably, the nitrogen-rich energetic tetrazine bisinium salt skeleton compound has an impact sensitivity greater than 40J and a friction sensitivity greater than 360N.

[0028] The present invention also protects a method for preparing the nitrogen-rich energetic tetrazine bisinium salt skeleton compound as described above, the method comprising the following steps:

[0029] Step 1: Compound 1 and 5-aminotetrazole are used as raw materials, sulfolane is added, and the mixture is heated to 100-150° C. for reaction. After the reaction, the mixture is separated and purified to obtain compound 2.

[0030] The structural formula of the compound 1 is:

[0031]

[0032] The structural formula of the compound 2 is:

[0033]

[0034] Step 2: Compound 2 is added to polyphosphoric acid in batches, reacted at a temperature of 150-220° C., and after the reaction, the compound TYX-1 is obtained by separation and purification.

[0035] Furthermore, the method further includes step three; said step three includes the following steps:

[0036] Compound TYX-1 was used as raw material and reacted in fuming nitric acid, concentrated H2SO4 and Na2MoO4 H2O2 solution at 0°C to prepare compound TYX-2.

[0037] Alternatively, compound TYX-1 is used as a raw material, and reacted in fuming nitric acid, concentrated H2SO4, and KMnO4 in H2O2 solution at 0°C to obtain compound TYX-3.

[0038] Alternatively, compound TYX-1 is used as a raw material and reacted in concentrated nitric acid at 15-25°C to obtain compound TYX-4.

[0039] Alternatively, compound TYX-1 is used as a raw material, and the reaction solution is stirred at 0-5°C for 0.5-3.0 h in concentrated nitric acid; after the reaction solution stabilizes, it is stirred at room temperature for 1.0-6.0 h, and then stirred at 50-80°C for 4.0-12.0 h to react to obtain compound TYX-5.

[0040] Preferably, the specific process of step one includes the following steps:

[0041] Step 101: Compound 1 and 5-aminotetrazole are weighed and added to a reaction flask, and sulfolane is also weighed and added.

[0042] Step 102: heating the reaction solution in step 101 to 100-150° C. and reacting for 18-30 hours.

[0043] Step 103: After the reaction is completed, the reaction solution is cooled to 50-80° C., and a high-boiling-point, highly polar solvent is added to dilute the reaction solution. It is observed that a reddish-brown solid is precipitated in the reaction solution.

[0044] Step 104: filter out the reddish-brown solid powder and wash the reddish-brown solid powder.

[0045] Step 105: Dry the obtained reddish-brown solid powder to obtain a completely dried reddish-brown solid crude product.

[0046] Step 106: reflux the completely dried reddish-brown solid crude product in a high-boiling-point, highly polar solvent, cool, filter, wash, and dry to obtain an orange-yellow solid compound 2.

[0047] In step 1, preferably, the high-boiling-point, highly polar solvent is N,N-dimethylformamide, dimethyl sulfoxide or nitrogen-methyl pyrrolidone.

[0048] Preferably, the specific process of step 2 includes the following steps:

[0049] Step 201, weighing compound 2 and polyphosphoric acid.

[0050] Step 202 , adding compound 2 to polyphosphoric acid in batches under stirring at 100-165° C. to form a reaction solution.

[0051] Step 203: heating the reaction solution to 150-220° C. and reacting at the temperature for 3.0-10.0 hours.

[0052] Step 204: After the reaction is completed, the resulting mixture is cooled to 60-70° C., and distilled water is added to dilute the mixture. A yellow solid powder is precipitated, and the mixture is placed at room temperature for 6.0-24.0 hours.

[0053] Step 205: Filter out the yellow solid precipitate, and wash it repeatedly with water and methanol for 3 to 5 times.

[0054] Step 206: Dry the obtained yellow solid precipitate to obtain a bright red solid, which is compound TYX-1.

[0055] The nitrogen-rich energetic tetrazine bisinium salt skeleton compound is used as an explosive.

[0056] The explosive is an ultra-high temperature heat-resistant insensitive explosive, a heat-resistant insensitive explosive or a high-energy insensitive explosive.

[0057] The ultra-high temperature refers to a high temperature greater than 400°C.

[0058] Compared with the prior art, the present invention has the following technical effects:

[0059] (I) The nitrogen-rich energetic tetrazine double inner salt skeleton compound of the present invention is a class of energetic organic small molecules with a nitrogen content of 69.12%. It has relatively excellent detonation performance and heat resistance: the energetic compounds involved in this skeleton have a maximum thermal decomposition peak temperature of up to 473.2°C, a maximum detonation velocity of 9470m / s, and a maximum explosion pressure of 46.8GPa.

[0060] (II) The sensitivity of the nitrogen-rich energetic tetrazine bisinium salt skeleton compound of the present invention can reach: impact sensitivity>40J, friction sensitivity>360N.

