Strained and Cage Compounds

Considerable current interest and sustained research efforts of some groups in the USA and other countries have been aimed at the synthesis and chemistry of strained energetic compounds. According to Marchand and co-workers, polynitro polycyclic cage compounds are important members of this class [110]. 

On the other hand, Dudek et al. found that the impact sensitivity (h50% ) of e CL-20 28 cm is comparable to that of [5-HMX (h50% = 30 cm) [124]. Agrawal et al. have not only given impact sensitivity of CL-20 but also the mechanism of initiation on impact leading to its detonation. This is in line with the mechanism of initiation by hot spot formation on impact followed by detonation similar to other secondary explosives [125]. 

A critical appraisal of all synthetic routes of CL-20 vis-a-vis yield, purity and ease of scaling-up had been carried out by Sanderson and coworkers [126] and the gist of their conclusions is  

1) The original route to synthesize CL-20 from the precursor tetraacetyldinitroso isowurtzitane (TADNIW) may give very pure CL-20 but it is not the most economical route [127]. In this method, it is either necessary to isolate and handle a nitrosamine or to do one-pot nitrosation followed by nitration the latter is possible in the laboratory but does not appear practical for bulk production. 

3) CL-20 had also been synthesized with another precursor, that is, tetraacetal 

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