Biomedical subjects
Publications and source records attributed to Michael A Hiskey.
The synthesis and properties of several new high-nitrogen materials with 3-amino-6-nitroamino-tetrazine (ANAT) as the anion are reported; all salts were fully characterized by IR and NMR spectroscopy, and elemental analysis.
Primary explosives are used in small quantities to generate a detonation wave when subjected to a flame, heat, impact, electric spark, or friction. Detonation of the primary explosive initiates the secondary booster or main-charge explosive or propellant. Long-term use of lead azide and lead styphnate as primary explosives has resulted in lead contamination at artillery and firing ranges and become a major health hazard and environmental problem for both military and civilian personnel. Devices using lead primary explosives are manufactured by the tens of millions every year in the United States from primers for bullets to detonators for mining. Although substantial synthetic efforts have long been focused on the search for greener primary explosives, this unresolved problem has become a "holy grail" of energetic materials research. Existing candidates suffer from instability or excessive sensitivity, or they possess toxic metals or perchlorate. We report here four previously undescribed green primary explosives based on complex metal dianions and environmentally benign cations, (cat)(2)[M(II)(NT)(4)(H(2)O)(2)] (where cat is NH(4)(+) or Na(+), M is Fe(2+) or Cu(2+), and NT(-) is 5-nitrotetrazolato-N(2)). They are safer to prepare, handle, and transport than lead compounds, have comparable initiation efficiencies to lead azide, and offer rapid reliable detonation comparable with lead styphnate. Remarkably, they possess all current requirements for green primary explosives and are suitable to replace lead primary explosives in detonators. More importantly, they can be synthesized more safely, do not pose health risks to personnel, and cause much less pollution to the environment.
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The synthesis, characterization, and energetic properties of diazido heteroaromatic high-nitrogen C-N compound, 3,6-diazido-1,2,4,5-tetrazine (DiAT), are reported. Its normalized heat of formation (NDeltaHf), experimentally determined using an additive method, is shown to be the highest positive NDeltaHf compared to all other organic molecules. The unexpected azido-tetrazolo tautomerizations and irreversible tetrazolo transformation of DiAT are remarkable compared to all other polyazido heteroaromatic high-nitrogen C-N compounds, for example, 2,4,6-triazido-1,3,5-triazine; 4,4',6,6'-tetra(azido)hydrazo-1,3,5-triazine; 4,4',6,6'-tetra(azido)azo-1,3,5-triazine; and 2,5,8-tri(azido)-1,3,4,6,7,9,9b-heptaazaphenalene (heptazine).
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
The synthesis and properties of several novel high-nitrogen materials based on nitroguanyl-substituted tetrazines are described. An optimized procedure provides straightforward access to these materials in multigram quantities.
Reactions between the Os(VI)-nitrido salts (e.g., trans-[Os(VI)(tpy)(Cl)(2)(N)]PF(6) (tpy = 2,2':6',2"-terpyridine), cis-[Os(VI)(tpy)(Cl)(2)(N)]PF(6), and fac-[Os(VI)(tpm)(Cl)(2)(N)]PF(6) (tpm = tris(pyrazol-1-yl)methane)) and the hydroxylamines (e.g., H(2)NOH and MeHNOH) and the methoxylamines (e.g., H(2)NOMe and MeHNOMe) in dry MeOH at room temperature give three different types of products. They are Os(II)-dinitrogen (e.g., trans-, cis-, or fac-[Os(II)-N(2)]), Os(II)-nitrosyl [Os(II)-NO](+) (e.g., trans- or cis-[Os(II)-NO](+)), Os(IV)-hydroxyhydrazido (e.g., cis-[Os(IV)-N(H)N(Me)(OH)](+)), and Os(IV)-methoxyhydrazido (e.g., trans-/cis-[Os(IV)-N(H)N(H)(OMe)](+), and trans-/cis-[Os(IV)-N(H)N(Me)(OMe)](+)) adducts. The products depend in a subtle way on the electron content of the starting nitrido complexes, the nature of the hydroxylamines, the nature of the methoxylamines, and the reaction conditions. Their appearance can be rationalized by invoking the formation of a series of related Os(IV) adducts which are stable or decompose to give the final products by two different pathways. The first involves internal 2-electron transfer and extrusion of H(2)O, MeOH, or MeOMe to give [Os(II)-N(2)]. The second which gives [Os(II)-NO](+) appears to involve seven-coordinate Os(IV) intermediates based on the results of an (15)N-labeling study.