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Parrish, Damon A.

Publications and source records attributed to Parrish, Damon A..

Oxadiazole-based Heterocycles as Building Block for Material Property Control: Design, Synthesis, and Characterization of 3,4-Bis(3-(4-nitro-1,2,5-oxadiazol-3-yl)- 1,2,4-oxadiazol-5-yl)-1,2,5-oxadiazole (LLM-210)

This paper presents an approach to novel oxadiazole-based melt-castable energetic material, LLM-210. Used in pour-in process and 3D printing, melt-castable energetic materials (MCEM) must possess required physical and safety properties of industry-standard energetic materials, also a narrow range of melting point between 80-100 °C. Melting point is difficult to accurately predict, therefore, searching for MCEM is challenging. 3,4-Bis(5-(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazol3-yl)-1,2,5-oxadiazole (LLM-205), composed of five-oxadiazole rings allied via carbon-carbon bonds, was selected as new MCEM candidate. The target molecule was synthesized and characterized, showing a density of 1.807g/cm3 ; thermal decomposing temperature at 299 °C; and insensitive to external stimuli, but the melting point of 104 °C was out of the rang. Based on the molecular properties and ab initio calculations, 3,4-bis(3-(4-nitro-1,2,5-oxadiazol-3-yl)-1,2,4-oxadiazol-5-yl)- 1,2,5-oxadiazole (LLM-210), an isomer of LLM-205, was designed and synthesized from a different way. LLM-210 was characterized as MCEM, possessing melting point of 87 °C; density of 1.812 g/cm3 ; and exothermally decomposing temperature at 314 °C; being insensitive to external stimuli. In this study, the relationship of molecular structure to properties of LLM-205 and LLM-210 based on the results of Density Functional Theory (DFT) and X-ray crystallographic analysis is also briefly discussed.

Chemistry - Chemical explosives↗

Synthesis of a new 1,2,4-triazine derived Azidoxime

A 1,2,4-triazine based azidoxime was formed via the substitution of a chloroxime (3) with sodium azide in ethanol. This compound was characterized via single-crystal X-ray diffraction. This material has a calculated density of 1.746 g•cm –1 and is less sensitive to impact, spark, and friction, as compared to PETN and RDX. The dehydrated material has a calculated density of 1.823 g•cm –1 and the detonation pressure and velocity of 4 are calculated to be 29.1 GPa and 8.67 km•s –1 , respectively.

1,2,4-Triazine↗

Polycyclic N-oxides: high performing, low sensitivity energetic materials

For this study, polycyclic N-oxides were developed based on the heterocycles 1,2,4,5-tetrazine and 4H,8H-difurazano[3,4-b:3’,4’-e]pyrazine. The new compounds are energetic and have excellent explosive properties, while maintaining low mechanical sensitivities. Most notably, compound 7 is thermally stable, insensitive, and and has superior detonation properties to the state-of-the-art insensitive high explosive, 1,3,5-triamino-2,4,6-trinitrobenzene.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Multipurpose Energetic Materials by Shuffling Nitro Groups on a 3,3′‐Bipyrazole Moiety

Abstract A family of 3,3′‐bipyrazole‐based energetic compounds having C‐NO 2 /N‐NO 2 functionalities was synthesized by using various nitrating conditions. These nitro derivatives of bipyrazole are significantly more dense and energetic compared to the corresponding nitropyrazole analogues while maintaining the desired thermal stability and sensitivity. Depending on the number and nature of energetic nitro groups (C‐NO 2 /N‐NO 2 ), different classes of energetic materials, such as green primary explosives, high‐performance secondary explosives and heat‐resistant explosives, were obtained. All the compounds were thoroughly characterized by IR, NMR [ 1 H, 13 C{ 1 H}, 15 N], elemental analysis, and differential scanning calorimetry (DSC). Four were also structurally characterized with single‐crystal X‐ray diffraction studies. Heats of formation and detonation performance were calculated using Gaussian 03 and EXPLO5 v6.01 programs, respectively.