[0061] (III) The raw materials of the present invention are cheap and readily available: the raw materials and nitrating agents used are all commercial reagents. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is a physical picture of the TYX-1 compound.

[0063] Figure 2 This is the X-ray single crystal diffraction structure of TYX-1.

[0064] Figure 3 This is a scanning electron micrograph of the TYX-1 compound.

[0065] Figure 4 This is the X-ray single crystal diffraction structure of TYX-2.

[0066] Figure 5 This is a scanning electron micrograph of the TYX-2 compound.

[0067] Figure 6 This is the DSC thermal decomposition diagram of TYX-1.

[0068] Figure 7 This is the DSC thermal decomposition diagram of TYX-2.

[0069] Figure 8 This is the DSC thermal decomposition diagram of TYX-3.

[0070] Figure 9 This is the DSC thermal decomposition diagram of TYX-4.

[0071] Figure 10 This is the DSC thermal decomposition diagram of TYX-5.

[0072] Figure 11 The DSC curves of TYX-1 at different heating rates.

[0073] Figure 12 This is the α-T curve showing the conversion rate α of TYX-1 changing with temperature.

[0074] Figure 13This is the Ea-α curve calculated by the Friedman method for TYX-1.

[0075] Figure 14 Assembly diagram of test specimens for slow-bake heat resistance test.

[0076] Figure 15 This is the appearance of the sample for slow-baking heat resistance test after slow-baking at 350℃ for 60.0h.

[0077] The specific contents of the present invention are further explained in detail below with reference to the embodiments. DETAILED DESCRIPTION

[0078] It should be noted that, unless otherwise specified, all raw materials in the present invention are raw materials known in the prior art.

[0079] In the present invention, the nitrogen-rich energetic tetrazine bisinium salt skeleton compound can also be referred to as a nitrogen-rich energetic bisinium salt bis([1,2,4]triazole)[1,5-b1',5'-e][1,2,4,5]tetrazine skeleton compound. The structural formula of the nitrogen-rich energetic tetrazine bisinium salt skeleton compound is as follows:

[0080]

[0081] Where:

[0082] R1 is -NH2, -NO2 or -NHNO2;

[0083] R2 is -NH2, -NO2 or -NHNO2.

[0084] The concept of the present invention is:

[0085] The construction of a binary nitrogen heterocyclic structure has been relatively mature in methodology, but according to the knowledge of the present application, there are few reports on the construction of a ternary or multiplanar or quasi-planar nitrogen heterocyclic structure of heat-resistant explosive or high-energy explosive molecules. The present application believes that it is very difficult to obtain a planar or quasi-planar molecular structure while synthesizing a ternary or multiplanar nitrogen heterocyclic structure through the design of reactants in terms of synthesis methodology. On the one hand, the present application selects a step-by-step reaction method: first, a planar or quasi-planar structure of a heterocyclic mother ring structure is synthesized in a relatively simple method through the selection of reactants; and then, a simple oxidation-reduction reaction is used to finally obtain amino or nitro groups and other energy group structures located on two different rings; at the same time, the strategy of constructing a large conjugated system and the strategy of introducing amino groups to form strong hydrogen bonds are used, so as to obtain an energetic molecule with a higher thermal decomposition temperature. On the other hand, the present application believes that if the molecular structure can be designed skillfully, the energetic groups (amino, nitro, azido group, azo group, nitrate group, nitroxide structure, etc.) can be efficiently introduced by chemical methods and reasonably arranged, so that the intramolecular and intermolecular hydrogen bond interactions and the intermolecular dipole-dipole interactions can be scientifically coordinated, it is possible to obtain a new energetic molecule with an absolutely planar or quasi-planar configuration, to enrich the structural connotation of ternary or multiplanar heterocyclic explosive molecules with absolutely two-dimensional layered structure. The ternary or multiplanar nitrogen heterocyclic structure constructed by the above method can make the amino group and the nitro group located at both ends of the molecule, so that the intermolecular dipole-dipole (the nitrogen atom with positive charge on the heterocyclic ring and the oxygen atom with negative charge on the nitro group) interaction can have a better extension space, so as to obtain a planar or quasi-planar energetic molecule.

[0086] Based on the above idea, the present application selects to construct a tetrazine and bis-tetrazole ring structure, because the tetrazine and bis-tetrazole ring structure has the advantages of the tetrazine ring and the tetrazole ring skeleton structure alone, and has a 1+1>2 effect. Specifically:

[0087] Firstly, the triazole ring in the molecular structure is a "potential nitro" inner ring structure, one ring contains 3 nitrogen atoms, the nitrogen content and the crystal density of the molecule are higher, and the tetrazine and bis-tetrazole ring has a larger conjugated structure and higher nitrogen content than the single ring, so that their enthalpy of formation, density and oxygen balance performance are improved, which is beneficial to improve the energy density of the energetic molecule.

