用分子子图法计算硝基呋咱化合物的生成热

用新的分子子图法计算硝基呋咱类化合物的生成热,将呋咱基团视为母体,即基子图项;硝基、叠氮基、甲基、氰基拆分为一个个原子,从原子的角度来分分子子图,将碳、氢、氧、氮原子视为取代基,即亚子图项.同时考虑呋咱基团的个数,考虑1位、 2位、 3位、 4位上碳、氢、氧、氮原子及双键、叁键对生成热的影响,还考虑不饱和度、总硝基个数、环的个数(除呋咱环)、氮氮及氮氧双键的个数对生成热的影响.用这种新的分子子图编码方法,对硝基呋咱化合物的生成热进行了拟合和预估,取得了满意的结果,其回归方程的相关系数达到了0.9954.     

Synthesis,Characterization and Properties of Ureido‐Furazan Derivatives

The reaction of a variety of amino‐furazans with chlorosulfonyl isocyanate was carried out to synthesize ureido‐furazans. The nitration to nitro‐ureido‐furazan was successful in the case of 3‐nitro‐4‐nitroureido‐furazan and 3,4‐dinitroureido‐furazan. Furthermore, furazan derivatives linked to a second amino‐oxadiazole were synthesized. All compounds were intensively characterized by X‐ray diffraction measurements, NMR spectroscopy, vibrational spectroscopy (IR, Raman), BAM sensitivity tests and differential thermal analysis. The energetic properties were calculated using Explo5 6.03 .     

Displacement polymerization—V. Synthesis and characterization of polyarylethers containing furoxan and furazan units

Two new polyarylethers containing furoxan and furazan units respectively have been synthesized by nucleophilic displacement polymerization using the corresponding activated dihalo compound and disodium bisphenolate in anhydrous aprotic solvent. The polyether obtained from bis(p-chlorophenyl)furoxan has higher molecular weight than that derived from bis(p-chlorophenyl)furazan. The structures of the polymers were confirmed by i.r. spectra and elemental analyses. The furoxan polymer shows better thermal stability than the furazan polymer. The former is partly crystalline whereas the latter is amorphous. Both polymers are soluble in halogenated hydrocarbons and polar solvents.     

Energetic materials based on poly furazan and furoxan structures

Furazan and furoxan represent fascinating explosophoric units with intriguing structures and unique properties. Compared with other nitrogen-rich heterocycles, most poly furazan and furoxan-based heterocycles demonstrate superior energetic performances due to the higher enthalpy of formation and density levels. A large variety of advanced energetic materials have been achieved based on the combination of furazan and furoxan moieties with different kinds of linkers and this review provides an overview of the development of energetic poly furazan and furoxan structures during the past decades, with their physical properties and detonation characteristics summarized and compared with traditional energetic materials. Various synthetic strategies towards these compact energetic structures are highlighted by covering the most important cyclization methods for construction of the hetercyclic scaffolds and the following modifications such as nitrations and oxidations. Given the synthetic availabilities and outstanding properties, energetic materials based on poly furazan and furoxan structures are undoubtedly listed as a promising candidate for the development of new-generation explosives, propellants and pyrotechnics.     

Synthesis, Characterization and Thermal Properties of Energetic Compounds Derived from 3-Amino-4-(tetrazol-5-yl)furazan

Five energetic compounds, 3,3‐bis(tetrazol‐5‐yl)‐4,4‐azofurazan (DTZAF), 3‐nitro‐4‐(tetrazol‐5‐yl)furazan (NTZF), hydrazinium 3‐amino‐4‐(tetrazol‐5‐yl)furazan (HATZF), triaminoguanidinium 3‐amino‐4‐(tetrazol‐ 5‐yl)furazan (TAGATZF) and guanylureaium 3‐amino‐4‐(tetrazol‐5‐yl)furazan (MATZF), were prepared using 3‐amino‐4‐(tetrazol‐5‐yl)furazan (ATZF) as starting material and their structures were characterized by FT‐IR, ¹H NMR, ¹³C NMR and elemental analysis. The properties of NTZF were estimated:density is 1.67 g/cm³, enthalpy of formation +415.41 kJ/mol and detonation velocity 8257.83 m/s. The main thermal properties of four compounds, DTZAF, HATZF, TAGATZF and MATZF, were analyzed by TG and DSC techniques and the results showed that their melting points are 251.9, 159.7, 205.4 and 211.4°C, respectively, and their first decomposition temperatures are 256.7, 258.6, 231.7 and 268.6°C, respectively. The fact that their decomposition temperatures were over 230°C showed that they exhibit better thermal stability.     

