Synthesis and crystal structure of beta-hexanitrohexaazaisowurtzitane

A polycyclic caged compound with high strain-hexanitrohexaazaisowurtzitane (HNIW)-has been synthesized via a three-step reaction: condensation, hydrog enolysis debenzylation and nitrolysis, starting with benzylamine and glyoxa l. HNIW is the most powerful high energy density compound (HEDC) ever teste d. beta-HNIW possesses a caged structure consisting of two five-membered ri ngs and one six-membered ring with a nitro group attached to each of the si x bridging nitrogens. The nitro group lies basically within a plane. The le ngths of C-C bonds of beta-HNIW range from 0.156 nm to 0.159 nm, 0.002-0.00 5 nm longer than the sp(3) CC bond. The beta-HNIW's crystal belongs to orth orhombic system and space group Pca2(1) with parameters: a = 0.9670 (2), b = 1.1616 (2), c = 1.3032 (3) nm; V=1.4638(5) nm(3), Z=4; D-c=1.989 g/cm(3) and D-m=1.982 g/cm(3).