[0088] Second, the structure of tetrazine-bis-tetrazole is compact. The C-C bond and C-N bond lengths in the tetrazine ring are basically the same. All atoms are highly coplanar, and the molecules are stacked in a π-π structure. The molecule has high aromaticity and structural stability. On the one hand, it makes the density higher, and on the other hand, it effectively increases the energy level of the energetic compound, thereby having better detonation performance. In addition, it has positive significance for optimizing the safety performance (impact sensitivity, friction sensitivity, electrostatic spark sensitivity, etc.) and thermal stability (thermal decomposition temperature) of energetic molecules.

[0089] Third, according to the principle of "avoiding the introduction of energetic groups with acidic hydrogen", the bistriazole tetrazine ring is very suitable as the parent structure of heat-resistant energetic compounds. By further introducing energetic groups such as nitro groups, it is expected that new high-heat-resistant energetic compounds can be designed. Because acidic hydrogen may lead to poor thermal stability, it is easy to deteriorate or even corrode the shell under long-term high temperature or storage conditions; (4) The tetrazine and bistetrazole nitrogen-containing fused rings are five-membered rings and six-membered rings. The tension energy of the structure itself is relatively small. At the same time, the number of continuously connected nitrogen atoms in the structure does not exceed six, which makes the chemical bonds in the molecule relatively stable, and thus makes the structure itself have good stability.

[0090] Based on this, the present invention designs a series of compounds of the double inner salt bis([1,2,4]triazole)[1,5-b:1',5'-e][1,2,4,5]tetrazine type skeleton based on the structure of the bistriazole tetrazine fused heterocyclic structure molecular skeleton. The influence of the parent structure and energetic groups on the compound structure and detonation performance (formation enthalpy and detonation pressure) is studied by using quantum chemical density functional theory. It is expected to obtain a series of energetic compound molecular structures with excellent performance. It is expected that this type of skeleton will simultaneously meet the requirements of ultra-high temperature heat-resistant insensitivity, heat-resistant insensitivity and high-energy insensitive explosives.

[0091] The bis([1,2,4]triazole)[1,5-b:1',5'-e][1,2,4,5]tetrazine skeleton structure of the present invention is synthesized for the first time, and there is no related report of this structure in the previous literature.

[0092] Specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made on the basis of the technical solution of this application fall within the protection scope of the present invention.

[0093] Example 1:

[0094] This example provides a method for preparing a nitrogen-rich energetic tetrazine bis-indole skeleton compound, wherein the nitrogen-rich energetic tetrazine bis-indole skeleton compound is compound TYX-1. The method comprises the following steps:

[0095]

[0096] Step 1, preparation of compound 2:

[0097] Step 101: 1.0 equiv of compound 1 and 2.2 equiv of 5-aminotetrazole (5-AT) were weighed and added to a reaction flask, and 40.0 equiv of sulfolane was also weighed and added to the reaction flask.

[0098] Step 102: Heat the reaction solution in the reaction flask in step 101 to 150° C., react for 18 to 30 hours, and monitor the reaction progress using a TLC plate.

[0099] Step 103: After the reaction is completed, the reaction solution is cooled to 60° C., and 40 mL of a high-boiling-point, highly polar solvent is added to dilute the reaction solution. It is observed that a reddish-brown solid is precipitated in the reaction solution.

[0100] The high-boiling-point polar solvent is N,N-dimethylformamide, dimethyl sulfoxide or nitrogen-methylpyrrolidone.

[0101] Step 104: filter out the reddish-brown solid powder, and repeatedly wash the reddish-brown solid powder with deionized water, methanol or ethanol for 3 to 5 times.

[0102] Step 105 , the obtained reddish-brown solid powder is placed in a tray and placed in a vacuum drying oven at 60° C. for drying for 6.0 to 12.0 hours to obtain a completely dried reddish-brown solid crude product.

[0103] Step 106: Place the completely dried reddish-brown solid crude product in 10.0 equiv of a high-boiling-point, highly polar solvent and reflux for 1.0 to 20.0 h, cool, filter, wash, and dry to obtain an orange-yellow solid compound 2.

[0104] Step 2, preparation of compound TYX-1:

[0105] Step 201 , weigh 1.0 equiv of compound 2 and 20.0 equiv of polyphosphoric acid (PPA).

[0106] Step 202 : Add compound 2 to polyphosphoric acid in batches at 160° C. with rapid stirring to form a reaction solution.

[0107] Step 203: Heat the reaction solution to 210° C. and react at this temperature for 3.0 to 10.0 hours, and monitor the reaction progress using a TLC plate.

