Thermal decomposition of aminotetrazoles
TL;DR: In this article, the authors derived the mechanism of thermal decomposition of aminotetrazoles based on the content of products and the kinetic consideration, and derived two routes of the splitting of tetrazole ring leading either to elimination nitrogen or hydrogen azide.
About: This article is published in Thermochimica Acta.The article was published on 1992-10-01. It has received 122 citations till now. The article focuses on the topics: Thermal decomposition & Tetrazole.
Citations
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TL;DR: The use of nitrogen containing anions and cations contributes to high heats of formations and high densities as discussed by the authors, which makes them very promising candidates for highly energetic materials for industrial or military applications.
Abstract: Energetic salts offer many advantages over conventional energetic molecular compounds. The use of nitrogen containing anions and cations contributes to high heats of formations and high densities. Their low carbon and hydrogen content gives rise to a good oxygen balance. The decomposition of these compounds is predominantly through the generation of dinitrogen which makes them very promising candidates for highly energetic materials for industrial or military applications.
709 citations
TL;DR: In this paper, a new synthesis for 1,5-diamino-1H-tetrazolium nitrate (2a) and perchlorate (2b) was introduced that avoids lead azide as a hazardous byproduct.
Abstract: 1,5-Diamino-1H-tetrazole (2, DAT) can easily be protonated by reaction with strong mineral acids, yielding the poorly investigated 1,5-diaminotetrazolium nitrate (2a) and perchlorate (2b). A new synthesis for 2 is introduced that avoids lead azide as a hazardous byproduct. The reaction of 1,5-diamino-1H-tetrazole with iodomethane (7a) followed by the metathesis of the iodide (7a) with silver nitrate (7b), silver dinitramide (7c), or silver azide (7d) leads to a new family of heterocyclic-based salts. In all cases, stable salts were obtained and fully characterized by vibrational (IR, Raman) spectroscopy, multinuclear NMR spectroscopy, mass spectrometry, elemental analysis, X-ray structure determination, and initial safety testing (impact and friction sensitivity). Most of the salts exhibit good thermal stabilities, and both the perchlorate (2b) and the dinitramide (7c) have melting points well below 100 degrees C, yet high decomposition onsets, defining them as new (7c), highly energetic ionic liquids. Preliminary sensitivity testing of the crystalline compounds indicates rather low impact sensitivities for all compounds, the highest being that of the perchlorate (2b) and the dinitramide (7c) with a value of 7 J. In contrast, the friction sensitivities of the perchlorate (2b, 60 N) and the dinitramide (7c, 24 N) are relatively high. The enthalpies of combustion (Delta(c)H degrees ) of 7b-d were determined experimentally using oxygen bomb calorimetry: Delta(c)H degrees (7b) = -2456 cal g(-)(1), Delta(c)H degrees (7c) = -2135 cal g(-)(1), and Delta(c)H degrees (7d) = -3594 cal g(-)(1). The standard enthalpies of formation (Delta(f)H degrees ) of 7b-d were obtained on the basis of quantum chemical computations using the G2 (G3) method: Delta(f)H degrees (7b) = 41.7 (41.2) kcal mol(-)(1), Delta(f)H degrees (7c) = 92.1 (91.1) kcal mol(-)(1), and Delta(f)H degrees (7d) = 161.6 (161.5) kcal mol(-)(1). The detonation velocities (D) and detonation pressures (P) of 2b and 7b-d were calculated using the empirical equations of Kamlet and Jacobs: D(2b) = 8383 m s(-)(1), P(2b) = 32.2 GPa; D(7b) = 7682 m s(-)(1), P(7b) = 23.4 GPa; D(7c) = 8827 m s(-)(1), P(7c) = 33.6 GPa; and D(7d) = 7405 m s(-)(1), P(7d) = 20.8 GPa. For all compounds, a structure determination by single-crystal X-ray diffraction was performed. 2a and 2b crystallize in the monoclinic space groups C2/c and P2(1)/n, respectively. The salts of 7 crystallize in the orthorhombic space groups Pna2(1) (7a, 7d) and Fdd2 (7b). The hydrogen-bonded ring motifs are discussed in the formalism of graph-set analysis of hydrogen-bond patterns and compared in the case of 2a, 2b, and 7b.
229 citations
TL;DR: In this article, the synthesis, structure, properties and applications of metal derivatives of tetrazoles are generalised and described systematically, and compounds based on the anionic and neutral tetrazole forms, C- and N-mono- and C,N-disubstituted tetrazolas are considered.
Abstract: Published data on the synthesis, structure, properties and applications of metal derivatives of tetrazoles are generalised and described systematically. Compounds based on the anionic and neutral tetrazole forms, C- and N-mono- and C,N-disubstituted tetrazoles are considered.
