N-functionalized nitroxy/azido fused-ring azoles as high-performance energetic materials†
A series of fused ring-based nitrate esters/azides and a coupled-ring-based nitrate ester were prepared using a simple and efficient nitrogen-functionalization approach. All new energetic compounds were fully characterized. Structures of four (1–4) were further confirmed by single crystal X-ray diffraction. These nitrate esters have good thermal stabilities and high densities. Energetic performance was evaluated by using EXPLO5 v6.01 based on measured densities and calculated heats of formation (Gaussian 03 (Revision D. 01)). The results show that some of the representative fused ring-based nitrate esters exhibit good detonation properties, for example, 1 (vD, 8674 m s−1; P, 33.1 Gpa) and 2 (vD, 8669 m s−1; P, 33.4 Gpa), that approach those of current high explosive benchmarks, such as 1,3,5-trinitroperhydro-1,3,5-triazine (RDX). Sensitivity data based on impact and friction tests show these compounds have better stabilities than the traditional nitrate ester explosive, pentaerythritol tetranitrate (PETN).