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The deuterium isotope effect was applied to condensed-phase thermodinamical reactions of HMX and HMX-d8 by using isothermal techniques.Dissimilar deuterium isotope effects revealed a mechanistic dependence of HMX upon different physical states which may singularly predominate in a specific type of thermal event.Solid-state HMX thermodinamical decomposition produces a primary deuterium isotope effect (DIE), indicating that covalent C-H bond rupture is the rate-controlling step in this phase.An apparent inverse DIE is displayed by the mixed melt phase and can be attributed to C-H bond contraction during a weakening of molecular lattice forces as the solid HMX liquefies.The liquid-state decomposition rate appears to be controlled by ring C-N bond cleavage as evidenced by a secondary DIE and higher molecular weight products.These results reveal a dependence of the HMX decomposition process on physical state and lead to a broader mechanistic interpretation which explains the seemingly contradictory data found in current literature reviews.

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The solubility of 3,7-dinitro-1,3,5,7-tetraazabicyclo [3.3.1] nonane (DPT) was measured in ethanenitrile, methanol, 1,1-dichloroethane, dimethyl sulfoxide (DMSO), acetone, ethyl acetate, ethyl acetate and methanol mixture, and acetonitrile and water mixture from 288.15 K to 308.15 K. In this paper, the determination method of DPT was first established by high-performance liquid chromatography (HPLC) with optimized chromatographic conditions. The solubility of DPT in all solvents was measured upon this chromatographic method. Experimental results show that the order of solubility can be represented as DMSO > acetonitrile > ethyl acetate > ethyl acetate/methanol (9:1, v/v) > ethyl acetate/methanol (7:3, v/v) > acetone > acetonitrile/water (9:1, v/v) > ethyl acetate/methanol (5:5, v/v) > acetonitrile/water (7:3, v/v) > 1,1 - dichloroethane > methanol. Moreover, its solubility increased with raising the temperature. The thermodynamic properties of DPT, such as solution enthalpy, have also been calculated.

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A novel and efficient approach for the synthesis of octahydro- 1, 3, 5, 7-tetranitro-1, 3, 5, 7- tetrazocine (HMX) was achieved through nitrolysis of 1, 3, 5, 7-tetracetyl-1, 3, 5, 7-tetraazacyclooctane (TAT) in the presence of red fuming nitric acid (RFNA) and P2O5. various parameters such as temperature, concentration of nitrating agent, time and mole ratio of RFNA/P2O5 has been investigated to develop the optimum conditions. The good yields, high purities, easy work-up and short reaction times are advantages of this method.

New process to synthesize HMX from 3,7-dinitro-1,3,5,7- tetraazabicyclo[3,3,1]nonane (DPT) using ultrasound in ionic liquid was developed. The reaction has been carried out in ultrasonic bath and the effect of various parameters such as presence and absence of ultrasound, volume and type of solvent, temperature, concentration of nitrating agent has been investigated with the aim of obtaining the optimum conditions for the synthesis of HMX. It was observed that yield was significantly enhanced from 42.3% up to 87.4% through the ultrasonically promoted nitrolysis of DPT to HMX at ambient condition.

Detailed and global models are presented for thermodynamically inhibited nucleation-growth reactions and applied to the ?2-?? phase transition of HMX (nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine). The detailed model contains separate kinetic parameters for the nucleation process, including an activation energy distribution resulting from a distribution of defect energies, and for movement of the resulting reaction interface within a single particle. A thermodynamic inhibition term is added to both processes so that the rates go to zero at the transition temperature. The global model adds the thermodynamic inhibition term to the extended Prout - Tompkins nucleation-growth formalism for single particles or powders. Model parameters are calibrated from differential scanning calorimetry data. The activation energy for nucleation (333 kJ/mol) is substantially higher than that for growth (29.3 kJ/mol). Use of a small activation energy distribution (a??400 J/mol) for the defects improves the fit to a powered sample for both the early and late stages of the transition. The effective overall activation energy for the global model (208.8 kJ/mol) is between that of nucleation and growth. Comparison of the two models with experiment indicates the thermodynamic inhibition term is more important than the energy distribution feature for this transition. On the basis of the applicability of the Prout-Tompkins kinetics approach to a wide range of organic and inorganic materials, both models should have equally broad applicability for thermodynamically constrained reactions.

The invention discloses a method for directly preparing beta-HMX with different particle sizes. The method comprises the following steps of: carrying out nitration reaction on 1-nitroso-3, 5, 7-trinitro-1, 3, 5, 7-tetraazacyclooctane (MNX) and fuming nitric acid at room temperature; slowly dropwise adding dilute nitric acid and water in two stages for crystallization, filtering, washing and dryingto obtain beta-HMX with different particle sizes. The product obtained by the method is high in purity, and the yield reaches 92.2%; and the use of procedures such as oxidative crystallization or recrystallization is avoided, the production process is simplified, the production cost is reduced, the environmental pollution is reduced, and the production safety is improved.

The problem how ammonium nitrate affects the nitrolysis of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3.3.1]nonane (DPT) in nitric acid to prepare 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) has puzzled chemists for decades. In this paper, experimental work and theoretical calculation are described to investigate the long-standing challenge. The experiment results showed that ammonium nitrate or alkylammonium chlorides were in favor of the formation of 1-nitroso-3,5,7-trinitro-1,3,5,7-tetraazacyclooctane (MNX) but hindered the conversion of MNX to HMX. A plausible catalytic mechanism was proposed. In which ammonia or amines, in situ generated from the unfavorable balance with their salts, act as Lewis base catalysts. At the same time, the DFT computation results reveal that rigid bicyclic transition states established with 1-hydroxymethyl-3,5,7-trinitro-1,3,5,7-tetraazacyclooctane, ammonia (or amines) and three water molecules lead to very low activation energies. Then, a novel process for the preparation of MNX with excellent yield up to 78.5% was developed, which is free of the use of NaNO2 or N2O4 as nitroso resources.

