Nitramines, nitramides and nitrimines as explosives

The energetic nature of the N-NO2 group means that At-nitro-based explosives are some of the most powerful explosives available and these have largely superseded aromatic C-nitro compounds for military applications. Many nitramines exhibit high brisance and high chemical stability in combination with a favourable low sensitivity to impact and friction compared to nitrate ester explosives of similar power. 

The chemical properties of primary and secondary nitramines are important in relation to their use as explosives. Primary nitramines contain acidic hydrogen in the form of —N//NO2 and, consequently, in the presence of moisture, primary nitramines corrode metals and form metal salts, some of which are primary explosives. This is one reason why powerful explosives like methyinitramine (1) have not found practical use. Ethylenedinitramine (EDNA) (2) suffers from similar problems but its high brisance (VOD 8240 m/s, d = 1.66 g/cm ) and low sensitivity to impact have seen it used for some applications. 

In contrast, secondary nitramines have no acidic hydrogen and often exhibit a high chemical stability in combination with acceptable thermal and impact sensitivity. Consequently, secondary nitramines are often the explosives of choice for military use. 

Although RDX and HMX are adequate for military applications, they are by no means perfect. The risk of premature detonation increases when such explosives are used in shells for high calibre guns due to the higher set-back force. Also of concern is the risk of catastrophic 

A number of important explosives contain nitramino functionality in conjunction with nitrate ester or C-nitro functionality. A-Nitrodiethanolamine dinitrate (DINA) (7) is a powerful explosive which can be melt-cast into charges. A,2,4,6-Tetranitro-A-methylaniline (tetryl) (8) exhibits high brisance (VOD 7920 m/s, d = 1.73 g/cm ) and has found application in both detonators and boosters, in addition to being a component of some composite high explosives. 

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