Theoretical studies on heats of formation,detonation properties,and bond dissociation energies of monofurazan derivatives

The heats of formation (HOFs) for a series of monofurazan derivatives were calculated by using density functional theory. It is found that the ? CN or ? N₃ group plays a very important role in increasing the HOF values of the furazan derivatives. The detonation velocities and detonation pressures of the furazan derivatives are evaluated at two different levels. The results show that the ? NF₂ group is very helpful for enhancing the detonation performance for the furazan derivatives, but the case is quite the contrary for the ? CH₃ group. An analysis of the bond dissociation energies and bond orders for the weakest bonds indicate that the substitutions of ? CN group are favorable and enhances the thermal stability of the furazan derivatives, but the ? NO₂ groups produce opposite effects. These results provide basic information for the molecular design of novel high‐energy density materials. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010     

Extraction of copper(II) and nickel(II) by cyclic trioximes and cyclic furazan oximes

The extraction properties of 1,2,3-cyclopentanetrione trioxime (H₃CPT) and its furazan, and of 4-t-butyl-1,2,6-cyclohexanetrione trioxime (H₃BHT) and its furazan are described. H₃CPT was found to be too soluble in water and was therefore of no use in extraction but H₃BHT was satisfactory. The extracted copper and nickel chelates of H₃BHT precipitate by agglomeration caused by intermolecular hydrogen bonding and/or coordination of the third oxime group. This precipitation blocked back extraction. The furazan oximes derived from these trioximes did not form copper or nickel chelates under extraction conditions.     

Mass spectra of substituted and annelated benzofurazan-1-oxides

Electron impact positive ion spectra of ten substituted or annelated benzofurazan-1-oxides are reported. While most of the molecular ions lose either NO˙ + NO˙, or NO˙ + CO, some also lose CO as an initial fragment. One of the fragmentation pathways for 4-methylbenzofurazan-1-oxides involves initial ˙CHO loss. With the annelated benzofurazan-1-oxides (naphtho[1,2-c]furazan oxide and quinolo[3,4-c]furazan oxide), loss of N₂O₂ is followed by a retro-Diels–Alder elimination of butadiyne or propynenitrile, respectively from the aryne radical cation. In the case of quinolo[5,6-c]furazan oxide, loss of N₂O₂ from the molecular ion must be followed by substantial rearrangement to enable the observed loss of propynenitrile to take place.     

Extraction of copper(II) and nickel(II) by nopinoquinone dioxime

In the research for a selective extractant for nickel a strained dioxime, β-nopinoquinone dioxime, has been studied in its extraction properties for copper(II) and nickel(II). Spectroscopic investigations (ESR and NMR) showed that both copper and nickel are extracted as a N,N-coordinated chelate. The extraction studies showed that the use of strained instead of aliphatic dioximes makes the extraction more convenient because of the higher extraction rate, but the selectivity for nickel above copper disappears.δ-nopinoquinone dioxime is easily converted into its furazan by treatment with 1N NaOH. This furazan is a rather weak ligand without significant extraction capacities.     

Orientation in the nitration of 3-phenyl-4-substituted furazans

The nitration of 3-phenyl-4-substituted furazans with various nitrating agents was investigated. It is shown that the orientation of the nitro group that is incorporated in the phenyl ring is determined by the substituent in the 4 position of the furazan ring, whereas the introduction of a furazan substituent in the phenyl ring lowers the reactivity of the latter. The corresponding dinitro derivatives can be obtained by means of acid mixtures.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 27–29, January, 1982.     

Studies on quinones

Phenanthro[1, 2-c][1, 2, 5]oxadiazole-10, 11-dione (phenanthrene quinone furazan, I), like anthraquinone furazan, is capable of adding nucleophilic agents to carbon atom 4 of the carbon skeleton or to the oxygen of the carbonyl group. Thus, its reactions with thiophenol and benzenesulfinic acid, with subsequent oxidation lead, respectively, to the substituted quinones II and IV, the latter of which is converted by the action of benzenesulfinic acid into the benzenesulfonic ester V.For part IX, see [1]     

Synthesis of 3-amino-4-(thienyl-2)furazan

3-Amino-4-(thienyl-2)furazan (3) has been synthesized from 2-acetylthiophene (4) by several routes. Nitrosation of 4, followed by oximation of the resulting oxime salt 5, gave a 6:1 mixture of the E,E and E,Z isomers of thienylglyoxime (1). Estimation of differences and analogies of these isomers' reactivity have been carried out. Oxidation and dehydration of 1 gave furoxan 11 and furazan 2, respectively. Conversion of 2, 12, 13, and 11a, b into the target amine 3 by base-promoted reaction with hydroxylamine has been reported. © 1997 John Wiley & Sons, Inc.     

