Preparation and Characterization of Green High Energy Aminotetrazolium Dihydroborate and Closo-(B₁₂H₁₂)^-2 Salts

Substantial interest has developed in insensitive munitions (IM) - high energy compounds which are relatively stable to detonation. Ideally, the IM should be an environmentally friendly or “green” explosives as well, releasing neither smoke nor toxic gases when detonated. Other desired properties are high crystal density and heat of formation. Two class of compounds which would seem to answer all these criteria, are tetrazolium dihydroborate and closo-(B₁₂H₁₂)^-2 salts. The latter are rich in nitrogen and/or boron and produce primarily N₂ and boron oxides on oxidative decomposition. These materials are thermally stable and insensitive to electrical discharge, friction and impact. We have focused our efforts on the aminotetrazolium derivatives because of the high percentage of nitrogen atoms. A variety of nitrogen-rich and metal-free dihydrobis(1,2,4-triazolyl)borate, dihydrobis(5-aminotetrazolyl)borate 1 and 2 and closo- (B₁₂H₁₂)^-2 salts 3 of aminotetrazole derivatives were prepared as shown below.