Synthesis and Investigation of Energetic Boron Compounds for Pyrotechnics

The energetic boron esters tris(1-ethyl-5-aminotetrazolyl) borate, tris(2-ethyl-5-aminotetrazolyl) borate, tris(1-ethyltetrazolyl) borate, tris(2-ethyltetrazolyl) borate, and tris(2-(3-nitro-1,2,4-tri-azolyl) ethyl) borate were synthesized and analyzed by NMR and IR spectroscopy, elemental analysis, and mass spectrometry. Two tetracoordinate borates potassium tetrakis(3-nitro-1,2,4-triazolyl)borate and potassium bis(4,4',5,5'-tetranitro-2,2'-bisimidazolyl)borate were synthesized and fully characterized as well. Moreover, the energetic and thermal properties of the energetic boron esters and tetracoordinate borates were determined. The B-11 NMR chemical shifts of potassium tetrakis(3-nitro-1,2,4-triazolyl)borate and potassium bis(4,4',5,5'-tetranitro-2,2'-bisimidazolyl) borate were calculated and compared to the experimental values. Tris(1-ethyl-5-aminotetrazolyl)borate was tested as colorant in pyrotechnic formulations with respect to the combustion behavior and color properties as well as the energetic and thermal properties.