Kumar, Dheeraj↗

Effect of counter-ion on packing and crystal density of 5,5′-(3,3′-bi[1,2,4-oxadiazole]-5,5′-diyl)bis(1 H -tetrazol-1-olate) with five different cations

In energetic materials, the crystal density is an important parameter that affects the performance of the material. When making ionic energetic materials, the choice of counter-ion can have detrimental or beneficial effects on the packing, and therefore the density, of the resulting energetic crystal. Presented herein are a series of five ionic energetic crystals, all containing the dianion 5,5′-(3,3′-bi[1,2,4-oxadiazole]-5,5′-diyl)bis(1 H -tetrazol-1-olate), with the following cations: hydrazinium ( 1 ) (2N 2 H 5 + ·C 6 N 12 O 4 2− ), hydroxylammonium ( 2 ) 2NH 4 O + ·C 6 N 12 O 4 2− [Pagoria et al.. (2017). Chem. Heterocycl. Compd , 53 , 760–778; included for comparison], dimethylammonium ( 3 ) (2C 2 H 8 N + ·C 6 N 12 O 4 2− ), 5-amino-1 H -tetrazol-4-ium ( 4 ) (2CH 4 N 5 + ·C 6 N 12 O 4 2− ·4H 2 O), and aminoguanidinium ( 5 ) (2CH 7 N 4 + ·C 6 N 12 O 4 2− ). Both the supramolecular interactions and the sterics of the cation play a role in the density of the resulting crystals, which range from 1.544 to 1.873 Mg m −1 . In 5 , the tetrazolate ring is disordered over two positions [occupancy ratio 0.907 (5):0.093 (5)] due to a 180° rotation in the terminal tetrazole rings.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Simple and Efficient Synthesis of Explosive Cocrystals containing 3,5-Dimethylpyrazol-1-yl-substituted-1,2,4,5-tetrazines

The reaction of 3,4–dinitropyrazole, 5–nitrotetrazole, or 4–nitro–1,2,3–triazole with 1,2,4,5–tetrazines substituted with 3,5–dimethylpyrazolyl (dmp) groups results in energetic cocrystals after 1 minute of reflux and cooling to room temperature in yields of 89–92 %. Hydrogen–bonding between the dmp group to the N–H of the energetic heterocycles are the predominant interaction that stabilizes the new cocrystals. Each cocrystal packs in a different lattice structure and the cocrystals with sheet–like and herring–bone crystal packing orientations are less sensitive than the cocrystal with the interlocked structure. Electrostatic potential mapping helps rationalize why dmp–substituted tetrazines readily form cocrystals, whereas more electron–deficient pyrazolyl tetrazines do not. Furthermore, the calculated energetic performance of the new cocrystals approaches that of 2,4,6–trinitrotoluene (TNT) and importantly, these materials will aid in the rational design of new cocrystalline energetic materials.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Comprehensive End-to-End Design of Novel High Energy Density Materials: I. Synthesis and Characterization of Oxadiazole Based Heterocycles

A methodology to design novel energetic materials by means of a holistic approach that links synthesis, experimental characterization, quantum-chemical modeling, and statistical empirical evaluation is proposed. An analysis of the revealed structure–property–function correlations in the LLM compound series (oxadiazole-based heterocyclic energetics), BNFF, BNFF-1, LLM-172, LLM-191, and LLM-192, led us to predict, obtain, and characterize a new member in the materials family, LLM-200, which exhibits attractive energetic characteristics compared to known conventional high energy density materials. Finally, while the applied strategy convincingly demonstrated feasibility of the end-to-end design of high energy density materials, there are certain limitations in parallel improvements of sensitivity and performance within a single compound.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Crystal structures of the three closely related compounds: bis­­[(1H-tetra­zol-5-yl)meth­yl]nitramide, tri­amino­guanidinium 5-({[(1H-tetra­zol-5-yl)meth­yl](nitro)­amino}­meth­yl)tetra­zol-1-ide, and di­ammonium bis­­[(tetra­zol-1-id-5-yl)meth­yl]nitramide monohydrate