The invention discloses a preparation method of HMX. The preparation method comprises the steps of dissolving dinitrogen pentoxide into an organic solvent to form a nitrating agent; slowly adding ammonium salt into the nitrating agent, and adding DPT in batches to obtain reactants; controlling the temperature of the materials to be 0-10 DEG C in a feeding process, heating the reactants up to 20-35 DEG C, and carrying out a reaction at the constant temperature for 20-60min; after the reaction is finished, carrying out solid-liquid separation to obtain solid; washing the obtained solid, drying in the air, and purifying to obtain the HMX, wherein the organic solvent is selected from acetonitrile and dichloromethane, and the ammonium salt is selected from tetramethyl ammonium chloride, ammonium carbonate, ammonium acetate and ammonium oxalate. The preparation method provided by the invention is mild in reaction conditions and easy in separation of products, and needs a less amount of acid; the system does not produce waste acid, thus being low in treatment cost; furthermore, the preparation method greatly increases the yield of the HMX.

Direct nitrolysis of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3,3,1]nonane (DPT) is a feasible way to synthesize HMX, which is one of the most powerful explosives. A new nitrolysis process involving the use of nitric acid and various solid acid catalysts such as silica sulfuric acid, heteropoly acids, and metal nitrates was used as an effective and safe nitrating agents for the nitration of DPT to HMX under mild and heterogeneous conditions with good yields. In order to optimize the process, the reactions were carried out with a varying amount of catalysts and also the catalysts were efficiently recovered.

1,5-Diacetyl-3,7-dinitro-l,3,5,7-tetraazacyclooctane (DADN) is a key intermediate in the preparation of octahydro- 1,3,5,7-tetranitro-1,3,5,7- tetrazocine (HMX), one of the most powerful high-melting explosives. The present investigation focuses on nitrolysis of DADN to HMX by developing a new nitrolysis process involving the use of nitric acid catalyzed by Silica Sulfuric Acid (SSA). In order to optimize the process parameters for synthesis of HMX to obtain higher yield and purity, a study was carried out with variation of some parametric conditions like time, mole ratio of SSA and nitric. This method gave us green and mild conditions for nitration reaction.

Direct nitrolysis of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3,3,1]nonane (DPT) is a feasible way to synthesize HMX, and it has multiple practical applications. In this paper, a new nitrolysis process involving the use of an N2O5-HNO3 system catalyzed by acidic ionic liquids (AILs) was developed. The results show that [Et3NH]TsO was the best catalyst among the 28 AILs used and that HMX was formed at a higher yield of 61%, compared to 45% without any AIL. Moreover, with the addition of N2O5, the yield was further increased to a maximum value of 69%. The AILs were also efficiently recovered by simple extractions without any apparent loss of catalytic activity, even after five runs.

The effect of metallic ions on the nitrolysis of DAPT [3,7-diacetyl-1,3,5, 7-tetraazabicyclo(3.3.1)nonane] and HA (hexamine) was investigated by experimental and theoretical approaches. The combinatorial reagent, M(NO -3)n/Ac2/NH4NO 3 (M=Mg2+, Cu2+, Pb2+, Bi 3+, Fe3+ and Zr4+), was found to be efficient in the experiment of the nitrolysis of DAPT. A key intermediate during the nitrolysis of DAPT was detected by 1H NMR. The formation mechanism of the intermediate was proposed and analyzed. Some discrepant results for the nitrolysis of DAPT and HA catalyzed by different metallic nitrates were explained based on hard-soft and acid-base principle and stabilized energy of ion-complex. From the latter point of view, some cations with high polarizable ligands, e.g., OSO2CF3-, (CF3SO 2)2N-, and (C4F9SO 2)2N-, can increase the yields. Two newly designed catalysts, Cu[(CF3SO2)2N]2 and Cu[(C4F9SO2)2N]2, were tested to be highly efficient. Copyright

Potassium amidosulfate reacts with formaldehyde at pH 7-12 to afford a mixture of dipotassium 4-hydroxy-1,3-diazabutane-1,3-disulfonate hydrate and tripotassium 6-hydroxy-1,3,5-triazahexane-1,3,5-trisulfonate HO(CH2NSO3K)n·H2O (n = 2, 3). The reaction of the same compounds at pH 1-3 gives diammonium 1,3,5,7-tetraazabicyclo[3.3.1]nonane-3,7-disulfonic acid sulfate dihydrate.

The 14C-uniformly labeled (UL) explosive, octahydro-1,3,5,7- tetranitro-1,3,5,7-tetrazocine (HMX) was synthesized in 40% yield by nitrolysis of 14C-labeled hexamethylenetetramine (hexamine) in the presence of boron trifluoride diethyl etherate as catalyst. The labeled hexamine was synthesized in 77% yield from 14C-labeled formaldehyde and ammonium hydroxide. The specific activity of 14C-labeled HMX was 0.24 mCi/mmol, a total of 58 μCi was prepared. The radiochemical purity of the labeled substance was 95% by HPLC-Liquid scintillation counting and 98% by HPLC-UV at 232 nm.

1,3,5,7-TETRANITRO-1,3,5,7-TETRAAZACYLOOCTANE IS PREPARED BY NITROLYSIS OF A 1,3,5,7-TETRAACYL-1,3,5,7-TETRAAZACYLOOCTANE OR A 1,5-DIACYL-3,7-DINITRO11,3,5,7-TETRAAZACYCLOOCATNE WITH NITROGEN PENTOXIDE.