174 citations
TL;DR: Two metal-organic frameworks, [Zn2(ATA)3 (ATA)2/2] (1) as mentioned in this paper, have been synthesized by the hydrothermal reactions of Zn(II) salts with HATA.
Abstract: Two metal−organic frameworks, [Zn2(ATA)3(ATA)2/2] (1) and [Zn(OH)(ATA)2] (2), have been synthesized by the hydrothermal reactions of Zn(II) salts with HATA. 1 displays a unique four-connected 2D bilayer “hcb” 43.63 topological network, and shows a strong blue fluorescence at room temperature.
165 citations
TL;DR: In this paper, the most widely used types of azole heterocycles are introduced and compared, particularly in terms of their performance characteristics in polyacids containing different functional groups.
149 citations
References
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Book•
30 Sep 1997
TL;DR: In this article, the CHEC III is organized in 15 volumes and closely follows the organization used in the previous edition: Volumes 1 and 2: Cover respectively three and four-membered heterocycles, together with all fused systems containing a three- or four-measured heterocyclic ring.
Abstract: CHEC III is organized in 15 Volumes and closely follows the organization used in the previous edition: Volumes 1 and 2: Cover respectively three- and four-membered heterocycles, together with all fused systems containing a three- or four-membered heterocyclic ring. Volume 3: Five-membered rings with one heteroatom together with their benzo- and other carbocyclic-fused derivatives. Volumes 4, 5 and 6: Cover five-membered rings with two heteroatoms, and three or more heteroatoms, respectively, each with their fused carbocyclic compounds. Volumes 7, 8 and 9: Dedicated to six-membered rings with one, two, and more than two heteroatoms, respectively, again with the corresponding fused carbocylic compounds. Volumes 10, 11 and 12: Cover systems containing at least two directly fused heterocyclic five- and/or six-membered rings: of these Volume 10 deals with bi-heterocyclic rings without a ring junction heteroatom, and Volume 11 deals with 5:5 and 5:6 fused rings systems with at least one ring junction nitrogen, while Volume 12 is devoted to all other systems of five and/or six-membered fused or spiro heterocyclic rings with ring junction heteroatoms. Volumes 13 and 14: Seven-membered and larger heterocyclic rings including all their fused derivatives (except those containing three- or four-membered heterocyclic rings which are included in Volume 1 and 2, respectively). Volume 15: Author, ring and subject indexes.
8,174 citations
TL;DR: In this article, a thermocouple is used to measure the sample temperature in a Stanton HT-D thermobalance, the bead of which is positioned in or near the sample, depending on crucible design.
Abstract: THE use of thermogravimetric data to evaluate kinetic parameters of solid-state reactions involving weight loss (or gain) has been investigated by a number of workers1–4. Freeman and Carroll2 have stated some of the advantages of this method over conventional isothermal studies. To these reasons may be added the advantage of using one single sample for investigation. However, the importance of procedural details, such as crucible geometry, heating rate, pre-history of sample, and particle size, on the parameters has yet to be fully investigated. It is also necessary to ensure accurate temperature measurement, both for precision and also to detect any departure from a linear heating rate due to endo- or exo-thermic reactions. (The effect of these may be largely eliminated by the use of small samples.) In our present work (using a Stanton HT–D thermobalance) the sample temperature is measured directly by means of a thermocouple the bead of which is positioned in or near the sample, depending on crucible design, the wires of which run down a twin-bore rise rod. The connexion between the end of the thermocouple wires on the balance arm and the terminal block is made by 0.001 in. platinum and platinum/rhodium wires5. It has been shown that these wires do not affect the performance of the balance but act merely as a subsidiary damping. From the terminal block compensated cable leads to the cold junction and a potentiometric arrangement for direct measurement of the thermocouple output.
5,770 citations
TL;DR: In this paper, a new method of obtaining the kinetic parameters from thermogravimetric curves has been proposed, which is simple and applicable to reactions which can not be analyzed by other methods.
Abstract: A new method of obtaining the kinetic parameters from thermogravimetric curves has been proposed. The method is simple and applicable to reactions which can not be analyzed by other methods. The effect of the heating rate on thermogravimetric curves has been elucidated, and the master curve of the experimental curves at different heating rates has been derived. The applications of the method to the pyrolyses of calcium oxalate and nylon 6 have been shown ; the results are in good agreement with the reported values. The applicability of the method to other types of thermal analyses has been discussed, and the method of the conversion of the data to other conditions of temperature change has been suggested. From these discussions, the definition of the thermal stability of materials has been criticized.
5,622 citations
4,724 citations
TL;DR: In this article, a direct method for evaluating the gradient of the second-order Moller-Plesset (MP2) energy without storing any quartic quantities, such as two-electron repulsion integrals (ERIs), double substitution amplitudes or the two-particle density matrix, was presented.
1,567 citations