In the mol­ecule of neutral bis­[(1H-tetra­zol-5-yl)meth­yl]nitramide, (I), C 4 H 6 N 10 O 2 , there are two intra­molecular N—H∙∙∙O hydrogen bonds. In the crystal, N—H∙∙∙N hydrogen bonds link mol­ecules, forming a two-dimensional network parallel to (-201) and weak C—H∙∙∙O, C—H∙∙∙N hydrogen bonds, and inter­molecular π–π stacking completes the three-dimensional network. The anion in the molecular salt, tri­amino­guanidinium 5-({[(1H-tetra­zol-5-yl)meth­yl](nitro)­amino}­meth­yl)tetra­zol-1-ide, (II), CH 9 N 6 + ·C 4 H 5 N 10 O 2 - , displays intra­molecular π–π stacking and in the crystal, N—H∙∙∙N and N—H∙∙∙O hydrogen bonds link the components of the structure, forming a three-dimensional network. In the crystal of di­ammonium bis­[(tetra­zol-1-id-5-yl)meth­yl]nitramide monohydrate, (III), 2NH 4 + ·C 4 H 4 N 10 O 2 2- ·H 2 O, O—H∙∙∙N, N—H∙∙∙N, and N—H∙∙∙O hydrogen bonds link the components of the structure into a three-dimensional network. In addition, there is inter­molecular π–π stacking. In all three structures, the central N atom of the nitramide is mainly sp 2 -hybridized. Bond lengths indicate delocalization of charges on the tetra­zole rings for all three compounds. Compound (II) was found to be a non-merohedral twin and was solved and refined in the major component.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Synthesis and characterization of multicyclic oxadiazoles and 1-hydroxytetrazoles as energetic materials

Synthesis and characterization of several multicyclic oxadiazoles, 3,5-bis(4-nitrofurazan-3-yl)-1,2,4-oxadiazole, 3,3'-bis(4-nitrofurazan-3-yl)-5,5'-bi(1,2,4-oxadiazole), 3-(4-nitrofurazan-3-yl)-1,2,4-oxadiazol-5-amine, and salts of 1-hydroxytetrazoles, ammonium 5,5'-(1,2,4-oxadiazole-3,5-diyl)bis(1H-tetrazol-1-olate) and hydroxylammonium 5,5'-{[3,3'-bi(1,2,4-oxadiazole)]-5,5'-diyl}bis(1H-tetrazol-1-olate), as energetic materials are reported here. Two of the compounds, 3,5-bis(4-nitrofurazan-3-yl)-1,2,4-oxadiazole and 3,3'-bis(4-nitrofurazan-3-yl)-5,5'-bi(1,2,4-oxadiazole), have attractive single crystal densities of 1.91 and 1.94 g·cm –3 (at 20°C), respectively. The design of these materials has been based on the idea that these multicyclic compounds with a 1,2,4-oxadiazole core will have good thermal stability and high density because of their 3,5-substitution pattern and the possibility of achieving a planar conformation. The various synthetic approaches and interesting chemistry observed during the construction of these new heterocycles has been described.

1,2,4-oxadiazoles↗

Azido and tetrazolo 1,2,4,5-tetrazine N-oxides

This paper presents the synthesis and characterization of the oxidation products of 3,6-diazido-1,2,4,5-tetrazine (1) and 6-amino-[1,5-b]tetrazolo-1,2,4,5-tetrazine (2). 3,6-Diazido-1,2,4,5-tetrazine-1,4-dioxide was produced from oxidation with peroxytrifluoroacetic acid, and more effectively using hypofluorous acid, and 2 can be oxidized to two different products, 6-amino-[1,5-b]tetrazolo-1,2,4,5-tetrazine mono-N-oxide and di-N-oxide. These N-oxide compounds display promising performance properties as energetic materials.