[0108] Step 204: After the reaction is completed, the resulting mixture is cooled to 65° C., and 40.0 equiv of distilled water is added to dilute the mixture. A yellow solid powder is precipitated, and the mixture is left at room temperature for 6.0 to 24.0 hours.

[0109] Step 205: Filter out the yellow solid precipitate, and wash it repeatedly with 40.0 equiv of water and methanol for 3 to 5 times.

[0110] Step 206: Place the obtained yellow solid precipitate into a tray and place it in a vacuum drying oven at 50-60° C. for drying for 6.0-20.0 hours to obtain a bright red solid, namely compound TYX-1.

[0111] Structure identification:

[0112] Elemental analysis: Anal.calcd for C4H4N 14 :C,25.00;H,2.10;N,72.90; Found:C,25.10;H,2.22;N,72.68.

[0113] Infrared spectrum (KBr, cm -1 ):3314, 3127 (-NH2 stretching vibration), 1638, 1571 (-NH2 in-plane deformation vibration), 1389 (CN stretching vibration), 1121, 745, 679 (-NH2 rocking vibration).

[0114] 1 H NMR(DMSO-d6,400MHz): δ7.41(s,4H)ppm;

[0115] 13 C NMR (DMSO-d6, 100MHz): δ157.9, 147.9ppm.

[0116] From the above structural identification results, it can be seen that the bright red solid obtained in this example is the target product compound TYX-1.

[0117] The physical picture of TYX-1 compound is as follows Figure 1 shown.

[0118] The X-ray single crystal diffraction structure of TYX-1 compound is shown in Figure 2 shown.

[0119] The scanning electron microscopy image of TYX-1 compound is as follows Figure 3 As shown, from Figure 3 It can be seen that the shape and structure of TYX-1 compound are regular.

[0120] Example 2:

[0121] This example provides a method for preparing a nitrogen-rich energetic tetrazine bis-indole skeleton compound, wherein the nitrogen-rich energetic tetrazine bis-indole skeleton compound is compound TYX-2. The method comprises the following steps:

[0122]

[0123] Step 3, preparation of compound TYX-2:

[0124] Step 301 , weigh 1.0 equiv of compound TYX-1, and respectively measure 4.0 equiv of fuming nitric acid (concentration of 98 wt.%) and 5.0 equiv of concentrated H 2 SO 4 (concentration of 70 wt.%).

[0125] Step 302: At 0°C, 5.0 equiv of concentrated H2SO4 is placed in a reaction flask, and then 4.0 equiv of fuming nitric acid is added dropwise to the concentrated H2SO4 under rapid stirring to prepare a nitric-sulfuric acid solution; at 0°C, 1.0 equiv of compound TYX-1 is added in batches to the nitric-sulfuric acid solution.

[0126] Step 303: Add 4.0 equiv of a 50-60% by mass Na2MoO4 solution in H2O2 to the reaction solution of step 302 at 0°C. After the addition, continue stirring for 8.0 hours and monitor the reaction progress using a TLC plate.

[0127] Step 304: After the reaction is completed, 20.0 equiv of crushed ice is poured into the reaction bottle in an ice-water bath, and an orange solid is precipitated. The reaction bottle is then placed in an ice-water bath for 0.5 to 10 hours.

[0128] Step 305: Filter out the orange solid precipitate, and wash it repeatedly with water and ether for 3 to 5 times, respectively, to obtain compound TYX-2.

[0129] Structure identification:

[0130] Elemental analysis: Anal.calcd for C4H4N 10 :C,21.63;H,0.91;N,63.06;Found:C,21.69;H,0.93;N,62.98.

[0131] Infrared spectrum (KBr, cm -1 ):3463, 3353 (-NH2 stretching vibration), 1685, 1625 (-NH2 in-plane deformation vibration), 1567, 1545 (-NO2 symmetric stretching vibration), 1368, 1317, 1533 (-NO2 asymmetric stretching vibration), 916, 846, 763 (CN stretching vibration), 741, 714, 692 (-NH2 out-of-plane deformation vibration).

[0132] 1 H NMR(DMSO-d6,400MHz): δ9.31(s,2H)ppm;

[0133] 13 C NMR (DMSO-d6, 100MHz): δ172.1, 159.9, 152.8, 145.4ppm.

[0134] From the above structural identification results, it can be seen that the bright red solid obtained in this example is the target product compound TYX-2.

[0135] The X-ray single crystal diffraction structure of TYX-2 compound is shown in Figure 4 shown.

[0136] The scanning electron microscopy image of TYX-2 compound is as follows Figure 5 As shown. Figure 5 It can be seen that the TYX-2 compound has a graphene-like structure.

