Synthesis And Properties Of Bis-tetrazole Energetic Complexes Of Transition Metals

Bistetrazole compounds have been utilized as one of the most promising candidate in high energy density materials (HEDM) owing to their higher performance of high energy densities, low sensitivity and the environmental acceptability. As a ligand, 5,5'-azoterazolate(ATZ^2-) and N, N-bis-(1(2)H-tetrazol-5-yl-)ammonium(BTA^2-) possess various coordination chemistry. The introduction of ancillary ligand in Bistetrazole-type energetic complexes was employed in pursuit of the coordination of high energy and stability in energetic complexes. In this dissertation, the crystal structure, thermal stability were determined, the effects on the thermal decomposition behavior of complexes act on the main component of propellant were investigated to support the application of complexes in propellant. The main research contents and conclusions in this dissertation were summarized as follows:(1) 34 transition metal complexes in six series, MATZ·nH₂O, MATZ(phen)_m·nH₂O, MATZ(bpy)_m·nH₂O, MBTA·nH₂O, MBTA(phen)_m·nH₂O and MBTA(bpy)_m·nH₂O(M = Mn , Co , Ni , Cu , Zn , Pb)(ATZ^2-= 5,5'-azoterazolate , BTA^2- = N, N-bis-(1(2)H-tetrazol-5-yl-)ammonium), have been prepared based on the basic ligands ATZ^2- and BTA^2- and the ancillary ligands 1,10-phenanthroline and 2,2'-bipyridyl in water or mixture of water and ethanol. Heats in the synthetic processes were measured by microcalorimetry to evaluate the feasibility of liquid reaction in view of energy. The experimental results revealed that the exothermic reaction benefit the proceeding of the reactions and thus provide a thermodynamic reason for the occurrence of the reactions.(2) The complexes were characterized by IR and single-crystal X-ray diffraction. The experimental results revealed that the basic ligands employed different coordination mode in complexes. Four new coordination type of ATZ^2- were found and BTA^2- also coordinated to metal in a new way.(3) The thermal decomposition behaviors of the complexes have been performed: The water in all complexes loss easily and the dehydration products of mixed complexes have high thermal stability. The introduction of an ancillary ligand phen to the complexes played an important role in the thermal stabilities of the dehydration products in complexes of series 2 and 3 or 5 and 6 for its bigger conjugative effect than bpy, and for the series complexes of 2 and 5 or 3 and 6, The bidentate chelating behavior of BTA^2- enhanced the thermal stability of its dehydration products.(4) The effects on the thermal decomposition behavior of complexes act on the main component of propellant (RDX,HMX,NC/NG and AP) were investigated with DSC technique. The experimental results indicated that the thermal stability of dehydration products of complexes played an important role in the thermal decomposition of the main component of propellant. The decomposition processes of binary mixture composed of complexes and the main component of propellant accorded with the kinetic compensation effect.(5) Complexes Pb(ATZ)(BPY)·3H₂O (3-6) and Pb(BTA)(BPY) (6-6) on the combustion properties of double-based and RDX-CMDB propellants were investigated. It was found that the two complexes possess better catalytic effects for the propellants. The burning rate of the propellant was increased, and a low pressure exponent zone was obtained under the experimental conditions. The experimental results showed that these salts are good energetic catalysts.