Synthesis,Structures And Physicochemical Properties Of Energetic Coordination Polymers Based On Tetrazolylfurazan

In recent years,it is widely used explosive energetic ligands to construct novel energetic materials by scientists.Its energy level and sensitivity can be controlled by rational assembly of metal ions and energy ligands.This paper aims to synthesize high energy,insensitive and good thermal stability energetic materials and push it to multi-functionality.Wechoosetetrazolylfurazanderives3-nitro-4-?tetrazol-5-yl?furazan?NTZF?,3-amino-4-?tetrazol-5-yl?furazan?ATZF?and5-?3-Amino-1,2,5-oxadiazol-4-yl?-tetrazol-1-ol?AFTO?as energetic ligands,Cu???,Zn???,Co???as mental center synthesissixenergeticcoordinationpolymers{[Cu?OTZF??H₂O?₃]·H₂O}_n?1?,[Cu₃?OTZF?₂?OH?₂?H₂O?₂]_n?2?,{[Zn?OTZF??H₂O?₃]·H₂O}_n?3?,{[Co?OTZF??H₂O?₃]·2H₂O}_n?4?,[Cu₃?ATZF?₄?CH₃O?₂]_n?5?,[Cu?AFTO?₂?H₂O?₂]_n?6?by hydro/solvothermal methods.The structure and physicochemical properties were studied.At the same time,the effect of its combustion catalyst on the AP was also explored.The research contents and results are as follows:?1?Structures of six energetic coordination polymers was analyzed by X-ray single crystal diffraction,X-ray powder diffraction and infrared spectroscopy.The results show that because of the nitro group in the substrate is easily attacked by nucleophiles in aqueous solution,3-nitro-4-?tetrazol-5-yl?furazanbecome3-hydroxyl-4-?tetrazol-5-yl?furazan,causing hydroxyl groups on the ligands to participate in the coordination.Ligands of 1-4adopt bidentate chelate coordination modes and bridging coordination modes to coordinate with metal ions to form one-dimensional chains or two-dimensional layers.5 and 6 use ATZF and AFTO as ligands,the coordination mode of ligands is only bridge coordination modes.The hydrogen bonds and?···?stacking further enhance the stability of the structure of coordination polymers.The nitrogen content and density of six coordination polymers ranged from 27.91-45.52%and 1.853-2.183 g·cm^-3,respectively.?2?The thermal decomposition process of coordination polymers 1-6 were studied by TG-DSC technique.The results show that polymers 1-5 show good thermal stability,and the range of thermal decomposition temperature is 269.8-295.8?.But 6 has a two-step decomposition,temperature range are 240-260?and 270-360?.Based on Kissinger's and Ozawa-Doyle's methods,the non-isothermal kinetics of coordination polymers 1-6were studied.The values of pre-exponential factor A and apparent activation energy E were obtained by calculation,and we also get thermodynamic equations.The rate constant is estimated to measure the speed of coordination reaction of coordination polymers.Using the pre-exponential factor A and the apparent activation energy E,the thermodynamic parameters[apparent activation enthalpy??H^??,apparent activation entropy??S^??and Gibbs free energy??G^??]of six coordination polymers were calculated.?3?The heat of detonation of coordination polymers were calculated by density functional theory?DFT?.We use Gaussian 09 software to calculate totally systematic energies of six polymers and then use?E_det=-[?_fH_m^??products?-?_fH_m^??explosive?]to estimate the heat of detonation of polymers.Then a series of parameters are substituted into Kamlet-Jacobs equations to derive detonation pressure and detonation velocity of polymers.Among them,the detonation performance of 2 and 4 is superior(2:Q=2.269 kcal·g^-1,D=8.159 km·s^-1,P=32.892 GPa.4:Q=2.165 kcal·g^-1,D=8.846 km·s^-1,P=35.311 GPa).Sensitivity tests showed that coordination polymers 1-6 were insensitive?IS>40 J;FS>360 N?.?4?Using DSC technology to test the effect of coordination polymesr on the thermal decomposition behavior of AP.The results show that coordination polymers 1-6 reduce decomposition temperature of AP to varying degrees.Especially 2,4 and 5 are significant improvements.They combined two decomposition peaks of AP into one sharp exothermic peak.2 advances the peak temperature of high decomposition peak from 442.0?to293.6?,aheading 148.8?.4 advances peak temperature of high decomposition peak from 442.0? to 323.5?,118.5?advanced.And 5 advances the peak temperature of the high decomposition peak from 442.0?to 316.5?,advancing 125.5?.