Coloring Properties of Various High-Nitrogen Compounds in Pyrotechnic Compositions

Strontium salts are widely used in red flame pyrotechnic compositions, usually combined with perchlorate salts as oxidizer. The potential environmental impact of perchlorate could be avoided by using high-nitrogen compounds. Therefore, the following nitrogen-rich strontium salts were prepared and characterized: strontium tetrazolate pentahydrate (1), strontium 1-methyl-5-nitriminotetrazolate monohydrate (2), and strontium 1-(2-chloroethyl)-5-nitriminotetrazolate monohydrate (3). Their combustion behavior and both color intensity and purity were investigated in pyrotechnics. These results were compared with the US Army in-service signal formulation. Pyrotechnic compositions which are used for producing green flame colors contain barium salts, usually highly water-soluble and toxic barium nitrate, Ba(NO3)(2). In this research project copper-based colorants with energetic anions or ligands were developed. The compounds diammine bis(tetrazolato)amine copper(II) (4), diaqua copper(II) di(1-methyl-5-aminotetrazole) nitrate (5), diaqua copper(II) tetra(1-methyl-5-aminotetrazole) nitrate (6), and tetrammine copper(II) dinitramide (7) were synthesized and characterized.