Synthesis method of 1, 1 '-diamino-5, 5'-bistetrazole metal complex

Abstract

The invention discloses a synthesis method of a 1, 1 '-diamino-5, 5'-bistetrazole metal complex, which specifically comprises the following steps: step 1, dissolving a certain amount of dioxocarbonyl-1, 1 '-diamino-5, 5'-bistetrazole in a certain amount of solvent, and heating to a certain temperature; step 2, dissolving corresponding metal salt in water, and adding into the solution obtained in the step 1; 3, standing the solution obtained in the step 2 to separate out a solid; and 4, putting the solid obtained in the step 3 into water, and recrystallizing to obtain the 1, 1 '-diamino-5, 5'-bistetrazole metal complex. In the first step, the solvent comprises one or more of water, methanol, ethanol, acetone, acetonitrile and dimethyl sulfoxide.

Description

Technical Field

[0001] This invention relates to the field of organic energetic materials, and more particularly to a method for synthesizing a 1,1′-diamino-5,5′-bitetrazole metal complex. Background Technology

[0002] Energetic compounds are important materials in the field of national defense and security. Generally speaking, the higher the nitrogen content in a material, the greater the energy released by the molecules during the reaction. Tetraazole compounds are aromatic planar cyclic structures with high positive heat of formation, good stability, and low sensitivity, making them a hot research topic in the field of high-nitrogen energetic materials. 1,1′-diamino-5,5′-bitetraazole (1,1′-DABT), formed by introducing amino groups at the 1 and 1′ positions of 5,5′-bitetraazole (H2BT), has an even higher nitrogen content, generating more heat and nitrogen during decomposition. Simultaneously, the introduction of the amino group weakens the acidity of the H2BT structure, making it neutral or weakly basic, reducing its corrosiveness to metal casings during storage, and enhancing its stability and water solubility.

[0003] Compared to the pure bitetrazole framework, introducing metal complexes into its structure further improves the properties of the compounds. Fischer et al. reacted sodium cyanide with sodium azide and manganese dioxide under acidic conditions to obtain manganese salts of H2BT, and prepared corresponding high-nitrogen energetic ionic salts such as guanidine, aminoguanidine, diaminoguanidine, triaminoguanidine, and carbazide salts. Among them, H2BT showed reduced salt sensitivity and belonged to high-energy insensitive energetic materials. In 2011, Thomas M. Klapötke reported the synthesis of alkaline earth metal complexes of H2BT in "Alkaline Earth Metal Salts of 5,5-Bistetrazole – from Academical Interest to Practical Application", 2011, 637, 1693–1701, and investigated the application of the complexes as coloring pyrotechnic components. In 2012, Thomas M. Klapötke reported the synthesis of copper complexes of H2BT in "Preparation and Crystal Structure of Diaqua(μ-5,5'-bistetrazolato-κ4N1,N2,N5,N6)copper(II)", 2012, 2, 958-966, and investigated its thermal stability and stability against impact, friction, and electric sparks. Patent CN105440070A, "1,1'-Dihydro-5,5'-Bistetrazole-Lead Coordination Polymer and its Preparation Method", disclosed the synthesis of lead coordination polymers of H2BT and investigated their thermal stability. In 2016, Tonglai Zhang, in "Synthesis, structure and characterization of neutral coordination polymers of 5,5'-bistetrazole with copper(II), zinc(II) and cadmium(II): a new route to reconcile oxygen balance and nitrogen", reported the synthesis of lead coordination polymers of H2BT and investigated their thermal stability. The synthesis of copper, zinc, and cadmium coordination polymers of H2BT was reported in "Content of High-Energy MOFs", 2016, 45, 16779-16783, and it was pointed out that materials with different impact and friction sensitivities can be obtained by coordinating different metals.

[0004] The patent CN1761637A, titled "Gas Generator," discloses a method for generating a complex by co-complexing copper ions with tetrazolium and ethylenediamine, using amino groups as a strong complexing agent. The synthesis is shown below: Current research mainly focuses on the preparation of bitetrazole metal complexes. Only one example uses ethylenediamine as a coordination aid for complexation. The amino group in 1,1′-dihydroxy-5,5′-bitetrazole has a similar complexing effect to ethylenediamine. Using 1,1′-dihydroxy-5,5′-bitetrazole as a ligand can yield novel nitrogen-rich energetic complexes. Summary of the Invention

[0005] To address the above problems, this invention provides a method for synthesizing 1,1′-diamino-5,5′-bitetrazole metal complexes, specifically comprising the following steps: Step 1: Dissolve a certain amount of dioxycarbonyl-1,1′-diamino-5,5′-bistetrazole in a certain amount of solvent and heat to a certain temperature; Step 2: Dissolve the corresponding metal salt in water and add it to the solution obtained in Step 1; Step 3: Allow the solution obtained in Step 2 to stand and allow solids to precipitate. Step 4: Recrystallize the solid from Step 3 in water to obtain the 1,1′-diamino-5,5′-bitetrazolium metal complex.

