S. A. Vozchikova

New method for the synthesis of 1,2,3-triazole 1-oxides

A general method is proposed for the synthesis of 1,2,3-triazole 1-oxides using 3,4-dinitro- or 4-amino-3-nitrofuroxanes.

Reactions of 2,4-Disubstituted 5-Nitro-1,2,3-triazole 1-Oxides. 4. Dealkylation of 2-Substituted 4,5-Dinitro-1,2,3-triazole 1-Oxides

The N-dealkylation of 2-alkyl or 2-benzyl-substituted 4,5-dinitro-1,2,3-triazole 1-oxides has been studied. Conditions have been found for N-de-tert-butylation and 4-amino-5-nitro-1,2,3-triazole 1-oxide has been synthesized for the first time.

Synthesis and nucleophilic substitution reactions of 3,4-dinitrofuroxan

Abstract3, 4 Dinitrofuroxan and 3-nitrofuroxans derived from it by functional group substitution at position 4 have been synthesized for the first time.

A new crystalline HMX polymorph: ɛ-HMX

A new crystalline HMX polymorph, ɛ-HMX, was obtained. ɛ-HMX crystals were studied by X-ray structure analysis, optical microscopy, and differential scanning calorimetry. Their space group is P21/c. The unit cell parameters are a = 21.799(3) Å, b = 10.913(2) Å, c = 10.819(2) Å, and β = 97.43(2)°, V = 2552.15 Å3, Z = 4. ɛ-HMX molecules are not equivalent in crystals and have chair conformations. The heat of the polymorphic transition of ɛ-HMX into the δ-polymorph was measured. The transition occurred with the intermediate formation of β-HMX. The dependence between the heats of polymorphic transitions and the densities of crystals of various HMX polymorphs was demonstrated. The character of this dependence was to a substantial extent determined by the type of HMX molecule conformation.

Recyclization of substituted furoxans into 1,2,3-triazol-1-oxide derivatives

The effect of the position and nature of substituents on the recyclization of substituted furoxans has been established.

Kinetics of reversible polymorphic transitions in high-energy compounds. Phase transformations in octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine

The kinetics of reversible phase transitions (PTs) in various polymorphs (α, β, γ, δ, and ɛ) of polycrystalline octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) is investigated by means of differential isothermal and scanning calorimetry. The rate of the β → δ PT is limited by the nucleation process occurring during the induction period. In a general case, the distribution density for the induction times is a superposition of continuous and discrete functions. The reverse δ → β PT obeys the first-order kinetic law. The effects of mechanical exposure on the kinetics and the PT products of the different polymorphs of HMX is investigated by FTIR spectroscopy.

Reactions of 2,4-Disubstituted 5-Nitro-1,2,3-triazole 1-Oxides. 3. Destructive Nitration of Nitrosubstituted 2-Acetonyltriazole Oxides and Azotriazole Oxides

We have studied destructive nitration of acetonyltriazole oxides and azotriazole oxides to the corresponding trinitromethyl derivatives.

Reactions of 2,4-disubstituted 5-nitro-1,2,3-triazole 1-oxides. 2. Oxidation of 2-substituted 4-amino(alkylamino)-5-nitro-1,2,3-triazole 1-oxides

The oxidation of substituted aminonitrotriazole oxides to the corresponding dinitro derivatives of triazole and azotriazole oxides has been studied.

Kinetics of reversible polymorphic transition in energetic materials. Phase transitions α → β and β → α in 1,1-diamino-2,2-dinitroethylene

Differential scanning calorimetry and isothermal calorimetry are used to study the kinetics of the α → β polymorphic transformation (PT) in 1,1-diamino-2,2-dinitroethylene (DADNE). The kinetics of the β → α PT in DADNE is investigated by infrared spectrophotometry. The α → β phase transition is described by the first-order autocatalysis equation. The activation energy and the rate constant are determined. The rate of the β → α PT is described by the kinetic law for two parallel first-order processes. The rate constants for these processes are obtained.

Relationship between oxosilicate niobium mineralization and organic matter in alkaline pegmatites of the Khibiny pluton, Kola Peninsula

In alkaline pegmatites of the Khibiny pluton niobium oxosilicates with (Nb + Ti)/Si ≥ 1 and Nb > Ti occur in intimate fine intergrowths with endogenic organic matter, which makes it possible to assume a genetic relationship between them. Such intergrowths from pegmatites of Mounts Kukisvumchorr and Koashva have been studied by electron microscopy, electron microprobe, IR spectroscopy, and exclusion chromatography. Unsaturated hydrocarbon groups, including aromatic ones, and carboxylate groups are prevalent in the organic matter intergrown with the niobium oxosilicates. The molecular weight distribution in the part of the bitumen soluble in tetrahydrofurane is polymodal, probably due to its formation as a result of parallel reactions on several catalytic centers of polymerization.