Preparation,Structure And Thermal Decomposition Mechanism Of Cu/Pb-tetrazoly Energetic Complexes

In this thesis,seven energetic complexes[Cu₂（DNS）（Tetra）（H₂O）]_n（1）,[Cu（DOBT）（H₂O）₂]_n（2）,[Cu₂（DOBT）₂]_n·n[（CH₃）₄N]（3）,[Pb₃（DOBT）₃]_n·2（H₂O）_n（4）,[Cu（DNS）₂]_n·2（C₂H₈N）_n（5）,[Pb（DNS）]_n（6）and[Zn₅（Tetra）₉]_n（7）were synthesized by using 1H-tetrazole（Tetra）,3,5-dinitrosalicylic acid（DNS）and 1H,1’H-[5,5’-bitetrazole]-1,1’-diol（DHBT）as ligands.The structures of complexes 1-7 were characterized by X-ray single crystal diffraction,X-ray powder diffraction,elemental analyses and FT-IR spectra.The physicochemical properties and the mechanism of thermal decomposition of complexes 1-6 were well investigated.The main contents and conclusions are as follows:1.Using Tetra and DNS as biligands and Cu（II）,the complex 1 with 3D channel structure was synthesized,and the complex 5 was also obtained with a density(1.718 g?cm^-3)lower than 1(2.361 g?cm^-3).Based on DHBT and Cu（II）,complexes 2 and 3 with different structures were synthesized through rational selection of solvents.Complex 2 was synthesized in DMAc/H₂O mixed solvents.Cu（II）is six-coordinated with ligands forming a one-dimensional chain like structure.1D chains are further packed into 3D supramolecular network via hydrogen bonding interactions.Complex 3 was synthesized in DMAc/MeOH mixed solvents.Copper ions adopt four-and five-coordination with ligands to form 3D porous framework.Pb（II）ions adopt four-and six-coordination with DHBT ligands to form a 2D porous structure 4.A 1D complex 6 was synthesized based on DNS and Pb（II）which adopt four-coordination.1H-tetrazole reacts with Zn（II）forming a 3D porous structure.2.The thermal behaviors of complex 1-6 were investigated by TGA and DSC.The results indicate that the six complexes have good thermal stability.There are two complexes（1 and 6）show thermal decomposition temperature higher than 300°C.Through the TG-QMS tests,the decomposition products of complex 1-3 and 5 were analyzed.DSC curves measured at four different heating rates were used to calculate the self-accelerating decomposition temperatures(T_SADT)and the critical temperatures（T_b）of 1-6.The non-isothermal kinetic parameters of 1-6were calculated by the Kissinger’s and Ozawa-Doyle’s methods.3.The constant-volume heats of combustion（Q_v）of the complexes 1-6 were measured by the oxygen bomb calorimeter and the standard enthalpy of combustion（Δ_cH^θ）and the standard enthalpy of formation（Δ_f H^θ）were calculated from Q_v.The results show that the complexes 1,3,6 have high enthalpy of formation,respectively 303.54 kJ·mol^-1,1308.79 kJ·mol^-1,4791.81 kJ·mol^-1,983.33 kJ·mol^-1.4.EXPLO5 software was used to estimate detonation performance of 1-3 and 5 and predict explosion products.The results show that although the heat of detonation and detonation temperature of 3 are relatively high,the detonation velocity and detonation pressure are both lower than 2.The heat of detonation,detonation velocity and detonation pressure of 1 are all higher than 5.The impact sensitivity（IS）and friction sensitivity（FS）of the complexes 1-6were measured by using BAM fall hammer and BAM friction apparatus.The results indicate that 2 is more sensitive than 3.1,5 and 6 are insensitive to external stimuli.