[0006] Specifically, in step one, the solvent includes one or more of water, methanol, ethanol, acetone, acetonitrile, and dimethyl sulfoxide.

[0007] Specifically, in step one, the solvent is heated to a temperature of 50-100℃.

[0008] Specifically, the metal salts used in step two contain both main group metals and transition metals.

[0009] Specifically, in step three, the settling time for the solid to precipitate from the solution is 6-72 hours.

[0010] The invention offers the following advantages: The synthesis method of this invention is a direct reaction, employing a one-step synthesis: by directly reacting 1,1′-DABT with a metal salt in a solvent, the traditional ligand pretreatment step is eliminated, shortening the production cycle. No pretreatment is required. The selected reagents are free of high-risk reagents, ensuring safe operation. The solvents are universally applicable: common solvents such as water, methanol, and ethanol can be used, reducing raw material costs and operational complexity. The metal compatibility is broad, compatible with main group metals (such as magnesium and lead) and transition metals (such as copper, manganese, and cadmium), allowing for metal selection to control product properties. Recrystallization provides one-step purification, achieving a purity >95%. Detailed Implementation

[0011] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0012] The following provides a detailed description of the implementation method of the present invention. The description only covers some embodiments and not all embodiments. For clarity, representations and descriptions unrelated to the present invention are omitted in the description.

[0013] To provide a clearer understanding of the technical features, objectives, and beneficial effects of this invention, the following detailed description of the technical solution is provided. Obviously, the described embodiments are only a portion of the embodiments of this invention, not all of them, and should not be construed as limiting the scope of implementation of this invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention.

[0014] A synthetic method for a 1,1′-diamino-5,5′-bitetrazole metal complex is described below: .

[0015] The specific steps are as follows: Step 1: Dissolve a certain amount of dioxycarbonyl-1,1′-diamino-5,5′-bistetrazole in a certain amount of solvent and heat to 50-100℃. Step 2: Dissolve the metal salt in water to prepare an aqueous solution, and add it to the solution obtained in Step 1; Step 3: Allow the solution obtained in Step 2 to stand and allow solids to precipitate. Step 4: Recrystallize the solid from Step 3 in water to obtain the copper complex of 1,1′-diamino-5,5′-bitetraazole.

[0016] Preferably, in step one, the solvent includes one or more of water, methanol, ethanol, acetone, acetonitrile, and dimethyl sulfoxide, with water being the most preferred.

[0017] Preferably, in step two, the metal salt includes, but is not limited to, sulfates, bisulfates, hydrochlorides, nitrates, acetates, formates, trifluoromethanesulfonates, trifluoroacetates, carbonates, basic carbonates, bicarbonates, oxalates, etc., with sulfates being the most preferred.

[0018] Preferably, the settling time for the solid to precipitate from the solution in step three is 6-72 hours.

[0019] Experimental Example 1 0.5 g of dioxocarbonyl-1,1′-diamino-5,5′-bis(tetrazole) was dissolved in 5.5 mL of aqueous solution and heated to 90 °C. Copper nitrate was dissolved in 2 mL of water and added to the above solution. The mixture was allowed to stand at 40 °C for 2 days. After filtration, the resulting solid was recrystallized with water to give the 1,1′-diamino-5,5′-bis(tetrazole) copper complex, with a yield of 55%.

[0020] Experimental Example 2 0.5 g of dioxocarbonyl-1,1′-diamino-5,5′-bis(tetrazolium) was dissolved in 4.5 mL of ethanol and heated to 60 °C. Lead nitrate was dissolved in 2 mL of water and added to the above solution. The mixture was allowed to stand at 40 °C for 2 days. After filtration, the resulting solid was recrystallized with water to give the 1,1′-diamino-5,5′-bis(tetrazolium) lead complex, with a yield of 39%.

