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1

Mixtures of Phase-stabilized Ammonium Nitrate and Tetrazoles as New Gas-generating Agent Compositions

Hasue K., Yoshitake K., Matsukawa M.

Central European Journal of Energetic Materials

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2016

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Vol. 13, no. 1

247--260

EN

New gas-generating agents for air bags have been investigated. Ammonium nitrate does not give off harmful gases nor leave solid residues but goes through contraction and expansion during a series of phase transitions that cause structural damage within the material. In this study, potassium-nitrate-phase-stabilized ammonium nitrate (PSAN) was prepared by a nonhazardous aqueous method. Ammonium nitrate-based propellants have low burning rates. Tetrazoles were selected as they have a large heat of formation and can be used as fuel components for ammonium nitrate-based gas-generating agents. A number of different experiments were conducted on the novel tetrazole/PSAN mixtures in order to evaluate their application as gas-generating agents.

2

Preparation and Characterization of 1-(5-Azido-1H-1,2,4-triazol-3-yl)tetrazole

Izsák D., Klapötke T. M.

Central European Journal of Energetic Materials

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2015

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Vol. 12, no. 3

403--416

EN

This study presents the preparation of 1-(5-azido-1H-1,2,4-triazol-3yl)tetrazole (5) from commercially available chemicals in a five step synthesis. The energetic title compound was comprehensively characterized by various means, including vibrational (IR, Raman) and multinuclear (1H, 13C, 14N, 15N) NMR spectroscopy, mass spectrometry and differential scanning calorimetry. The sensitivities towards various outer stimuli (impact, friction) were determined according to BAM standards. The enthalpy of formation was calculated at the CBS-4M level of theory.

3

Correlations of Charges of Substituent Active Region in C-substituted Tetrazoles with Their Gas-phase Acidity, Hammett Constants, and Charge Distribution in Tetrazolic Rings

Sadlej-Sosnowska N., Murłowska K.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 4

935-945

EN

Electron distribution was investigated in molecules of 5C-substituted tetrazoles by means of Natural Population Analysis. The analysis of the impact of substituents on the excess of p electrons in the ring and on the uniformity of their distribution produced similar results as were recently reported for derivatives of p-benzoic acid. The significant correlation coefficients of the two properties with the Hammett constants have been found. The more uniform the p electron distribution, measured by means of standard deviation of p electrons amounts localized on individual atoms in the ring, the more acidic is the molecule. On the other hand, an increase of the p electron number in the ring brings about an opposite effect. No correlation was found between the substituent charges and the Hammett constants. However, a new variable, namely charge of the substituent active region, composed of charge of a substituent added to charge of the ring Cipso atom, was highly correlated with the Hammett constants, as well as with charge of acidic hydrogen of the >N-H group. The results prove that the set of charges of the substituent active region may be perceived as a theoretical equivalent of the experimental set of Hammett constants and that it is closely related to properties of this group of compounds.

4

Hydrazinium 5-Aminotetrazolate: an Insensitive Energetic Material Containing 83.72% Nitrogen

Fischer N., Klapötke T. M., Scheutzow S., Stierstorfer J.

Central European Journal of Energetic Materials

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2008

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Vol. 5, nr 3-4

3-18

EN

Hydrazinium 5-aminotetrazolate (2) was synthesized via two facile routes. Both the reaction of 5-amino-1H-tetrazole (1) with hydrazine hydrate in aqueous solution and the reaction of 1 with diluted hydrazine solution in THF yield 2 in excellent purities and yields. 2 was characterized comprehensively by X-ray diffraction, IR, Raman and multinuclear NMR spectroscopy, mass spectrometry, elemental analysis and differential scanning calorimetry. The heat of formation was calculated (CMS-4M) using the atomization method to be 373 kJ mol-1. With this value and the X-ray density several detonation parameter (heats of explosion, detonation pressure, detonation velocity, explosion temperature) were calculated with the EXPLO5 computer software. An incredible high value (9516 m s-1) was obtained for the detonation velocity. Therefore experimentally tests to determine the velocity of detonation were performed. In addition the use of 2 in solid propellant compositions was calculated and tested in combination with oxidizers, e.g. ammonium dinitramide. Lastly the sensitivities towards impact, friction and electrostatic discharge were determined with the BAM drophammer, friction tester and an ESD machine.

