Nitrate Esters and Nitramines

The most important color reaction for nitrate esters and nitramines is based on the formation of nitrite ions (NO2 ), upon reaction of these compounds with alkahs [31,32]. The nitrite ions are then detected by the classical Griess reaction [5,6]. 

Several pathways are known to take place in the reaction between nitrate esters and alkalis. The mechanism that leads to the formation of nitrite ions is an (X-ehmination abstraction of an CC-hydrogen atom, with the conversion of the nitrate ester to nitrite ion and the corresponding carbonyl compound [31] (Eq. (4))  

Other pathways in the reaction between nitrate esters and alkalis are simple hydrolysis and P-eHmination — the abstraction of a P-hydrogen atom simple hydrolysis (Eq. (5))  

Both pathways lead to the formation of nitrate (N03 ) ions. 

Nitrite ions can also be produced from nitrate esters by reducing the latter with zinc in acidic solutions [33] (Eq. (7))  

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Yinon, J. Mass Spectrometry of Explosives Nitro Compounds, Nitrate Esters, and Nitramines. Mass Spectrom. Rev. 

Alkahne hydrolysis, followed hy the use of sulfanihc acid and 1-naphtylamine, was the basis of a spot test for NG [37], as well as for several nitrate esters and nitramines, including NG, NC, tetryl, and RDX [38]. It is also a common spray for the detection of nitrate esters and nitramines on TLC plates [25, 29, 37, 39—41]. 

The DPA test is another common spot test for nitrate esters and nitramines [1, 3, 4, 50-55]. The reagent (1% DPA in concentrated sulfuric acid) is oxidized in the presence of these explosives, producing a deep blue color. 

A solution of the alkaloid brucine in concentrated sulfuric acid was reported [4, 38, 50] to give orange-red colors with nitrate esters and nitramines, probably by oxidation ofbmcine. 

A field test for the detection of TNT in contaminated soils (e.g., near ammunition plants) was based on the color reaction between TNT and alkalis (the Janowski reaction [7]) [26]. A few milligrams of the suspected soil are placed on filter paper and sprayed with 1 M NaOH acetone (1 1). A red color indicates the possible presence of TNT. Detection limits were reported to be 2-50 mg of TNT per 1 kg of soil, depending on the type of soil. The same group [55] used the oxidation of DPA in concentrated H2SO4 as the basis of a field test for nitrate esters and nitramines in soil. 

Fifer, R. L., Chemistry of Nitrate Ester and Nitramine Propellants, Fundamentals of Solid-Propellant Combustion (Eds. Kuo, K. K., and Summerfield, M.), Progress in Astronautics and Aeronautics, Vol. 90, Chapter 4, AIAA, New York, 1984. 

Nitroxyethyl Nitramine Plasticizers Nitroxy ethyl nitramine (NENA) plasticizers are a new family of energetic plasticizers which have emerged recently. These are effective plasticizers in energetic formulations, particularly in nitrocellulosic systems. NENAs contain both nitrate ester and nitramine functionalities and possess the general structure RN (N02).CH2.CH2.0N02 where R is methyl, ethyl, propyl, isopropyl, butyl and pentyl. 

According to Ref 10a, Hydrazoic acid molecules are linked into an infinite zigzag chain by N—H... N hydrogen bonds. Thus its high value of specific heat of vaporization is not unexpected. A fairly reliable Trouton constant of 23.5 eu for hydrazoic acid also suggests a non-ideal associated liquid. The other three azides in Table 8 have specific heats of vaporization similar to those of nitrate esters and nitramines... 

A considerable number of X-ray examinations of nitro compounds have been done over the last two decades. They will be given in the description of particular compounds. However, the following are reviews which should be mentioned X-ray analysis of aliphatic nitro compounds, nitrate esters and nitramines were described by Novikov and co-workers [7], nitramines by G. F. Wright [115], polynitroaromatic addition compounds by Hall and Poranski [116]. The X-ray... 

Nitrodesilylation. Silyl ethers and silylamines are converted to nitrate esters and nitramines, respectively, at about 0°. 

Fifer, R. L., Chemistry of Nitrate Ester and Nitramine Propellants, Fundamentals of Solid-Propellant Combustion, edited by Kuo,... 

Fifer RA, Chemistry of nitrate ester and nitramine propellants, in Fundamentals of Solid-Propellant Combustion, Vol. 90, Kuo KK, and Summerfield M, Eds., American Institute of Aeronautics and Astronautics Inc., New York, 1984, chap. 4. 

Those affecting the explosive nature directly, e.g., aliphatic and aromatic nitro groups, nitrate ester, and nitramine... 

Methyl nitrate and methyl nitramine have been chosen as models for two other important classes of energetic materials, nitrate esters and nitramines. The X-NO2 bond dissociation energy for the nitrate was calculated to be 38 kcal/mol and that of the nitramine 47 kcal/mol, consistent with the well known trends in stability and sensitivity for nitro, nitrate and nitramine compounds. Assuming that X-NO2 bond scission is rate determining, then neither nitrate nor nitramine decomposition is affected by the presence of ammonia. 

It should be emphasized that the routine use of GC-MS for post-explosion analysis is not without problems. Highly contaminated extracts from the debris often decrease the efficiency of the GC-MS analysis. This is especially true for some nitrate esters and nitramines, where a significant decrease in sensitivity has been observed. 

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