[0137] Example 3:

[0138] This example provides a method for preparing a nitrogen-rich energetic tetrazine bis-indole skeleton compound, wherein the nitrogen-rich energetic tetrazine bis-indole skeleton compound is compound TYX-3. The method comprises the following steps:

[0139]

[0140] Step 301 is the same as step 301 in embodiment 2.

[0141] Step 302 is the same as step 302 in embodiment 2.

[0142] Step 303: At 0° C., add 4.0 equiv of a 50-60% by mass KMnO 4 solution in H 2 O 2 to the reaction solution of step 303, stir at 90° C. for 8.0-16.0 h, and monitor the reaction progress using a TLC plate.

[0143] Step 304 is the same as step 304 in embodiment 2.

[0144] Step 305 is the same as step 305 in Example 2, and compound TYX-3 can be obtained.

[0145] Structure identification:

[0146] Elemental analysis: Anal.calcd for C4N 10 O4:C,19.06;N,55.56;Found:C,19.14;N,55.48.

[0147] Infrared spectrum (KBr, cm -1 ):1548(ON stretching vibration),1368(ON stretching vibration),1165(CN symmetric stretching vibration).

[0148] 13 C NMR (DMSO-d6, 100MHz): δ168.3, 143.6ppm.

[0149] From the above structural identification results, it can be seen that the bright red solid obtained in this example is the target product compound TYX-3.

[0150] Example 4:

[0151] This example provides a method for preparing a nitrogen-rich energetic tetrazine bis-indole skeleton compound, wherein the nitrogen-rich energetic tetrazine bis-indole skeleton compound is compound TYX-4. The method comprises the following steps:

[0152]

[0153] Step 301: weigh 4.0 equiv of concentrated nitric acid (concentration: 68 wt.%) and place it in a reaction bottle at 0-5°C.

[0154] Step 302 , weigh 1.0 equiv of compound TYX-1, and add the compound TYX-1 into concentrated nitric acid solution in batches.

[0155] Step 303: After the addition of compound TYX-1 is completed, the reaction solution is stirred at 15-25° C. for 12-24 hours, and the reaction progress is monitored using a TLC plate.

[0156] Step 304: After the reaction is completed, the reaction solution is poured into an ice-water bath, the resulting precipitate is filtered out, and the resulting solid is repeatedly washed 3 to 5 times with 1.0 to 100.0 equiv of anhydrous ethanol, methanol, or acetone.

[0157] Step 305 , the obtained solid is placed in a tray and placed in a vacuum drying oven at 50-60° C. for drying for 6.0-20.0 hours to obtain a light yellow solid, namely compound TYX-4.

[0158] Structure identification:

[0159] Elemental analysis: Anal.calcd for C4N 10 O4:C,20.26;H,1.28;N,64.97;Found:C,20.30;H,1.19;N,64.92.

[0160] Infrared spectrum (KBr, cm -1):3317, 3251 (-NH2 stretching vibration), 3171 (-NH2 stretching vibration), 1673, 1623 (-NH2, in-plane deformation vibration), 1556, 1503 (-NO2 symmetric stretching vibration), 1356, 1302 (-NO2 asymmetric stretching vibration), 920, 887 (CN stretching vibration), 696 (-NH2 out-of-plane deformation vibration).

[0161] 1 H NMR(DMSO-d6,400MHz): δ8.46(s,3H)ppm;

[0162] 13 C NMR (DMSO-d6, 100MHz): δ170.9, 156.5, 150.3, 145.0ppm.

[0163] From the above structural identification results, it can be seen that the bright red solid obtained in this example is the target product compound TYX-4.

[0164] Example 5:

[0165] This example provides a method for preparing a nitrogen-rich energetic tetrazine bis-indole skeleton compound, wherein the nitrogen-rich energetic tetrazine bis-indole skeleton compound is compound TYX-5. The method comprises the following steps:

[0166]

[0167] Step 301: weigh 4.0 equiv of concentrated nitric acid (concentration: 68 wt.%) and place it in a reaction bottle at 0-5°C.

[0168] Step 302 , weigh 1.0 equiv of compound TYX-1, and add the compound TYX-1 into concentrated nitric acid solution in batches.

[0169] Step 303, after the addition of compound TYX-1 is completed, the reaction solution is stirred at 0-5°C for 0.5-3.0 hours; after the reaction solution stabilizes, it is stirred at room temperature for 1.0-6.0 hours, and then stirred at 50-80°C for 4.0-12.0 hours, and the reaction progress is monitored by TLC plate.

[0170] Step 304: After the reaction is completed, the reaction solution is poured into an ice-water bath, the resulting precipitate is filtered out, and the resulting solid precipitate is repeatedly washed 3 to 5 times with 10.0 equiv of anhydrous ethanol, methanol, or acetone.

