Energetic abilities of nitro derivatives of isomeric (pyrazol-3-yl)tetrazoles as components of solid composite propellants

Theoretical estimation of the efficiency factors of solid propellants whose components are CHNO compounds designed from various combinations of four structural motifs, namely pyrazole and tetrazole rings, nitro group, and trinitromethyl moiety, was performed. The positional isomerism was shown to have effect on the properties of the compounds and the energy characteristics of solid composite propellants (SCPs) on their basis. The use of these components in metal-free SCP compositions can allow one to achieve a specific impulse of 258–263 s, neither toxic HCl nor condensed products being produced upon their combustion, i.e., they are superior in energy and environmental indices to SCP formulations based on ammonium perchlorate.     

Computational study on energetic properties of nitro derivatives of furan substituted azoles

Density functional theory has been used to investigate geometries, heats of formation (HOFs), C-NO₂ bond dissociation energies (BDEs), and relative energetic properties of nitro derivatives of azole substituted furan. HOFs for a series of molecules were calculated by using density functional theory (DFT) and Møller–Plesset (MP2) methods. The density is predicted using crystal packing calculations; all the designed compounds show density above 1.71 g/cm³. The calculated detonation velocities and detonation pressures indicate that the nitro group is very helpful for enhancing the detonation performance for the designed compounds. Thermal stabilities have been evaluated from the bond dissociation energies. Charge on the nitro group was used to assess the impact sensitivity in this study. According to the results of the calculations, tri- and tetra-nitro substituted derivatives reveal high performance with better thermal stability.     

The effect of nitro groups on the structures and energetic properties of the derivatives composed of TATB and cubane

Based on the successful experience of synthesis of the TATB (1, 3, 5-triamino-2, 4, 6-trinitrobenzene) and cubane, we propose to consider their nitro derivatives combined by C–N bond as a series of high energy density compounds. First principles molecular orbital calculations have been used to investigate the structural and energetic properties, including the heat of formation, density, detonation performance, and impact sensitivity. Natural bond orbital analysis was carried out to investigate the influence of substituents on the electron delocalization. The results implied that the inclusion of nitro group will decrease the stability of cage skeleton and weaken the C–NO₂ bond. The calculated heats of formation, density, detonation velocity, and detonation pressure are positive and large. The results revealed that two of five derivatives have the close performance and sensitivity to those of CL-20, indicating that they may be explored as new potential high energy materials. Leave them with the notable value to dig out.     

Energetic polymers as binders in composite propellants and explosives

The principles behind the use of polymeric binders in composite propellants and explosives are described with emphasis on the properties which they should possess in order to satisfy the requirements for inclusion in a composition. The desirability of using energetic polymers as binders in terms of both performance and safety, and the problems associated with their preparation and properties, are discussed. The contributions of chemical synthesis within DRA to overcome these problems will be shown. Preparation of energetic polymers both by polymer modification and by polymerization of an energetic monomer is described. We have developed three energetic polymers: poly-3-nitratomethyl-3-methyloxetane (polyNIMMO), polyglycidyl nitrate (polyG-LYN) and nitrated hydroxy-terminated polybutadiene (NHTPB). Two of these (polyNIMMO and polyGLYN) have shown excellent properties in propellant and explosive formulations and proved that low-vulnerability, high-performance compositions are possible. The properties of the products from our work are compared with those of other groups and a glimpse of the future in this area is given to show the potential for new energetic polymers.     

Energetic potential of solid composite propellants based on CL-20-containing bimolecular crystals

The energetic potential of bimolecular crystals (BMCs) containing CL-20 as components of solid composite propellants (SCPs) was investigated. The experimental and calculated values of the standard enthalpies of formation are reported. The maximum heats of explosion, which correlate with the impact sensitivity, were calculated. The specific impulse values and the densities of SCPs based on an active binder, aluminum, and oxidizer (BMC + a small portion of ammonium dinitramide) were evaluated.     