Reactions of Methyl 4-Aminofurazan-3-carboximidate with Nitrogen-Containing Nucleophiles

Methyl 4-aminofurazan-3-carboximidate reacts with aromatic amines and hydrazines to give the corresponding amidines and amidrazones. The reaction of the title compound with o-phenylenediamine yields 3-amino-4-(2-benzimidazolyl)furazan, and with acylhydrazines N²-acyl-4-aminofurazan-3-carbohydrazides are formed. The latter undergo thermal intramolecular cyclization with formation of 3-amino-4-(1,2,4-triazol-3-yl)furazan derivatives containing various substituents in position 5 of the triazole ring.     

Synthesis and Properties of Furazanyl-Substituted Acetylenes and Diacetylenes

Compounds of the acetylene and diacetylene series, containing a furazan ring, were synthesized by alkylation of 3,4-diaminofurazan and nucleophilic substitution of the nitro group in 3-amino-4-nitrofurazan under conditions of phase-transfer catalysis.     

Molecular Design and Performance Studies of 4-(1,2,4-Triazole-5-yl) Furazan Derivatives as Promising Energetic Materials

In this paper,eight 4-(1,2,4-triazole-5-yl) furazan (TZFZ) derivatives were designed,and the molecular configurations of TZFZ compounds were optimized by using the B3LYP/6-311+G*level.Meanwhile,the detonation performance,density,impact sensitivity,heat of formation and oxygen balance have been investigated.The results clearly and intuitively illustrate that the introduction of-NO_2 and coordination oxygen plays a pivotal role in increasing the density and heat of formation.In summary,the properties of these compounds are better than the traditional explosives RDX and TNT,especially the density and detonation pressure.Energetic evaluations showed that compounds B1 (P=36.73 GPa;D=8.98 km·s~(-1),ρ=1.88 g·cm~(-3))and B7 (P=38.51 GPa;D=9.17 km·s~(-1),ρ=1.90 g·cm~(-3)) could be seen as promising candidates of energetic insensitive compounds with remarkable performance.     

Synthesis of energetic compounds bearing a (3,4-dinitro-1H-pyrazol-1-yl)-NNO-azoxy group

Russian Chemical Bulletin - Energetic compounds containing a new explosophoric fragment, (3,4-dinitro-1H-pyrazol-1-yl)-NNO-azoxy group, and furazan rings linked by azo and azoxy bridges were...     

Decarboxylation and ring fragmentation reactions of sydnone N-oxides

4-Carboxylated sydnone N-oxides are readily decarboxylated by benzylation to give 2,4-dibenzylsydnone-N-oxides. Ring cleaveage results from their oxidation with bromine which leads to a nitrile N-oxide which is isolated as its furazan dimer.     

An experimental and theoretical study of the thermal stability of various organic azo compounds

Conclusions A study has been made of the kinetics of the thermal decomposition of various derivatives of nitrobenzene and furazan, attention being given to the relation between thermal stability and molecular energetics.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 313–317, February, 1978.The authors would like to thank L. I. Khmel'nitskii and T. I. Godovikova for having furnished the furazan compounds, and B. Ya. Teitel'baum and V. A. Byl'ev for a useful discussion of the results obtained here.     

多元曲线分辨结合在线红外用于3-氨基-4-氨基肟基呋咱的合成反应机理

利用红外光谱在线监测丙二睛、亚硝酸钠和盐酸羟胺合成3-氨基-4-氨基肟基呋咱的反应过程,采用多元曲线分辨-交替最小二乘法（MCR-ALS）、直观推导式演进特征投影法(HELP)等化学计量学方法对反应过程所获得的实时红外光谱数据矩阵进行解析,得到了各组分纯物质的浓度变化曲线和对应的红外光谱,并将多元曲线分辨 交替最小二乘法与直观推导式演进特征投影法的分析结果进行比较,得出可相互验证的一致结论,据此推出该反应合理的反应机理。 2种方法得到的反应物与生成物的光谱与原光谱的相似度近似于1,说明该解析方法具有准确性和可靠性。 结果表明,化学计量学结合红外光谱可有效的应用于3-氨基-4-氨基肟基呋咱合成过程的机理推断。     

Application and Development of 3,4-Bis(3-nitrofurazan-4-yl)furoxan (DNTF)

Russian Journal of General Chemistry - Energetic materials such as furazan and furoxan exhibit superior energy performance due to their high enthalpy of formation and density. Their research as...