Synthesis and characterization of high energy-density N-nitramino, geminal dinitro and geminal difluoramino propellants

Propellants and explosives are composed of energetic materials that produce high temperature and pressure through combustion phenomena. They have both important civilian and military applications. An abbreviated introduction reviews the fundamental properties of the different chemical compounds used for explosives and propellants. Briefly, these include heats of formation of reactants and products, formulation of propellants, oxygen balance, importance of density and specific impulse considerations. A second aspect is devoted to an examination of the many synthetic methods employed to prepare the novel modern high energy-density materials currently being investigated on a world-wide basis. Attention is drawn to the increased energy output of these new materials, their improved environmental attributes as well as their improved insensitive munitions characteristics. Based on predictions of crystal structure and density considerations a number of target compounds have been identified as having expected physical and performance properties worthy of further investigation.; In a third phase, the cyclodimerization of p-toluenesulfomamide and 3-chloro-2-(chloromethyl)-1-propene to prepare N,N'-bis(4-methylbenzenesulfonyl)-3,7-bis-(methylene)tetrahydro-1,5-diazocine (47a) and its ozonation to the corresponding 3,7-dione ( 48a) are described. Unusual transannular cyclizations initiated by lithium aluminum hydride treatment or bromination of 47a and oxidative coupling of the dioxime derived from 48a are described. These reactions lead, respectively, to the following derivatives of the little-studied 3,7-diazabicyclo[3.3.0] octane ring system: 1,5-dimethyl-3,7-diazabicyclo[3.3.0] octane (53), N,N'-bis(4-methylbenzenesulfonyl)-1,5-bis(bromo-methyl)-3,7-diazabicyclo[3.3.0] octane (57), and N,N'-bis(4-methylbenzenesulfonyl)-1,5-dinitro-3,7-diazabicyclo[3.3.0]octane (61). Reaction of the dibromide (57) with the nucleophiles, sodium sulfide, sodium oxide, and sodium p-toluenesulfonamide conveniently delivers the corresponding novel 3,7,10-triheterocyclic[3.3.3]propellanes.; Finally, the syntheses of new 3,3-dinitro derivatives of the 1,5-diazocine ring system are described. Highly deactivated precursor ketones, 7,7-dinitro-1,5-bis(2- and 4-nitrobenzenesulfonyl)hexahydro-1,5-diazocin-3-ones ( 92a and 92b), have been difluoraminated to the corresponding gem-bis(difluoramino) diazocines (93a and 93b). The 1,5-bis(4-nitrobenzenesulfonyl)diazocine derivative (93a) undergoes N-nitrolysis with the protonitronium reagent formed in the system nitric acid - trifluoromethanesulfonic acid - antimony pentafluoride to produce 3,3-bis(difluoramino)octahydro-1,5,7,7-tetranitro-1,5-diazocine (TNFX ), containing nitramine, gem-dinitro and gem-bis(difluoramino) structural components. TNFX has been fully characterized by NMR spectroscopy, high resolution mass spectrometry and X-ray crystallography.