The synthesis of malonimide derivatives as potential penicillin analogs

Malonimidoacetic acid derivatives (VIII, XIII) were synthesized as a potential penicillin analogs, hut they failed to inhibit the growth of bacteria when tested in vitro against a range of Gram-positive and Gram-negative microorganisms.     

Selective hydrogenation of nitro derivatives of hydroquinolines

By catalytic hydrogenation of p-nitrophenylhydroquinolines with 5-oxo- and 5-oxime functional groups in the presence of heterogeneous palladium complex catalysts, we have obtained the corresponding amino derivatives.Scientific-Research Institute of Chemistry at Saratov State University, Saratov 410026. Translated from Khimiya Geterotsildicheskikh Soedinenii, No. 8, pp. 1138–1140, August, 1995. Original article submitted June 8, 1995.     

Bromination of spiropyrans and reduction of their nitro derivatives

Depending on the nature of the nitrogen heteroring, either substitution only in the chromene ring (phenanthridine derivatives) or in both fragments of the molecule (indoline derivatives) occurs in the bromination of spiropyrans of the phenanthridine and indoline series with N-bromosuccinimide in low-polarity solvents, in which they are found in the cyclic form. The activity of the chromene fragment in both types of spiropyrans is approximately the same. The corresponding amino derivatives are formed in the catalytic reduction of spiropyran derivatives with a nitro group in the chromene ring in benzene solution. In alcohol solutions the nitro group and the 3–4 double bond of the chromene ring are hydrogenated simultaneously.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1320–1326, October, 1977.     

Synthesis and reactions of nitro derivatives of hydrogenated cardanol

3-n-Pentadecylphenol (hydrogenated cardanol) and its derivative 5-n-pentadecyl-2-tert-butylphenol can be nitrated using nitric acid in acetonitrile or methanol to give mono, di or trinitro products. 5-n-Pentadecyl-2-nitrophenol undergoes reductive carbonylation to give a benzoxazole-2-one derivative. An efficient catalytic oxidation reaction in the presence of MeReO₃ has also been studied.     

Synthesis of nitro and amino derivatives of benzothiacrown ethers

The condensation reaction of 1,2-bis(2-haloethoxy)-4-nitrobenzenes with acyclic α,ω-(oxa)alkanedithiols in the presence of alkali metal carbonates produced a series of nitrobenzodithiacrown ethers with macrocycles of different size. The structures of three ethers were established by X-ray diffraction. A new method was developed for the synthesis of nitrobenzomonothia-15-crown-5 ether. Nitro derivatives of benzodithiacrown ethers were tested as reagents for extraction of palladium(II), platinum(IV), and rhodium(III) from hydrochloric acid solutions. Extraction of Pd^II salts was found to be highly selective compared to that of Pt^IV and Rh^III salts. Benzodithia-15-crown-5 ether is the most efficient extractant for palladium(II). Reduction of nitrobenzothiacrown ethers with hydrazine hydrate in the presence of a platinum catalyst afforded their amino derivatives. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 958–966, May, 2007.     

An efficient reduction of nitro and bromine naphthalene derivatives

Russian Journal of General Chemistry - Reduction of 1,5-dimethoxy-4-nitronaphthalene by hydrazine hydrate was optimized in the course of current study. Influence of metals, temperature and solvents...     

Synthesis of naphthyridinone derivatives as potential antimalarials

In this paper we present the synthesis of 8-(4′-amino-1′methyl-butylamino)-5-(β,β,β-trifluoroethoxy)-1,6-naphthyridine ( 4 ), 8-(4′-amino-1′methylbutylamino)-6-methyl-1,6-naphthyricline-5-one ( 5 ), two 1-alkyl-3-(4′-amino-1′-methylbutylamino)-7-methyl-1,8-naphthyridin-4-ones ( 20a ) and 20b ), 3-(1′-amino-4′-methylbutyl-amino)-l-ethyl-7-methyl-l,8-naphthyridin-4-one (20c), and 4-(4′-diethylamino-1′-methylbutylamino)-7-methyl-1,7-naphthyridin-8-one ( 28 ). The compounds were evaluated for antimalarial activity in the Plasmodium berghei screen and found to be inactive.     

