Explosion and Decomposition Characteristics of Hydrazoic Acid in the Gas Phase

Abstract

The formation of hydrazoic acid HN 3 is inherent to many azide processes due to the presence of small amounts of protic components in the reaction mixtures. Hydrazoic acid is an unstable component which may decompose violently. To ensure safe working conditions during the development or the production of azides, the lower decomposition limit (LDL) of this substance in a nitrogen atmosphere was determined using a 5-L explosion sphere. No decomposition could be observed for HN 3 concentrations below 10%. Moreover, the influence of solvent vapors was investigated to demonstrate that they can be used to inhibit the decomposition reaction of hydrazoic acid.

Development of a Lean Process to the Lead-Free Primary Explosive DBX-1

“…This process marks a significant advance over previously reported procedures that rely on isolation of the explosive intermediate 1 and manual charging of this material to a reactor, as well as purification of the NaNT prior to conversion to DBX-1. Our study of the improved process led to the a detailed analysis of the mass balance on this process and confirmation that 1 is the same composition as the recently reported solid state structure of Cu(5-NT) 3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 Table 3. Comparison of this work with previously disclosed processes for preparing DBX-1.…”

“…2 In addition to the environmental drawbacks, LA is also problematic because the azide anions can react with moisture in the presence of carbon dioxide to generate hydrazoic acid, a toxic and explosive low-boiling liquid. 3 Azide can also form extremely sensitive explosive complexes with other metals, such as copper. The unintended formation of copper azides in aging munitions with copper detonator shells has led to fatal accidents as bomb investigators and explosive ordinance disposal teams attempted to move these items.…”

A Scalable Metal‐, Azide‐, and Halogen‐Free Method for the Preparation of Triazoles

“…The formation of the triazoles derived from ammonia is of note since the dipolar cycloaddition of an alkyne with inorganic azide (NaN 3 ) represents a significant synthetic challenge. Furthermore, there are safety concerns due to the energetics of sodium azide and the risk of forming hydrazoic acid, [16] thus highlighting the benefits of this process. The ability to use our 3-component coupling procedure to access this class of heterocycle therefore provides an effective and particularly attractive complementary procedure to the AAC, which should be applicable to process chemistry.…”

Hydrazoic Acid and Azides

“…For further details of organic syntheses with HN 3 and NaN 3 , see Section 8.3. Acidification of sodium azide produces volatile, explosive and toxic hydrazoic acid (bp = 36°C) which is a weak Brønsted acid (pK a = 4.7) [6]. Particularly in the concentrated or pure state the liquid is very explosive.…”

“…Nowadays azides are not only applicable as detonators and propellants by releasing huge amounts of nitrogen gas [2] and for fine chemical syntheses, but also as bioorthogonal chemical reporters [3] and for drug design (e.g., zidovudine) [4]. Hydrazoic acid (HN 3 ) [5] itself has little industrial significance as it is highly toxic and explosive [6] (see Section 4.2) [7]; the most important salts are sodium azide and lead azide [1] as well as silver and barium salts. Especially the heavy metal azides tend to be highly explosive.…”