1,2,4,5-tetrazine↗

Tetrazolyl Triazolotriazine: A New Insensitive High Explosive

A triazolotriazine carbonitrile ( 1 ) was formed by diazotization of 3–amino–5–cyano–1,2,4–triazole followed by treatment with nitroacetonitrile. Cyclization of the C≡N bond with sodium azide results in a tetrazolyl triazolotriazine ( 2 ). Formation of the sodium salt of 2 , followed by metathesis with [PPN][Cl] resulted in the organic salt 3 . Compounds 1 , 2 , and 3 were characterized by elemental analysis and infrared, 1 H, and 13 C{ 1 H} NMR spectroscopy and 1 and 3 were characterized by single–crystal X–ray diffraction. Compound 2 has a density of 1.819 g cm –1 , is thermally stable up to 305 °C, and is insensitive to impact, friction, and electrical discharge. The detonation pressure and velocity of 2 are calculated to be 27.04 GPa and 8.312 km s –1 , respectively, making this a 1,3,5–triamino–2,4,6–trinitrobenzene (TATB) replacement candidate.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

An Energetic Triazolo-1,2,4-Triazine and its N-Oxide

The reaction of 3-amino-5-nitro-1,2,4-triazole with nitrous acid produces the corresponding diazonium salt. When the diazonium salt is treated with nitroacetonitrile a subsequent condensation and cyclization reaction occurred to produced 4- amino-3,7-dinitrotriazolo-[5,1-c][1,2,4] triazine (DPX-26). X-ray crystallographic analysis shows that the DPX-26 has a density of 1.86 g/cm 3 while it is calculated to have a heat of formation of 398.3 kJ/mol. DPX-26 is predicted to approach the explosive performance of RDX but displays significantly better safety properties. Oxidation of DPX-26 using hypofluorous acid produces 4-amino-3,7- dinitrotriazolo-[5,1-c][1,2,4] triazine 4-oxide (DPX-27), and is also predicted to be a high performance material with enhanced safety properties.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Synthesis and Thermal Behavior of a Fused, Tricyclic 1,2,3,4‐Tetrazine Ring System

Abstract This study presents the synthesis and characterization of a fused, tricyclic 1,2,3,4‐tetrazine ring system. The molecule is synthesized in a three‐step process from 5,5′‐dinitro‐bis,1,2,4‐triazole via a di‐N‐amino compound. Oxidation to form the azo‐coupled fused tricyclic 1,2,3,4‐tetrazine is achieved using tert ‐butyl hypochlorite as the oxidant. The di‐N‐amino compound and the desired fused tricyclic 1,2,3,4‐triazine display interesting thermal behavior and are predicted to be high‐performance energetic materials.

Chavez, David E.↗

Synthesis and Thermal Behavior of a Fused, Tricyclic 1,2,3,4‐Tetrazine Ring System

Abstract This study presents the synthesis and characterization of a fused, tricyclic 1,2,3,4‐tetrazine ring system. The molecule is synthesized in a three‐step process from 5,5′‐dinitro‐bis,1,2,4‐triazole via a di‐N‐amino compound. Oxidation to form the azo‐coupled fused tricyclic 1,2,3,4‐tetrazine is achieved using tert ‐butyl hypochlorite as the oxidant. The di‐N‐amino compound and the desired fused tricyclic 1,2,3,4‐triazine display interesting thermal behavior and are predicted to be high‐performance energetic materials.

Chavez, David E.↗

Crystal structure of 2-diazoimidazole-4,5-dicarbonitrile

In the title compound, C 5 N 6 , all the atoms are approximately coplanar. In the crystal, molecules are packed with short contact distances of 2.885 (2) (between the diazo N atom connected to the ring and a cyano N atom on a neighboring molecule) and 3.012 (2) Å (between the terminal diazo N atom and an N atom of a neighboring imidazole ring).

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

2-Nitro-1,3-dinitrooxypropane

The title compound, C 3 H 5 N 3 O 8 , was synthesized by reacting 2- nitropropane-1,3-diol with acetyl nitrate. The molecule is bisected by a crystallograpic mirror plane. In the crystal, the molecules pack in a ribbon-like fashion along the c axis, with the central nitro groups pointing in the same direction. C–H∙∙∙O contacts apparently provide some additional packing stabilization.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