Tetraalkylammonium salts of naphthimide and its halo and nitro derivatives

Synthesis of tetraalkylammonium salts of naphthimide and its derivatives was studied     

芳香族硝基炸药感度和安定性的量子化学研究I.苯胺类硝基衍生物

运用HMO 和CNDO/2方法, 研究了二十多种苯胺类硝基衍生物的安定性. 随着分子中C-NO2 键级的增大, 其撞击感度减小丶热它定性增强. 以孤立双键为参考基准的离域能判据, 不能反映分子中基团位置对称定性的影响; 它的运用只能局限在基团相互位置影响不大的共轭体系中, 作为本系列化合物它性的影响; 它的运用只能局限在基团相互位置影响不大的共轭体系中.作为本系列化合物它定性的判据, C-NO2 键级较通常的离域能更为适用和直观; C-NO2 键级判据也符合炸药起爆和热分解机理, 且与Delpuech 的 判据相一致.     

Isomers and isomerization reactions of four nitro derivatives of methane

The nitro, nitrite, and aci-form isomers and the isomerization reactions of mono-, di-, tri-, and tetra-nitromethanes (NMs) were computationally investigated. The results show that the isomerization displacement of NO(2) by ONO groups is surprisingly thermodynamically favored for the di-, tri-, and tetra-NMs. The molecular stability decreases and the isomerization becomes easier by increasing nitro groups. The largest attraction among substitutes takes place through the central carbon atom in C(ONO)(4) and leads to its higher stability than the C(NO(2))(4) isomer. There is a concerted change of the CO-NO, C-ONO, and CON-O bonds in the nitrite isomers, that is, the weakened CO-NO bond is accompanied with the strengthened C-ONO and CON-O bonds, and vice versa. We only succeeded in finding two tight transition states of isomerization reactions from NO(2) to ONO in the mono- and di-NMs, whereas isomerization reactions to the aci-forms through an intramolecular hydrogen transfer can always be found.     

Thermodynamic properties of nitro derivatives of diphenyl ether and biphenyl

The heat capacity of 4,4′-dinitrodiphenyl ether and 4-nitro-4′-biphenylcarboxylic acid were measured by adiabatic calorimetry (AC) in temperature ranges of 8–372 K and 10–372 K, respectively. The heat capacity of 4,4′-dinitrodiphenyl ether in the temperature range 323–500 K, the thermodynamic properties of fusion, and the purity of the ether were measured by differential scanning calorimetry (DSC). The main thermodynamic functions in the temperature range 5–370 K were calculated for both compounds using the heat capacities of adiabatic calorimetry. Related thermodynamic functions of 4,4′-dinitrodiphenyl ether in the temperature range 370–500 K were calculated on the basis of DSC data.     

Pyrrolocoumarin derivatives as potential photoreagents toward DNA

A number of new methyl derivatives of linear and angular pyrrolocoumarins were synthesized by direct Fischer's indole synthesis. In the same way some linear 2H,10H-pyrano[2,3-b]carbazol-2-one and angular 2H,7H-pyrano[3,2-c]carbazol-2-one were prepared. The synthesis was performed starting from the 4-methyl-7-aminocoumarin and methyl groups were introduced into positions which look most promising for the photoreactivity of the compounds toward DNA.     

4'-Acetamidochalcone derivatives as potential antinociceptive agents

Nine acetamidochalcones were synthesized and evaluated as antinociceptive agents using the mice writhing test. Given intraperitoneally all the compounds were more effective than the two reference analgesic drugs (acetylsalicylic acid and acetaminophen) used for comparison. N-{4-[(2E)-3-(4-nitrophenyl)prop-2-enoyl]phenyl}acetamide (6) was the most effective compound and was therefore selected for more detailed studies. It caused dose-related inhibition in the writhing test, being about 32 to 34-fold more potent than the standard drugs. It was also effective in the second phase of the formalin test and the capsaicin test. These acetamidochalcones, especially compound 6, might be further used as models to obtain new and more potent analgesic drugs.