[0171] Step 305 , the obtained solid precipitate is placed in a tray and placed in a vacuum drying oven at 50-60° C. for drying for 6.0-20.0 hours to obtain a light yellow solid, namely compound TYX-5.

[0172] Structure identification:

[0173] Elemental analysis: Anal.calcd for C4N 10 O4:C,17.03;H,0.71;N,59.57;Found:C,17.33;H,0.72;N,59.26.

[0174] Infrared spectrum (KBr, cm -1 ):3132, 3116 (-NH stretching vibration), 1626, 1602 (-NH2 in-plane deformation vibration), 1571, 1512 (-NO2 symmetric stretching vibration), 1365, 1322 (-NO2 asymmetric stretching vibration), 988, 914 (CN stretching vibration), 624 (-NH2 out-of-plane deformation vibration).

[0175] 1 H NMR(DMSO-d6,400MHz): δ10.77(s,2H)ppm;

[0176] 13 C NMR (DMSO-d6, 100MHz): δ163.2, 148.0ppm.

[0177] From the above structural identification results, it can be seen that the bright red solid obtained in this example is the target product compound TYX-5.

[0178] Performance testing:

[0179] First, thermal performance test:

[0180] The DSC thermal decomposition diagrams of compounds TYX-1 to TYX-5 in Examples 1 to 5 are as follows: Figures 6 to 10 The DSC data were obtained in a nitrogen environment with a heating rate of 10°C / min. Figures 6 to 10 It can be seen that TYX-1 has the highest thermal decomposition peak temperature, which is as high as 473.2℃.

[0181] Second, thermal behavior test of compound TYX-1:

[0182] like Figure 11 As shown in the figure, the ultra-high temperature heat-resistant energetic material skeleton compound TYX-1 was selected and the thermal behavior of compound TYX-1 was studied by non-isothermal DSC. -1 , 5K min -1 、10K·min -1 and 20K·min -1The decomposition peak temperatures at the heating rate of 400 nm were 453.6°C, 463.7°C, 473.2°C and 482.9°C respectively.

[0183] Third, the kinetic performance test of compound TYX-1:

[0184] The kinetic parameters of compound TYX-1 were calculated by the Kissinger method, the Friedman method and the combined kinetic method, and the results are listed in Table 1. As can be seen from Table 1, the activation energies calculated by the Kissinger method, the Friedman method and the combined kinetic method are 311.69 kJ·mol -1 、279.63kJ·mol -1 and 287.04 kJ·mol -1 Generally, a higher activation energy means that more energy is required to reach the activation energy barrier, resulting in a slower start of the decomposition reaction. A review of the literature revealed that the activation energy of DAP-4, an explosive with excellent heat resistance, is 205.4 kJ·mol -1 , and the activation energy of the material of the present invention is much higher than that of DAP-4 explosive.

[0185] In the present invention, DAP-4 refers to a compound having a molecular formula (C6H 14 For example, the compound (C6H 14 N2)[NH4(ClO4)3].

[0186] Table 1 Kinetic parameters calculated by Kissinger method, Friedman method and combined kinetic method

[0187]

[0188] To obtain more accurate calculation results, the Fraser-Suzuki equation was used to fit the DSC decomposition exothermic peaks of the raw data from the Friedman method. The results showed that all correlation coefficients were greater than 0.99, meeting the accuracy requirements for kinetic evaluation.

[0189] Fourth, the thermal decomposition kinetic parameter calculation performance test of compound TYX-1:

[0190] Figure 12 The α-T curve of the conversion rate α of TYX-1 changing with temperature, Figure 13 The Ea-α curve of TYX-1 was calculated by the Friedman method. Figure 12 and Figure 13It can be seen that the activation energy of the TYX-1 material of the present invention is much higher than that of the DAP-4 explosive.

[0191] Fifth, sensitivity performance test:

[0192] According to GJB772A-97, the impact probability of explosion (PI) (10 kg drop weight, 25 cm drop height), characteristic drop height (H50) (5 kg drop weight), and friction probability of explosion (PF) (3.92 MPa gauge pressure, 90° swing angle) were measured using a WL-1 explosive impact sensitivity meter and a WM-1 explosive friction sensitivity meter, respectively. The impact and friction sensitivity data for the seven compounds are shown in Table 2.

[0193] Table 2 Impact sensitivity and friction sensitivity data of seven compounds

[0194] Compound name Impact sensitivity (IS / J) Friction sensitivity (FS / N) TYX-1 >40 >360 TYX-2 >40 >360 TYX-3 18 200 TYX-4 10 280 TYX-5 6 190

[0195] As can be seen from Table 2, the nitrogen-rich energetic tetrazine bisinium salt skeleton compound has the highest impact sensitivity >40J and the highest friction sensitivity >360N.

[0196] Sixth, detonation performance prediction:

[0197] The explosion equation of compound TYX-1 is: C4H4N 10 →4C+2H2+5N2.

