Kinetics and mechanism of thermal decomposition of 2-substituted 5,5-dinitro-1,3-dioxanes

Thermal decomposition of 2-substituted 5,5-dinitro-1,3-dioxanes in melt and in solution follows a homolytic mechanism with initial dissociation of the C-N bond. The reaction in solution is accompanied by oxidation of the initial compound with nitrogen dioxide formed as a result of decomposition. The rate of decomposition weakly depends on the substituent in position 2 of the heteroring. On the whole, the C(NO₂)₂ moiety in 1,3-dioxanes is less stable than in alkanes due to conformational features of the heteroring.Translated from Zhurnal Obshchei Khimii, Vol. 74, No. 10, 2004, pp. 1702–1705.Original Russian Text Copyright © 2004 by Stepanov, Kruglyakova, Astakhov, Golubtsova.This revised version was published online in April 2005 with a corrected cover date.     

5‐Nitro‐2‐nitromethyl‐2H‐1,2,3,4‐tetrazole

The mol­ecule of the title compound, C₂H₂N₆O₄, consists of three planar fragments, namely a tetrazole ring, a nitro­methyl group and a nitro group. The nitro group and the tetrazole cycle are arranged in the same plane, but the planar nitro­methyl group is located nearly orthogonal to this plane. The mol­ecules are packed in the crystal via van der Waals interactions.     

3-Nitro-1-nitromethyl-1H-1,2,4-triazole

The title compound, C₃H₃N₅O₄, consists of three planar fragments twisted in relation to each other, namely a triazole ring, a nitro­methyl­ene group and a nitro group. Molecular conformation analysis shows that the first stage of thermal decomposition is a breakage of the H₂C—NO₂ bond. There are essential conformational differences in the mol­ecule in comparison with semi-empirical calculations.     

Wilson Loops in Exact Holographic RG Flows at Zero and Finite Temperatures

Theoretical and Mathematical Physics - We study rectangular timelike Wilson loops at long distances in the exact renormalization group flow in the context of the holographic duality. We consider...     

Exact solutions in gravity with a sigma model source

We consider a D-dimensional model of gravity with non-linear “scalar fields” as a matter source. The model is defined on the product manifold M, which contains n Einstein factor spaces. General cosmological type solutions to the field equations are obtained when n − 1 factor spaces are Ricci-flat, e.g. when one space M ₁ of dimension d ₁ > 1 has nonzero scalar curvature. The solutions are defined up to solutions to geodesic equations corresponding to a sigma model target space. Several examples of sigma models are presented. A subclass of spherically symmetric solutions is studied and a restricted version of “no-hair theorem” for black holes is proved. For the case d ₁ = 2 a subclass of latent soliton solutions is singled out.