5

Regioselective Synthesis of New Chelating Bistetrazole Ligands and Study of Their Coper(II) Complexes

Voitekhovich S., Gaponik P. N., Pytleva D. S., Lyakhov A. S., Ivashkevich O. A.

Polish Journal of Chemistry

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2002

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Vol. 76 / nr 10

1371-1380

EN

Synthesis of some new N-substituted bistetrazoles is described. 1,5-Bis(2-tert-butyl- 5-tetrazolyl)-3-oxopentane (btop) is obtained by regioselective alkylation of 1,5-bis(5- tetrazolyl)-3-oxopentane with tert-butyl alcohol in 96% sulphuric acid media. 1,5-Bis(1- methyl-5-tetrazolyl)-3-oxopentane (mtop) is synthesized by exhaustive methylation of 1,5-bis(2-tert-butyl-5-tetrazolyl)-3-oxopentane followed by the removal of tert-butyl group from the formed tetrazolium methyl sulphate in acidic conditions. Isomeric tetrazolium perchlorate is converted in analogous conditions to perchlorate of 1,5-bis(1- methyl-5-tetrazolyl)-3-oxopentane. Synthesized bistetrazoles are found to react with copper(II) chloride in ethyl alcohol or acetone solutions giving solid [Cu(mtop)Cl2] and [Cu(btop)Cl2] complexes. Perchlorate of 1,5-bis(1-methyl-5-tetrazolyl)-3-oxopentane reacts with copper(II) chloride in ethyl alcohol leading to formation of complex [Cu(mtop)Cl2], whereas in aqueous solution complex [Cu(mtop)2](ClO4)2 is formed. According to X-ray study of chloride complexes, Cu(II) is surrounded by a tridentate chelating ligand and two halide anions resulting in distorted square pyramidal geometry.

6

Synthesis and Transformation of 1-Monosubstituted Tetrazoles to Pyrimidinones, Benzoxazoles and Quinazolinediones Through 1,4-Disubstituted Tetrazolium Salts

Voitekhovich S., Gaponik P. N., Lyakhov A. S., Ivashkevich O. A.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 2

253-264

EN

Synthesis and some new transformations of 1-aryltetrazoles into other heterocycles through 1,4-disubstituted tetrazolium salts are described. 1-Aryltetrazoles, quaternized with tert-butanol and diacetone alcohol in perchloric acid media, gave pure 1,3- or 1,4-disubstituted tetrazolium salts or their mixtures. 1,3-Disubstituted tetrazolium salts are slowly converted into the corresponding 1,4-salts under dissolving in perchloric acid. 1,4-Disubstituted tetrazolium salts are recyclized to 2-alkylaminobenzoxazoles, 3-monosubstituted 2,4-quinazolinediones and mixtures of di- and tetrahydropyrimidin-2(1H)- ones in basic conditions.

7

Selective synthesis of 1,3-di- and 1,3,5-trisubstituted tetrazolium salts by tert-butylation of tetrazole, 1- and 5-monosubstituted tetrazoles, isomerization of 1,3-disubstituted salts to 1,4-salts

Gaponik P.N., Voitekhovich S.V., Maruda I.I., Kulak A.A., Ivashkevich O.A.

Polish Journal of Chemistry

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1998

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Vol. 72, nr 10

2247-2253

EN

Tetrazole and its 1- and 5-monosubstituted derivatives are found to react with tert-butyl alcohol in 72% perchloric acid media, yielding selectively 1,3-di- and 1,3,5-trisubstituted tetrazolium salts. 1,3-Disubstituted salts are slowly converted under the same conditions into the corresponding 1,4-disubstituted salts. This transformation may be used for selective synthesis of the latter.