High Energy Density Materials

Abstract : Synthetic pathways to the nitroazoxyamine, pentazole-N-oxide, and triazanitrate anions have been explored at a fundamental level. The reaction of nitrene equivalents such as organic azides, N-haloamines, N-acyl hydroxylamines N,O-diacyl hydroxylamines, and amides in the presence of lead tetra-acetate or phenyliodine diacetate, acting on N,N dialkylnitrosoamines in an attempt to generate alkylazoxyamines have all been examined. Initial results were not encouraging; in response to this, the N,N-dialkylnitrosoamine was silylated, methylated, and acylated to give 1, 1-dialkyl-2silyloxy diazenium cation and its analogues. These cations were reacted with a wide array of nucleophillic nitrene equivalents such as fluoronitramide anion or monobromo-tert, butylamme; again, no azoxy amine was observed. Intramolecular versions of the above mentioned methodologies were contrived; the appropriate intermediates were synthesized, characterized, and subjected to a variety of conditions designed to effect the intramolecular synthesis of the alkylazoxyamine, a useful precursor to the heretofore unknown nitroazoxyamine (diazanitrate). Still, no obvious evolution of the desired azoxyamine was observed. Many variations remain to be explored. One clear success in this program was the invention of HYDROXYNITROUREA, a high density oxidizer with potential use as a replacement for perchiorate. Kilogram quantities were made and tested commercially; it tended to burn too fast at elevated pressures. The ammonium salt of HNU shows much promise as a bum rate attenuator, and this is presently being explored.