Molecular dynamic simulation of performance of modified BAMO/AMMO copolymers and their effects on mechanical properties of energetic materials.

Based on molecular dynamic method, densities, mechanical behavior and mechanical performance of P(BAMO/ AMMO) (Polymer 1) and two novel modified P(BAMO/AMMO) (Polymer 2: containing amino group, Polymer 3: containing nitro group), and their effects on mechanical properties of four energetic materials are investigated, the main results are as follow: Polymer 2 (1.235 g/cm, 240 ± 5 K) and Polymer 3: 1.281 g/cm, 181 ± 3 K) possess higher densities and lower glass transition temperatures than Polymer 1 (1.

CL-20-Based Cocrystal Energetic Materials: Simulation, Preparation and Performance.

The cocrystallization of high-energy explosives has attracted great interests since it can alleviate to a certain extent the power-safety contradiction. 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaaza-isowurtzitane (CL-20), one of the most powerful explosives, has attracted much attention for researchers worldwide. However, the disadvantage of CL-20 has increased sensitivity to mechanical stimuli and cocrystallization of CL-20 with other compounds may provide a way to decrease its sensitivity.

Theoretical study on stabilization mechanisms of nitrate esters using aromatic amines as stabilizers.

The propellants of nitrate esters can be stabilized by some aromatic amines practically. To probe the mechanism of this phenomenon, we performed DFT calculations on: (1) The decompositions of nitrate esters (with and without the catalysis of NO) and (2) the reaction between the stabilizers and the nitro dioxide (NO is released during the storage of nitrate esters). The structures on the reaction paths (reactants, intermediates and products) were optimized at the (U)B3LYP/6-31G** level.

A naked-eye on-off-on molecular "light switch" based on a reversible "conformational switch" of G-quadruplex DNA.

Herein, we report a new strategy for developing an on-off-on molecular "light switch" by utilizing the pH value to control the "conformational switch" of G-quadruplex DNA. A novel ruthenium(II) complex with an emission enhancement factor of 150 was synthesized and introduced to detect the switch by the naked eye. The "light switch" can be repeatedly cycled off and on through the addition of H(+) and OH(-), respectively.

4-[4-(4-Amino-1,2,5-oxadiazol-3-yl)-1,2,5-oxadiazol-3-yl]-1,2,5-oxadiazol-3-amine.

The complete molecule of the compound, C(6)H(4)N(8)O(3), is generated by a crystallographic twofold rotation axis that runs through the central ring. The flanking ring is twisted by 20.2 (1)° with respect to the central ring.

Syntheses, Structural Characterization and Thermoanalysis of Transition-Metal Compounds Derived from 3,5-Dinitropyridone.

Nine metal compounds of Mn(II), Zn(II) and Cd(II) derived from dinitropyridone ligands (3,5-dinitro-pyrid-2-one, 2HDNP; 3,5-dinitropyrid-4-one, 4HDNP and 3,5-dinitropyrid-4-one-N- hydroxide, 4HDNPO) were characterized by elemental analysis, FT-IR and partly by TG-DSC. Three of which were further structurally characterized by X-ray single-crystal diffraction analysis. The structures of the three compounds, Mn(4DNP)(2)(H(2)O)(4), 4, Zn(4DNPO)(2)(H(2)O)(4), 8, and Cd(4DNPO)(2)(H(2)O)(4), 9, crystallize in the monoclinic space group P2(1)/n and Z = 2, with a = 8.

Crystal Structures and Thermal Properties of Two Transition-Metal Compounds {[Ni(DNI)(2)(H(2)O)(3)][Ni(DNI)(2) (H(2)O)(4)]}.6H(2)O and Pb(DNI)(2)(H(2)O)(4) (DNI = 2,4-Dinitroimidazolate).

Two transition-metal compounds derived from 2,4-dinitroimidazole, {[Ni(DNI)(2)(H(2)O)(3)][Ni(DNI)(2) (H(2)O)(4)]}.6H(2)O, 1, and Pb(DNI)(2)(H(2)O)(4), 2, were characterized by elemental analysis, FT-IR, TG-DSC and X-ray single-crystal diffraction analysis. Crystal data for 1: monoclinic, space group C2/c, a = 26.

Thermal behavior of 1,1-diamino-2,2-dinitroethylene.

The thermal behavior of 1,1-diamino-2,2-dinitroethlene (DADNE) was followed by differential scanning calorimetry (DSC) and thermogravimetry (TG). In addition, it was further investigated by the combination techniques of in situ thermolysis cell or fast thermolysis probe with rapid-scan Fourier transform infrared spectroscopy (thermolysis/RSFT-IR and fast thermolysis/RSFT-IR) and by mass spectroscopy (MS). The results showed that there was a phase transition (beta-DADNE to gamma-DADNE) at the temperature of 119 degrees C, and that the gas products of DADNE consisted of CO2, CO, NO2, NO, N2O, HCN, and HNCO, of which CO2, NO, N2O, and HCN present themselves in both the first and second stages of DADNE decomposition process, whereas CO, NO2, and HNCO are only caused by the second stage, in air atmosphere.