[0021] Experiment Example 3 0.5 g of dioxocarbonyl-1,1′-diamino-5,5′-bis(tetrazole) was dissolved in 5 mL of acetonitrile and heated to 70 °C. Magnesium nitrate was dissolved in 2 mL of water and added to the above solution. The mixture was allowed to stand at 40 °C for 2 days. After filtration, the resulting solid was recrystallized with water to give the 1,1′-diamino-5,5′-bis(tetrazole) magnesium complex, with a yield of 43%.

[0022] Experiment Example 4 0.5 g of dioxocarbonyl-1,1′-diamino-5,5′-bis(tetrazole) was dissolved in 5 mL of acetonitrile and heated to 70 °C. Manganese nitrate was dissolved in 2 mL of water and added to the above solution. The mixture was allowed to stand at 40 °C for 2 days. After filtration, the resulting solid was recrystallized with water to give the 1,1′-diamino-5,5′-bis(tetrazole) manganese complex, with a yield of 58%.

[0023] Experimental Example 5 0.5 g of dioxocarbonyl-1,1′-diamino-5,5′-bis(tetrazolium) was dissolved in 5 mL of acetonitrile and heated to 70 °C. Cadmium nitrate was dissolved in 2 mL of water and added to the above solution. The mixture was allowed to stand at 40 °C for 2 days. After filtration, the resulting solid was recrystallized with water to give the 1,1′-diamino-5,5′-bis(tetrazolium) cadmium complex, with a yield of 37%.

[0024] The synthetic method proposed in this patent is technically mature, stable, and widely applicable, successfully achieving the efficient construction of 1,1′-diamino-5,5′-bitetrazole metal complexes. Its "one-step method + common solvent + high-purity product" characteristics are significantly superior to traditional multi-step synthesis or high-cost processes, and it has promising prospects for industrial application.

[0025] As shown in Table 1, compared with traditional methods, such as the experiment in CN105440070A, Experiment 2, using the same metal salt lead nitrate, the yield of Example 2 using the method proposed in this patent is close to that of Comparative Example 1. Furthermore, Example 2 has a lower reaction temperature, is energy-efficient and environmentally friendly, and uses ethanol as the reagent, avoiding the use of highly toxic reagents in traditional methods.

[0026] As shown in Table 1, the method proposed in this patent has successfully synthesized complexes of transition metals (copper, manganese, cadmium) and main group metals (lead, magnesium), and has good universality for metal ions.

[0027] As shown in Table 1, the method proposed in this patent can use a variety of common solvents such as water and acetonitrile, reducing dependence on special reagents and improving its environmental friendliness and economy. It requires no inert atmosphere or expensive catalysts, has low equipment requirements, and is suitable for large-scale production.

[0028] As shown in Table 1, the method proposed in this patent uses a gentle static crystallization process, which avoids violent reactions or the formation of byproducts and is highly safe. Table 1 The above description is merely a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the concept described herein through the above teachings or related technologies or knowledge. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be within the protection scope of the appended claims.

Claims

1. A method for synthesizing a 1,1′-diamino-5,5′-bitetrazole metal complex, specifically comprising the following steps: Step 1: Dissolve a certain amount of dioxycarbonyl-1,1′-diamino-5,5′-bistetrazole in a certain amount of solvent and heat to a certain temperature; Step 2: Dissolve the corresponding metal salt in water and add it to the solution obtained in Step 1; Step 3: Allow the solution obtained in Step 2 to stand and allow solids to precipitate. Step 4: Recrystallize the solid from Step 3 in water to obtain the 1,1′-diamino-5,5′-bitetrazolium metal complex.

2. The method for synthesizing a 1,1′-diamino-5,5′-bitetrazole metal complex according to claim 1, characterized in that, In step one, the solvent includes one or more of water, methanol, ethanol, acetone, acetonitrile, and dimethyl sulfoxide.

3. The method for synthesizing a 1,1′-diamino-5,5′-bitetrazole metal complex according to claim 1, characterized in that, In step one, the solvent is heated to a temperature of 50-100℃.

4. The method for synthesizing a 1,1′-diamino-5,5′-bitetrazole metal complex according to claim 1, characterized in that, The metal salts used in step two contain both main group metals and transition metals.

5. The method for synthesizing a 1,1′-diamino-5,5′-bitetrazole metal complex according to claim 1, characterized in that, In step three, the solution is allowed to stand for 6-72 hours to allow the solid to precipitate.

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