N-Azidoethyl azoles through N-alkylation under highly harmonized reaction conditions: Synthesis, characterization, and complexation as energetic coordination compounds

Abstract

Organic azides are universally important in many areas of chemistry, particularly in organic synthesis. The availability of these azides often depends on specific transfer reagents and reaction conditions, or only work with certain substrates. Customizable transfer reagents offer a safe and direct pathway to desired compounds, thereby increasing the availability of N-alkyl-azides. In an effort to streamline the synthesis and broaden the scope of N-azidoethyl-containing molecules, three different versatile azidoethyl transfer reagents were synthesized and a uniform reaction protocol with azoles as substrates, including imidazole, pyrazole, 1,2,3-triazole, 1,2,4-triazole, and tetrazole was established. The resulting azidoethyl-azoles were further used as ligands for energetic coordination compounds in an effort to create new lead-free primary explosives. A comprehensive characterization of the transfer reagents, the azidoethyl-containing products, and energetic coordination compounds was conducted using multinuclear nuclear magnetic resonance (NMR), elemental analysis, mass spectrometry, and infrared spectroscopy (IR). Furthermore, their thermal stability and sensitivity toward friction and impact were determined as well as the detonation properties were calculated by using the EXPLO5 code.