High-pressure studies on azido-tetrazole chain–ring conversion in crystalline 2-azido-4,6-dichloro-1,3,5-triazine

摘要: First-principle calculations have allowed us to gain insight into the high-pressure effect on azide-tetrazole chain–ring conversion of crystalline 2-azido-4,6-dichloro-1,3,5-triazine in range 0–90 GPa. The local density approximation with Ceperley-Alder exchange–correlation potential parameterized by Perdew and Zunger has been adopted. With increase pressure, unit cell lattice parameters (a, b, c), molecular geometries (bond lengths, interatomic distance, bond angles), atom charges, populations, band gap, states change gradually regularly except at 13, 47, 59 GPa due structural transformation. azido angle reaches maximum 12 GPa then bends 170.76° 13 GPa, but group is approximately linear. From 47 GPa, loses linearity evidently. When pressure boosted 59 GPa, cyclizes completely a five-membered tetrazole ring built, that is, occurs. This structure keeps unchanged under higher pressures till 90 GPa. volumes densities vary stably, no obvious discontinuity happens owing transformation, while small appears total energy 59 GPa. calculated thermodynamic functions suggest may be facile progress according fundamentals chemical thermodynamics.