Synthesis, Properties And Applications Of Energetic Complexes Among Polyamino And Polynitro Substituted Pyridine N-oxide And Pyrazine N-oxide

In recent years, energetic complexes have received great interests and become an important research direction.2,6-diamino-3,5-dinitropyridine-l-oxide (ANPyO),2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) and2,4,6-triamino-3,5-dinitropyridine-l-oxide (TANPyO) are representative compounds of polyamino and polynitro substituted pyridine N-oxide and pyrazine N-oxide. Nitrogen and oxygen atoms bearing lone pair of electrons in the ring make the ligands possible to coordinate with metals. For the purpose of synthesizing novel energetic complexes with high energy, good safety performance and a high value of application, some complexes were obtained by using the three energetic ligands in coordination with different metal ions. The crystal structures of complexes were determined. The thermal stability, particle size, detonation velocity, detonation pressure, sensitivity, compatibility as well as catalytic performance were studied. Furthermore, the feasibility of complexes as laser primary explosives or combustion catalysts was explored, and the prospect as combustion catalysts of double-based propellants was tested. The main research contents and conclusions were summarized as follows:(1) Twenty-five energetic complexes were synthesized using the three ligands with different metals (iron, cobalt, nickel, copper, zinc, lead) with advantages of simple synthesis process, mild reaction conditions, high product yields and good economic benefits. Complexes were characterized by FT-IR spectroscopy, elemental analysis and X-ray diffraction.(2) The crystal structures of nine complexes were got by X-ray single crystal diffraction, and the coordination mode of ligands with metal ions was identified for the first time. The experimental results revealed that as bidentate or tridentate ligands, the ligands were coordinated with metal ions by oxygen atom from N→O group and nitrogen atom from ortho-amine group which lost a hydrogen atom, the resulting complexes had no external anion. This kind of coordination mode was very special.(3) The thermal stability of all complexes was studied by DSC and TG-DTG technologies. Moreover, the kinetic parameters of the main exothermic process were studied by the Kissinger’s and Ozawa-Doyle’s methods. The results showed that all the complexes had good thermal stability, and the final decomposition products were metal oxides.(4) Some promising complexes were selected to study the application performances. Particle size analysis showed that the complexes had micron particle size; detonation performance showed that detonation velocity (>8200m/s) and detonation pressure (>32GPa) of complexes were higher than TATB、HNS and PYX; sensitivity tests revealed that the complexes were less sensitive to impact, friction and shock than RDX、HNS and PYX; compatibility showed that the complexes had good compatibility with RDX and NC, but bad compatibility with HMX and Al; catalytic test showed that the complexes had little catalytic effects on the thermal decomposition of RDX and HMX, but good catalytic performance to the thermal decomposition of AP.(5) Some target complexes with better performances were selected to study the feasibility as laser primary explosives or combustion catalysts. Laser detonation experiments showed that ANPyO complexes were insensitive to laser and not suitable as laser primary explosives. The closed vessel combustion experiments showed that ANPyO complexes had some catalytic effects on the combustion of double-based propellants and triple-based propellants, which could increase the burning rate and decrease the pressure exponent. Target lines experiments showed that some complexes could increase the burning rate of the double-based propellants effectively, and a low pressure exponent zone was obtained, showing that these complexes were good energetic catalysts.