Über zwei analytisch wichtige Reaktionen der Stickstoff‐wasserstoffsäure

Hydrazoic Acid and Its Inorganic Derivatives.

“…Potassium chlorate and manganese dioxide react only slightly, while potassium permanganate and persulfates are more vigorous in their action. Complete and rapid reaction is obtained only when the ceric salts (207), hypochlorous acid (184), or nitrous acid (206,207,230,169) are used. Oxidation with complete conversion of the azide group into molecular nitrogen is obtained only in the case of ceric salts, in accordance with the equation:…”

“…Either the volume of nitrogen (207) evolved is measured directly, or the excess of standard ceric salt solution determined iodimetrically (155). In the case of hypochlorous acid and of nitrous acid, condensation takes place to give in the first instance chlorazide, and in the second case nitrosylazide (207), which decomposes into nitrogen and nitrous oxide. HN3 + HOC1 -» H20 + C1N3 hno2 + hn3 -> non-n2 + h2o -> n2 + n2o Dennis and Browne (80,81) investigated potassium permanganate as an oxidizing agent in the hope that it might lead to a quantitative method for the determination of hydrazoic acid.…”

“…In carrying out the analysis of azides according to equation 1, the sodium nitrite and the azide are allowed to react in a solution made acid with dilute sulfuric acid and the resulting gases are collected and measured (206,207,229,250). Since nitrous oxide is appreciably soluble in water, results are apt to be low.…”

Kinetics and stoichiometry of the reaction between manganese(III) and hydrazoic acid in acid perchlorate solution

“…The reactions of azide species (HNs and/or N3-) with metal ions have been found to produce stoichiometric quantities of molecular nitrogen only for the cases of Ce(IV) (in H2S04), 6 MnnlEDTA(OH2) ~(pH 3.0-5.0), 7 and Co(III) (in HC104).8 Kinetic studies of the latter two reactions have led to the postulation of the unimolecular decomposition of coordinated metal-azide species to give a neutral N3 radical intermediate. The radical species H2N8+ has been postulated as an intermediate in the oxidation of HNj by Mn(III) at low excesses of hydrazoic acid.9 Although the free energy decrease for the oxidation of azide to nitrogen by ferric ion is quite large (96 kcal/mol),10 this reaction does not tion of acrylonitrile, giving evidence for the oxidation of the complexed azide via a free-radical mechanism.11 Azide ion forms reasonably stable complexes with metal ions.2,12 The azide group, being a highly conjugated, symmetrical system, is an excellent bridging ligand and participates as such in inner-sphere electrontransfer reactions in which the formation of the bridged intermediate (rather than the actual electron transfer) is the rate-determining step.1314…”

AZIDO-DITHIOCARBONIC ACID IV. AMMONIUM AND TETRAMETHYLAMMONIUM AZIDO-DITHIOCARBONATES; TETRAMETHYLAMMONIUM THIOCYANATE1,2

“…In connection with a study of the power of solution and ionization of various lionaqueous solvents towards binary salts, Walden7 prepared tetramethylammonium thiocyanate (1) by heating methyl thiocyanate with a solution of trimethylamine. During the current research this method has been compared with two others, by which the salt is obtainable either (2) by prolonged boiling of an aqueous solution of tetramethylammonium azido-dithiocarbonate, until quantitative decomposition into the thiocyanate has occurred, or (3) by bringing together tetramethylammonium trinitride6 and carbon disulfide in alcoholic solution and boiling under the reflux condenser until the reaction has proceeded to completion.8 The third method was found most convenient.…”