In this work, the electrooxidation as environmentally clean technology has been studied to the degradation of Mordant Blue 13 azo dye (MB13) using boron-doped diamond (p-Si/BDD) and oxide ruthenium titanium (Ti/RuTiO (DSA)) anodes in various water matrices: distilled water (DW), hot tap water (HTW), and simulated wastewaters with (SWS) and without surfactant (SW). The influence of experimental parameters, such as current density, initial dye concentration, electrolysis time/specific charge, and pH on the MB13 degradation rate, current efficiency, and energy consumption, has been determined. The enhanced rate of both color and chemical oxygen demand (COD) removal in sulfate aqueous solutions with BDD was observed, which indicates that sulfate (SO) radicals along with OH ones might be responsible for the degradation process. The MB13 decolorization process obeyed a pseudo-first-order reaction kinetics with the apparent rate constant from 7.36 × 10 min to 4.39 × 10 min for BDD and from 9.2 × 10 min to 2.11 × 10 min for DSA depending on the electrolysis conditions. The effect of water matrix on the decolorization and COD removal efficiency has been evaluated. Inorganic ions, mordant salt, and surfactant contained in simulated effluents decelerated the COD decay compared to DW and HTW for the both anodes; meanwhile, they differently affected the discoloration process. A comparison of the specific energy consumption for each electrocatalytic material under different experiment conditions has been made. The BDD electrode was more efficient than the DSA to oxidize the MB13 dye in all kinds of water.

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The molecule of the title compound, C(2)H(2)N(6)O(4), 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.

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 C3N 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(NO 2 ) 2 moiety in 1,3-dioxanes is less stable than in alkanes due to conformational features of the heteroring.We examined thermal decomposition of 2-substituted 5,5-dinitro-1,3-dioxanes I3VII in the liquid phase with a view to elucidate the effect of the 2-substituent on the rate and mechanism of the process. : : ; =; ; 9 ; < < 9 O O d e h O 2 N O 2 N R I!VII I, R = H; II, R = CH 3 ; III, R = C 6 H 5 ; IV, R = p-O 2 NC 6 H 4 ; V, R = 4-furoxan-5-yl; VI, R = CH 3 N(NO 2 )CH 2 CH 2 ; VII, R = CH 3 C(NO 2 ) 2 CH 2 CH 2 .Interest in this class of compounds originates from their possible practical application as components of high-energy compositions for various purposes [1].Thermal decomposition of compounds I3IV and VII in melt is accompanied by autoacceleration and is characterized by S-like kinetic curves, whereas geminal dinitroalkanes are known to decompose in the gas phase according to first-order kinetics [2]. The initial rate of decomposition of I3IV does not change with variation of m/V (the ratio of the sample weight to the reaction volume) and S/V (the ratio of the reactor surface to its volume). Gaseous decomposition products accelerate substrate decomposition. Qualitative mass-spectrometric analysis of the reaction mixtures showed that the major gaseous products of decomposition of compounds I, II, and VII (conversion 13325%) are NO 2 , NO, N 2 O, CO, CO 2 , and H 2 O. Among these, the most reactive is nitrogen dioxide; therefore, we examined its effect on the character and rate of decomposition of compound I (Fig. 1).It is seen that the rate of decomposition increases as the concentration of nitrogen dioxide increases; however, the shape of the kinetic curve does not change. We can conclude that the acceleration of the decomposition of 2-substituted 5,5-dinitro-1,3-dioxanes results from reaction of the substrate with nitrogen dioxide liberated during the process. This conclusion was confirmed by experiments performed with dinitrodioxanes I3VII in dilute (235 wt %) solutions in such relatively inert solvents as dibutyl phthalate and 1,3-dinitrobenzene. Under these conditions, molecules of the substrate are isolated from each other and from decomposition products, while the solubility of nitrogen dioxide at 1903210oC is low. Here, the decomposition process followed first-order kinetcs. The rate of decomposition did not depend on the substrate concentration (238 wt %) and dielectric constant of the solvent (e = 6.1 and 20.6, respectively). These data suggest that the decomposition of dinitrodioxanes I3VII involves a nonpolar activated complex typical of radical and molecular mechanisms.

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The title compound, C(3)H(3)N(5)O(4), 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 H(2)C-NO(2) bond. There are essential conformational differences in the molecule in comparison with semi-empirical calculations.

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