Calculations predict a novel desired compound containing eight catenated nitrogen atoms: 1-amino-tetrazolo-[4,5-b]tetrazole

Abstract

A novel 8-N conjoined energetic compound 1-amino-tetrazolo-[4,5-b]tetrazole has been designed and investigated at the DFT-B3LYP/6-311++G** level of theory. The optimized geometry, vibration analysis, including thermochemistry and IR spectrum, NMR data, natural bond orbital and charges, HOMO–LUMO orbitals as well as electrostatic potential were calculated for inspecting the electronic structure properties and interactions of chemical bonds. Properties such as density, enthalpy of formation considering the enthalpy of phase transition and detonation performance have also been predicted. As a result, the detonation velocity and pressure of this compound are 8.90 km s⁻¹ and 33.83 GPa, respectively. The planar double rings (stable) with high-nitrogen structure (energetic), the high positive heat of formation (792.38 kJ mol⁻¹) and the eminent performance, lead 1-amino-tetrazolo-[4,5-b]tetrazole to be a potentially very promising powerful energetic insensitive compound. In addition, the azido-cyclization kinetics of 1-amino-5-azidotetrazole forming the target compound have been investigated. In the gaseous state, the reaction barrier is 30.34 kcal mol⁻¹ and the reaction is endothermic as well as non-spontaneous under general conditions. The rate constants are evaluated over a wide temperature region from 200 to 1000 K using the transition state theory (TST) and the Arrhenius experience formula has been fitted as well. The theoretical researches on extended nitrogen chains could improve the synthesis of new high-nitrogen materials in the foreseeable future.