The electrical resistivity of amorphous alloys at low temperatures

Willer, J.; Fritsch, Gerhard; Rausch, W.; Lüscher, E.

doi:10.1007/bf01307224

Cited by 16 publications

(6 citation statements)

References 17 publications

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“…Recently, another type of polycyclic nitramine, spirobicyclic nitramines such as TNSD (tetranitrotetraazaspirodecane) and TNSU (tetranitrotetraazaspiroundecane), − which are formed by two nitroaza rings sharing a common carbon atom, were investigated as promising candidates of HEDMs. To date, there have been a series of experimental studies on TNSD and TNSU.…”

Section: Introductionmentioning

confidence: 99%

Theoretical Studies on the Structures, Thermodynamic Properties, Detonation Properties, and Pyrolysis Mechanisms of Spiro Nitramines

et al. 2006

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Density function theory (DFT) has been employed to study the geometric and electronic structures of a series of spiro nitramines at the B3LYP/6-31G level. The calculated results agree reasonably with available experimental data. Thermodynamic properties derived from the infrared spectra on the basis of statistical thermodynamic principles are linearly correlated with the number of nitramine groups as well as the temperature. Detonation performances were evaluated by the Kamlet-Jacobs equations based on the calculated densities and heats of formation. It is found that some compounds with the predicted densities of ca. 1.9 g/cm3, detonation velocities over 9 km/s, and detonation pressures of about 39 GPa (some even over 40 GPa) may be novel potential candidates of high energy density materials (HEDMs). Thermal stability and the pyrolysis mechanism of the title compounds were investigated by calculating the bond dissociation energies (BDE) at the B3LYP/6-31G level and the activation energies (E(a)) with the selected PM3 semiempirical molecular orbital (MO) based on the unrestricted Hartree-Fock model. The relationships between BDE, E(a), and the electronic structures of the spiro nitramines were discussed in detail. Thermal stabilities and decomposition mechanisms of the title compounds derived from the B3LYP/6-31G BDE and the UHF-PM3 E(a) are basically consistent. Considering the thermal stability, TNSHe (tetranitrotetraazaspirohexane), TNSH (tetranitrotetraazaspiroheptane), and TNSO (tetranitrotetraazaspirooctane) are recommended as the preferred candidates of HEDMs. These results may provide basic information for the molecular design of HEDMs.

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Section: Introductionmentioning

confidence: 99%

Theoretical Studies on the Structures, Thermodynamic Properties, Detonation Properties, and Pyrolysis Mechanisms of Spiro Nitramines

et al. 2006

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“…This compound was prepared by the procedure of Willer, Campbell, and Storey. 12 The decomposition point was 187 °C (lit. 12 187 °C).…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

“…12 The decomposition point was 187 °C (lit. 12 187 °C). The crystals for the X-ray structure determination were grown by slow evaporation of an acetone solution.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

“…nitrourethanes by the tandem nitration−oxidative desulfurization of cyclic thiourethanes using acetyl nitrate. 12 One of the compounds synthesized in high yield using this technique was the interesting spiro-cyclic compound, 1,6-dinitro-3,8-dioxa-1,6diazaspiro [4.4]nonane-2,7-dione (1; see Figure 1). The Energy software program predicts that 1 has a density of 1.88 g/cm 3 and TNT-like detonation properties.…”

Section: ■ Introductionmentioning

confidence: 99%

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Synthesis, Prediction, and Determination of Crystal Structures of (R/S)- and (S)-1,6-Dinitro-3,8-dioxa-1,6-diazaspiro[4.4]nonane-2,7-dione

Willer

Storey

Deschamps

et al. 2012

Crystal Growth & Design

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Spiro-cyclic compounds frequently have screw-type symmetry (C 2) and are therefore optically active even though they do not contain an asymmetric carbon atom. (R/S)-1,6-Dinitro-3,8-dioxa-1,6-diazaspiro[4.4]nonane-2,7-dione is such a molecule. A blind crystal structure prediction study of structures containing one molecule in the asymmetric unit and considering all 230 space groups was undertaken using a dispersion-corrected density functional approach, which found a packing that matched the experimental structure of the (R/S) form as the lowest energy packing alternative. The densities of (R/S)- and (S)- or (R)-1,6-dinitro-3,8-dioxa-1,6-diazaspiro[4.4]nonane-2,7-dione calculated for the optimized experimental crystal structures confirmed that there is a small difference in the densities of the racemate and the optically active compound, with the optically active material being slightly more dense (1.875 versus 1.842 g/cm3). (R/S)-1,6-Dinitro-3,8-dioxa-1,6-diazaspiro[4.4]nonane-2,7-dione was synthesized as previously described. Synthesis of the pure (S)-stereoisomer was accomplished by resolution of the racemic dithiourethane using a previously described method, followed by reaction of the pure enantiomer with acetyl nitrate. The absolute configuration of the l-3,8-dioxa-1,6-diazaspiro[4.4]nonane-2,7-dithione was established as (S)- by redetermining the crystal structure at 150 K. The racemate crystallizes in space group P21/n with a density of 1.835 g/cm3 (296 K). The (S)-compound crystallizes in space group P212121 with a density of 1.854 g/cm3 (296 K). This is the first demonstration of a difference in the density between the racemic mixture and the optically pure stereoisomer of an energetic material. It is also an apparent violation of Wallach’s rule, which states that racemic crystals tend to be denser than their optically active counterparts.

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“…We developed an innovative modified procedure based on the Schmidt procedure that increased the yield to above 90% and allowed multi-pound quantities of ANF to be synthesized in a day in a 50-liter reactor. The main changes were to raise the reaction temperature, increase the hydrogen peroxide concentration from 30% to 50-70% and not isolating the ANF after each addition [82 ]. The ready availably of ANF suggests that molecules such as HANNF and ANNF should be re-examined as energetic materials.…”

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confidence: 99%

Calculation of the Density and Detonation Properties of C, H, N, O and F Compounds: Use in the Design and Synthesis of New Energetic Materials

Willer

2019

J. Mex. Chem. Soc.

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The estimation of the density and detonation properties of C, H, N, O, F explosives is discussed. A simple computer program, “Energy”, first developed at the Naval Weapons Center-China Lake in the early 1980’s is presented in an updated form. This program allows the rapid calculation of the estimated properties of both known and hypothetical energetic materials. A review of the use of this program in the synthesis of new energetic materials is given.

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The electrical resistivity of amorphous alloys at low temperatures

Cited by 16 publications

References 17 publications

Theoretical Studies on the Structures, Thermodynamic Properties, Detonation Properties, and Pyrolysis Mechanisms of Spiro Nitramines

Theoretical Studies on the Structures, Thermodynamic Properties, Detonation Properties, and Pyrolysis Mechanisms of Spiro Nitramines

Synthesis, Prediction, and Determination of Crystal Structures of (R/S)- and (S)-1,6-Dinitro-3,8-dioxa-1,6-diazaspiro[4.4]nonane-2,7-dione

Calculation of the Density and Detonation Properties of C, H, N, O and F Compounds: Use in the Design and Synthesis of New Energetic Materials

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