To a first approximation, the shockwave pressure and specific impulse of a propellant are proportional to the square of the propellant's density. Molecules with cubane and adamantine structures are thus particularly appealing as potential energetic materials not only because their strain energy contributes to energy content, but also because they are unusually dense. R.D. Gilardi and J. Karle discuss the 3-dimensional crystal structure of real and hypothetical materials, such as 1,3,5,7-tetranitrocubane, which has a density comparable to RDX (1.83 vs. 1.81 g/cm3), and hexanitrohexa-aza-adamantane, which is predicted to be 1.5 times as powerful as RDX. Anex et al. describe their studies of the decomposition of 1,3,3-trinitroazetidine, another highly strained molecule related to the familiar 6- and 8-membered cyclic nitramines, using multiphoton infrared photofragmentation spectroscopy. Other chapters investigate the dissociation of haloaromatics using picosecond X-ray diffraction, and computer aided design of monopropellants with properties superior to HMX (1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane).
The articles by A.T. Nielsen and G.A. Olah, discussing the chemistry of caged azapolycyclics such as polyazaadamantanes and polyazawurtzitanes, and the more mundane chemistry of nitration reactions, respectively, give an excellent overview of the chemistry of energetic materials. Inorganic chemistry receives short shrift, with only one short chapter on caged lanthanide and alkaline-earth metallacarboranes. The relevance of these molecules to energetic substances is not made clear.
These highly specialized research articles will provide little insight for readers curious about the physical properties of highly energetic materials or the general principles of explosives technology. There is no discussion of peroxides, C-nitro compounds such as trinitrotoluene, or mixtures such as gunpowder, which participates in a very complex series of chemical reactions. However, the articles provide a fascinating glimpse into a specialized branch of the organic chemistry of nitrogen-containing compounds and the exotic instrumentation needed to study their rapid reactions.