Facile Synthesis and Crystal Structure of 1,1,1,3‐Tetranitro‐3‐azabutane

The synthesis of 1,1,1,3‐tetranitro‐3‐azabutane is disclosed and compared with the known method. The structure of 1,1,1,3‐tetranitro‐3‐azabutane is identified by multi‐nuclear NMR spectroscopy and X‐ray single crystal structure determination.     

New Azidotetrazoles: Structurally Interesting and Extremely Sensitive

The treatment of triaminoguanidinium chloride with two equivalents of sodium nitrite under acidic conditions, followed by the cyclization with stoichiometric amounts of either sodium hydroxide solution or solid sodium carbonate yielded 1‐amino‐5‐azidotetrazole ( 1 ), 5‐azido‐1‐diazidocarbamoyltetrazole ( 2 ), and 1‐(aminoazidocarbamoyl)‐5‐azidotetrazole ( 3 ). The three novel compounds could be isolated by short‐column liquid chromatography by using chloroform in reasonable yields. The mechanism of the formation as well as the decomposition pathway of the materials was investigated and a full characterization of all three compounds is presented. Compounds 1 , 2 , 3 have been characterized by means of Raman and IR as well as multinuclear NMR spectroscopy, mass spectrometry, and X‐ray diffraction studies. Thermal stabilities have been evaluated by differential scanning calorimetry. Theoretical calculations have been performed to ensure the assignment of the vibrational modes obtained from Raman and IR measurements. The sensitivity values obtained from our measurements reflect the behavior of the compounds, which show an extremely high sensitivity toward mechanical as well as thermal stimuli.     

The Energetic Nitrocarbamate O2NN(H)CO[OCH2C(NO2)3] Derived from Phosgene

A new simple synthesis route for 2,2,2‐trinitroethyl chloroformate ( 1 ), from easily available starting materials 2,2,2‐trinitroethanol and phosgene is presented. 2,2,2‐Trinitroethyl carbamate ( 2 ) was obtained by the reaction of 1 with aqueous ammonia. The nitration of 2 with anhydrous nitric acid and sulfuric acid yields 2,2,2‐trinitroethyl nitrocarbamate ( 3 ), which has potential as a perchlorate free high energetic dense oxidizer with a high oxygen balance of Ω(CO₂) = +14.9 %. The thermal stability was studied using differential scanning calorimetry and the energies of formation were calculated on the CBS‐4M level of theory, as well as several detonation parameters and propulsion properties were determined. In addition to full spectroscopic characterization, X‐ray diffraction studies were performed for 2 and 3 .     

Halogenotrinitromethanes: A Combined Study in the Crystalline and Gaseous Phase and Using Quantum Chemical Methods

The halogenotrinitromethanes FC(NO₂)₃ ( 1 ), BrC(NO₂)₃ ( 2 ), and IC(NO₂)₃ ( 3 ) were synthesized and fully characterized. The molecular structures of 1 – 3 were determined in the crystalline state by X‐ray diffraction, and gas‐phase structures of 1 and 2 were determined by electron diffraction. The Hal?C bond lengths in F?, Cl?, and Br?C(NO₂)₃ in the crystalline state are similar to those in the gas phase. The obtained experimental data are interpreted in terms of Natural Bond Orbitals (NBO), Atoms in Molecules (AIM), and Interacting Quantum Atoms (IQA) theories. All halogenotrinitromethanes show various intra‐ and intermolecular non‐bonded interactions. Intramolecular N ??? O and Hal ??? O (Hal=F ( 1 ), Br ( 2 ), I ( 3 )) interactions, both competitors in terms of the orientation of the nitro groups by rotation about the C?N bonds, lead to a propeller‐type twisting of these groups favoring the mentioned interactions. The origin of the unusually short Hal?C bonds is discussed in detail. The results of this study are compared to the molecular structure of ClC(NO₂)₃ and the respective interactions therein.     

Bis(2,4,6‐trimethylphenyl)tellurium(IV) Dicyanide: the First Crystal Structure for a Tellurium Cyanide of the Type R2Te(CN)2

The reaction of Mes₂TeF₂ (Mes = 2,4,6‐trimethylphenyl) with trimethylsilyl cyanide yields the corresponding tellurium(IV) dicyanide Mes₂Te(CN)₂. Isolation of suitable crystals allows the determination of the first crystal structure of a compound of the type R₂Te(CN)₂.     

Molecular structure of hydrazoic acid with hydrogen-bonded tetramers in nearly planar layers

Hydrazoic acid (HN(3))--potentially explosive, highly toxic, and very hygroscopic--is the simplest covalent azide and contains 97.7 wt % nitrogen. Although its molecular structure was established decades ago, its crystal structure has now been solved by X-ray diffraction for the first time. Molecules of HN(3) are connected to each other by hydrogen bonds in nearly planar layers parallel to (001) with stacking sequence A, B, ... The layer distance, at 2.950(1) ?, is shorter than that in 2H-graphite [3.355(2) ?]. The hydrogen bonds N-H···N are of great interest, since the azido group consists of three homonuclear atoms with identical electronegativity, but different formal charges. These hydrogen bonds are bifurcated into moderate ones with ≈2.0 ? and into weak ones with ≈2.6 ?. The moderate ones build up tetramers (HN(3))(4) in a nearly planar net of eight-membered rings. To the best of our knowledge, such a network of tetramers of a simple molecule is unique.     

Isolation of a stable covalent selenium azide RSeN3

The first covalent selenium azide 2-Me2NCH2C6H4SeN3 has been synthesized and fully characterized including crystal structure determination. As shown by the experimental results, the relative stability of RSeN3 highly depends on the nature of the coordinating ability of the substituent R, resulting in a heterocyclic zwitterionic structure.     

Design and characterization of new advanced energetic biopolymers based on surface functionalized cellulosic materials

A new class of energetic biopolymers, which contain nitrate ester (O-NO₂) and nitramine (N-NO₂) as explosophoric groups, was successfully synthesized by surface modification of renewable pristine cellulose (PC) and microcrystalline cellulose (MCC) via epichlorohydrin-mediated amination followed by nitration process to produce new promising energetic aminated and nitrated cellulose and microcrystalline cellulose (APCN and AMCCN). Their structural, thermal, crystallinity and morphological features were examined and compared to those of the common cellulose nitrate. Furthermore, their energetic performances were evaluated by EXPLO5 V6.04 software. Experimental results confirm the successful chemical functionalization process to develop insensitive APCN and AMCCN with outstanding features such as nitrogen content of 15.01% and 15.39%, density of 1.692 g/cm³ and 1.708 g/cm³, and detonation velocity of 7526 m/s and 7752 m/s, respectively, which are significantly higher than those of the nitrated unmodified cellulosic biopolymers. The present investigation provides a suitable pathway to design new insensitive and energy-rich dense cellulosic biopolymers for potential application in high-performance solid propellants and composite explosives.