|About the Book|
Recently the 1,3,5-triazine ring system has shown promise as a simple, stable, and inexpensive precursor for the synthesis of novel energetic materials. Synthetic work has resulted in several energetic compounds which have desirable properties.MoreRecently the 1,3,5-triazine ring system has shown promise as a simple, stable, and inexpensive precursor for the synthesis of novel energetic materials. Synthetic work has resulted in several energetic compounds which have desirable properties. Although the synthetic chemistry surrounding triazines has been explored for nearly a century, development of highly complex multi-ring heterocyclic and nitrogen linked triazine moieties has only just begun.-In a search for novel energetic materials azo-linked bis triazines were pursued. Herein the thermal decomposition of 14 simple triazines and 16 hydrazo or azo-linked bis triazines were studied using mass spectrometry, gas chromatography, and differential scanning calorimetry. Decomposition was complete at temperatures far above the decomposition onset. Lower temperatures provided insight into the stability of the functional groups pendant to the triazine rings. Decomposition gases were identified by chromatography- they indicated little degradation of the triazine rings. The s-triazine ring system appears very stable, resisting decomposition up to 550°C while its substituents undergo isolated chemistry. The azo or hydrazo linkage does not appear to be a trigger for the decomposition and nitrogen release is easily correlated between amino, hydrazino, and azido substituents.-Hydrogenation of azo bonds with hydrazine, mono-substituted hydrazine, and hydrazobenzene was studied with selected diazene compounds under oxygen-free conditions. The reactions proceed rapidly and in high yield in several solvents. The stoichiometry of the reactions suggests that all N-H hydrogens are efficiently delivered regardless of reaction time. While the reduction process is accompanied by the evolution of nitrogen gas in the case of N2H4, the intermediacy of diimide could not be confirmed by standard trapping experiments. Evidenced by the difference in reactivity from azoarenes, electron-poor diazenes appear to offer a yet undescribed mechanistic pathway to proton abstraction which may be developed as a synthetic tool.-Acid catalyzed nitration has been examined using a variety of novel nitration agents: guanidine nitrate, nitroguanidine, and ethylene glycol dinitrate. Reactions with activated or deactivated aromatics proceed rapidly and in high yield- however, regioselectivity was similar for all nitrating agents examined. The synthetic advantages of liquid EGDN include high solubility in organic solvents, strong nitration activity, and ease of preparation.