[0198] The explosion equation of compound TYX-2 is: C4H2N 10 O2→3C+H2O+CO+5N2.

[0199] The explosion equation of compound TYX-3 is: C4N 10 O4→4C+2CO2+5N2.

[0200] The explosion equation of compound TYX-4 is: C4H3N 11 O2→3C+H2O+CO+1 / 3NH3+20 / 3N2.

[0201] The explosion equation of compound TYX-5 is: C4H2N 12 O4→5 / 2C+H2O+3 / 2CO2+6N2.

[0202] In order to study the detonation performance of the nitrogen-rich energetic tetrazine bisinium salt skeleton compound synthesized in the present invention, theoretical calculations were carried out. The approximate explosion equation of the target complex was determined based on the H2O-CO2 (Aiaa Journal, 2015, 12(1):9-10) theory, and the detonation velocity and pressure were calculated in combination with the Kamlet-Jacobs equation.

[0203] The Kamlet-Jacobs formula is:

[0204] D=1.01Φ 1 / 2 (1+1.30ρ).

[0205] P=1.558Φρ 2 .

[0206] Φ=31.68N(MQ) 1 / 2 .

[0207] Where D is the detonation velocity, P is the detonation pressure, ρ is the density, N is the number of moles of gas explosion products, M is the average molecular mass of gas explosion products, and Q is the detonation heat.

[0208] The detonation performance parameters of seven compounds and their common explosives were calculated using the Kamlet-Jacobs formula. The results are shown in Table 3.

[0209] Table 3 Detonation performance parameters of seven compounds and their common explosives

[0210] Compound Density (g / cm3) -3 )]> <![CDATA[爆速(ms -1 )]]> Explosion pressure (GPa) TYX-1 1.83 8304 32.8 TYX-2 1.98 8998 38.2 TYX-3 2.02 9470 46.8 TYX-4 1.87 8890 36.1 TYX-5 1.96 9398 43.3 TNT 1.65 6881 19.5 TATB 1.94 7867 29.1 HNS 1.73 7170 21.8 TACOT 1.83 7200 24.5 LLM-105 1.77 8529 31.4 TNBP 1.82 8017 28.2 RDX 1.82 8977 35.2

[0211] In Table 3, TNT is 2,4,6-trinitrotoluene; TATB is triaminotrinitrobenzene; HNS is hexanitroquinone; TACOT is tetranitrodiphenyltetrazoline; LLM-105 is 2,6-diamino-3,5-dinitropyrazine-1-oxide; TNBP is 4,8-dipicrylbisfuroxanopyrazine; and RDX is hexogen, i.e., 1,3,5-trinitro-1,3,5-triazacyclohexane.

[0212] As can be seen from Table 3, compound TYX-3 has the highest detonation velocity and the largest detonation pressure, with a detonation velocity of 9470 m / s and a detonation pressure of 46.8 GPa.

[0213] Seventh, slow-baking heat resistance test of compound TYX-2:

[0214] The sample for slow-baking heat resistance test is composed of 95% TYX-2 elemental explosive and 5% high-temperature resistant binder fluororubber. The sample size is 20×30mm, the molding pressure is 2500, and the test temperature range is 30~350℃. Figure 14 shown.

[0215] The test process of slow baking heat resistance test is:

[0216] (a) Open the end cover on one side of the bomb body and place the weighed sample into the slow-baking bomb.

[0217] (b) Install the temperature sensor on the projectile.

[0218] (c) Install the heating jacket outside the projectile.

[0219] (d) Connect the heating power line and the temperature measuring line.

[0220] (e) Turn on the main power of the temperature control box and set the temperature control program on the computer; increase the temperature to 200°C at 3°C / min and increase the temperature to 350°C at 1°C / min.

[0221] (f) The decomposition temperature and reaction intensity of the sample shall be recorded throughout the test. If an explosion reaction occurs during the test, the test shall be terminated.

[0222] The appearance of the sample in the slow baking heat resistance test after slow baking at 350℃ for 60.0h is shown in the figure below. Figure 15 As shown, from Figure 15 It can be seen that no combustion or explosion reaction occurred during the test, indicating that the sample of compound TYX-2 can withstand 60.0h or more under 350℃ slow baking conditions and has excellent slow baking heat resistance.

Claims

1. A nitrogen-rich energetic tetrazine bisinium salt skeleton compound, characterized in that: The structural formula of the compound is: ； Where: R1 is -NH2, -NO2 or -NHNO2; R2 is -NH2, -NO2 or -NHNO2.

