Energetic materials have been used for nearly two centuries in military affairs and to cut labor costs and expedite laborious processes in mining, tunneling, construction, demolition, and agriculture, making a tremendous contribution to the world economy. Yet there has been little advancement in the development of altogether new energetic motifs despite long-standing research efforts to develop superior materials. We report the discovery of new energetic compounds of exceptionally high energy content and novel polymeric structure which avoid the use of lead and mercury salts common in conventional primary explosives. Laboratory tests indicate the remarkable performance of these Ni- and Co-based energetic materials, while DFT calculations indicate that these are possibly the most powerful metal-based energetic materials known to date, with heats of detonation comparable with those of the most powerful organic-based high explosives currently in use.

Second-generation cobalt and zinc coordination architectures were obtained through efforts to stabilize extremely sensitive and energetic transition-metal hydrazine perchlorate ionic polymers. Partial ligand substitution by the tridentate hydrazinecarboxylate anion afforded polymeric 2D-sheet structures never before observed for energetic materials. Carefully balanced reaction conditions allowed the retention of the noncoordinating perchlorate anion in the presence of a strongly chelating hydrazinecarboxylate ligand. High-quality X-ray single-crystal structure determination revealed that the metal coordination preferences lead to different structural motifs and energetic properties, despite the nearly isoformulaic nature of the two compounds. Energetic tests indicate highly decreased sensitivity and DFT calculations suggest a high explosive performance for these remarkable structures.

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Monolithic yttrium-based aerogels and xerogels were prepared by the epoxide addition method. The effects of changing both the gelation solvent and the yttrium salt precursor in the reaction were investigated. The porous morphology of the resulting aerogel materials was investigated using gas adsorption/desorption analysis, scanning electron microscopy and transmission electron microscopy. The solvent in which the aerogels were formed was found to significantly impact the porous structure and physical morphology of these materials. The counterion used to synthesize the gels also had a profound impact on gel formation. The chloride salt precursor gave successful gels while the nitrate salt gave only precipitates. The yttrium-based xerogels synthesized were annealed at various temperatures in static air, nitrogen, and oxygen atmospheres. The annealed materials were analyzed using powder X-ray diffraction. The amorphous as-synthesized material is found to form the stoichiometric yttrium oxide by way of an oxygen deficient yttrium oxide species which is black in color.

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