Discussed herein is the synthesis of bis­(1,2,4-oxadiazole)­bis­(methylene) dinitrate, determination of its crystal structure by X-ray diffractometry, calculations of its explosive performance, and sensitivity measurements. Steps taken to optimize the synthesis process and to improve yields of the dinitrate are also discussed. Bis­(1,2,4-oxadiazole)­bis­(methylene) dinitrate has a calculated detonation pressure 50% higher than that of TNT. The dinitrate compound exhibits a relatively high decomposition temperature that is rarely observed for nitrate-based compounds. The dinitrate was found to have lower sensitivities to impact and friction compared with RDX. It is believed that intramolecular hydrogen bonding observed in the crystal lattice assists in the relatively high thermal stability and relatively low sensitivity of the material.

The efficient and scalable synthesis of 3,3'-bis-isoxazole-5,5'bis-methylene dinitrate and its energetic properties are described. The material has favorable sensitivity properties;e nergetic properties point toward its potentiala sb oth am elt-castable secondary explosive and as ap ropellant plasticizer.The development of high-energy-density materials (HEDMs) [1] with good performance and low sensitivity is ac ommon goal amongstt hose with an interest in the field of energetic materials. HEDMs are divided into two main groups:e xplosives and propellants. Explosive materials contain as ignificant amount of potentiale nergy that produces as ignificant amount of light, heat, sound,a nd pressure when this energy is released suddenly.W hen this phenomenon occurs,i ti sk nown as an explosion. Ap ropellant is an energetic substance that is used to project av ehicle, bullet, or other object, typically through the formationo fhot, low-molecular-weight gases.Twor espective subareaso fe xplosives and propellants are melt-castable materials and energetic plasticizers.A ccording to the review by Ravi and co-workers, [2] an ideal melt-cast material is defined as having al ow vapor pressure (inhalation toxicity), am elting point between 70 and 120 8C, as ignificant difference between the melting temperature and the temperature of decomposition, ah igh density,l ow sensitivity,a nd a" greener" synthesis. Traditional melt-cast materials are based on trinitrotoluene (TNT), but environmental concerns have led to its replacement with dinitroanisole (DNAN)-based melt-castable eutecticf ormulations. [3] However,D NAN, with ad ensity of 1.52 gcm À3 ,a nd ad etonation velocity of 5670 ms À1 ,i saless powerful explosive than TNT. [4] Thus, there is an interest in de-

The efficient and scalable synthesis of 3,3′‐biisoxazole‐4,4′,5,5′‐tetrakis(methyl nitrate) and its energetic properties are described. The synthesis features a metal‐free [3+2] cycloaddition of an electron‐rich internal alkyne and a nitrile oxide by simple heating, without using halogenated solvents. The material has favorable sensitivity properties, and its energetic properties point toward its potential as a nitrate plasticizer and highly explosive material.

Reaction of the neutral P(H)NP ligand [HN(SiMe(2)CH(2)PPh(2))(2)] with tungsten hexacarbonyl resulted in coordination of P(H)NP through both phosphorus donor atoms to form the tungsten complex [W(P(HN)P)(CO)(4)] (1). Reaction of P(H)NP with tris(acetonitrile)tricarbonyl tungsten gave both facial and meridional tridentate isomers [W(P(H)NP)(CO)(3)] (2-fac and 3-mer). These three d(6) tungsten complexes could be interconverted under appropriate conditions. The thermodynamically favored isomer 3 was protonated to form seven-coordinate [W(P(H)NP)(CO)(3)H][BF(4)] (4). A related series of cationic tungsten(II) halide complexes was synthesized, [W(P(H)NP)(CO)(3)X](+) (6, X = I; 7, X = Br; 8, X = Cl; 9, X = F), by various routes. All of the tungsten(II) complexes underwent deprotonation at the amine site of the P(H)NP ligand when triethylamine was added, resulting in neutral seven-coordinate complexes. Variable temperature (1)H, (31)P{(1)H}, and (13)C{(1)H} NMR spectroscopy showed fluxional behavior for all the seven-coordinate complexes reported here. Analysis of IR and NMR spectroscopic data showed trends through the series of coordinated halides. Crystal structures of tetracarbonyl 1, meridional tricarbonyl 3, and cationic hydride 4 were determined to confirm the coordination mode of the P(H)NP ligand.

The crystal structure and packing of the energetic compound 3,3′-bis-isoxazole-5,5′-bis-methyl­ene dinitrate is reported. Major FTIR, Raman, UV absorption peaks, as well as experimental and calculated density are reported.

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A new procedure for the synthesis and isolation of dichloroglyoxime is discussed. This material has historically been synthesized from glyoxime and elemental chlorine gas. Chlorine gas is difficult to handle and control in the laboratory and has a high toxicity profile. Our method for making dichloroglyoxime in high purity uses glyoxime and N-chlorosuccinimide in DMF, with a lithium chloride-based workup. Overall yields are comparable with those obtained using the procedure involving the use of chlorine gas.

A new procedure for the synthesis and isolation of methyl nitroacetate is described. The previously published method required drying the explosive dipotassium salt of nitroacetic acid in a vacuum desiccator, followed by grinding this material into a fine powder with a mortar and pestle prior to esterification. To obtain the desired product, benzene was employed as the extraction solvent, sodium sulfate was used as the drying agent, and two distillations were required. The new procedure eliminates drying and grinding of the explosive dipotassium salt, employs ethyl acetate or dichloromethane as the extraction solvent, eliminates the need for a drying agent, and requires a single distillation to furnish the end product in high yield and purity.