2. The nitrogen-rich energetic tetrazine bisinium salt skeleton compound according to claim 1, wherein The nitrogen-rich and energetic tetrazine bisinium salt skeleton compound is compound TYX-1, compound TYX-2, compound TYX-3, compound TYX-4 or compound TYX-5; The structural formula of the compound TYX-1 is ; The structural formula of the compound TYX-2 is ; The structural formula of the compound TYX-3 is ; The structural formula of the compound TYX-4 is ; The structural formula of the compound TYX-5 is .

3. The nitrogen-rich energetic tetrazine bisinium salt skeleton compound according to claim 2, wherein: The thermal decomposition peak temperature of the compound TYX-1 is as high as 473.2°C.

4. The nitrogen-rich energetic tetrazine bisinium salt skeleton compound according to claim 2, wherein The detonation velocity of the compound TYX-3 is 9470 m / s.

5. The nitrogen-rich energetic tetrazine bisinium salt skeleton compound according to claim 2, wherein: The explosion pressure of the compound TYX-3 is 46.8 GPa.

6. The nitrogen-rich energetic tetrazine bisinium salt skeleton compound according to claim 2, wherein: The impact sensitivity of the compound TYX-1 and the compound TYX-2 is greater than 40J, and the friction sensitivity is greater than 360N.

7. A method for preparing the nitrogen-rich energetic tetrazine bisinium salt skeleton compound according to claim 2, characterized in that: The method comprises the following steps: Step 1: Compound 1 and 5-aminotetrazole are used as raw materials, sulfolane is added, and the mixture is heated to 100-150° C. for reaction. After the reaction, the mixture is separated and purified to obtain compound 2; The structural formula of the compound 1 is: ； The structural formula of the compound 2 is: ； Step 2: Compound 2 is added to polyphosphoric acid in batches, reacted at a temperature of 150-220° C., and after the reaction, the compound TYX-1 is obtained by separation and purification.

8. The method for preparing the nitrogen-rich energetic tetrazine bisinium salt skeleton compound according to claim 7, wherein: The method further comprises step three; The step three comprises the following steps: Compound TYX-1 was used as the raw material to react in fuming nitric acid, concentrated H2SO4 and Na2MoO4 H2O2 solution at 0°C to obtain compound TYX-2. Alternatively, compound TYX-1 is used as a raw material to react in fuming nitric acid, concentrated H2SO4, and KMnO4 in H2O2 solution at 0°C to obtain compound TYX-3; Alternatively, compound TYX-1 is used as a raw material and reacted in concentrated nitric acid at 15-25°C to obtain compound TYX-4; Alternatively, compound TYX-1 is used as a raw material, and the reaction solution is stirred at 0-5°C for 0.5-3.0 h in concentrated nitric acid; after the reaction solution stabilizes, it is stirred at room temperature for 1.0-6.0 h, and then stirred at 50-80°C for 4.0-12.0 h to react to obtain compound TYX-5.

9. The method for preparing the nitrogen-rich energetic tetrazine bisinium salt skeleton compound according to claim 7, wherein: The specific process of step one includes the following steps: Step 101, weighing compound 1 and 5-aminotetrazole and adding them to a reaction flask, and simultaneously weighing sulfolane and adding them; Step 102, heating the reaction solution in step 101 to 100-150° C. and reacting for 18-30 hours; Step 103: After the reaction is completed, the reaction solution is cooled to 50-80° C., and a high-boiling-point, highly polar solvent is added to dilute the reaction solution. A reddish-brown solid is observed to precipitate in the reaction solution. Step 104, filtering out the reddish-brown solid powder and washing the reddish-brown solid powder; Step 105, drying the obtained reddish-brown solid powder to obtain a completely dried reddish-brown solid crude product; Step 106, placing the completely dried reddish-brown solid crude product in a high-boiling-point, highly polar solvent under reflux, cooling, filtering, washing, and drying to obtain an orange-yellow solid compound 2; The specific process of step 2 includes the following steps: Step 201, weighing compound 2 and polyphosphoric acid; Step 202, adding compound 2 to polyphosphoric acid in batches at 100-165° C. with stirring to form a reaction solution; Step 203, heating the reaction solution to 150-220° C. and reacting at this temperature for 3.0-10.0 hours; Step 204: After the reaction is completed, the resulting mixture is cooled to 60-70° C., and distilled water is added to dilute the mixture. A yellow solid powder is precipitated, and the mixture is left at room temperature for 6.0-24.0 hours. Step 205: Filter out the yellow solid precipitate, and wash it repeatedly with water and methanol for 3 to 5 times; Step 206: Dry the obtained yellow solid precipitate to obtain a bright red solid, which is compound TYX-1.

10. The method for preparing the nitrogen-rich energetic tetrazine bisinium salt skeleton compound according to claim 9, wherein: In step 1, the high boiling point and high polarity solvent is N , N -dimethylformamide, dimethyl sulfoxide or nitrogen methyl pyrrolidone.

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