Studies on three-dimensional coordination polymer [Cd 2(N 2H 4) 2(N 3) 4] n: Crystal structure, thermal decomposition mechanism and explosive properties

Abstract

A 3D coordination polymer of cadmium(II) hydrazine azide, [Cd 2(N 2H 4) 2(N 3) 4] n , was synthesized and characterized by elemental analysis and Fourier transform infrared (FT-IR) spectrum. Its crystal structure was determined by single crystal X-ray diffraction analysis. The crystal belongs to monoclinic, P2 1/ c space group, a = 12.555(2) Å, b = 11.724(2) Å, c = 7.842(1) Å, β = 94.56(2)° and Z = 4. The crystal contains two crystallographically independent sets of distorted octahedral Cd(II) atoms and dimeric units of Cd 2N 2, Cd 2(NNN) 2, Cd 2(NN) 2 through double μ-1, 1 azide bridges, μ-1, 3 azide bridges and bidentate bridging hydrazine ligands, respectively, and thus generating a 3D network structure. The thermal decomposition mechanism of the complex was studied by using differential scanning calorimetry (DSC), thermogravimetry–derivative thermogravimetry (TG–DTG) and FT-IR techniques. Under nitrogen atmosphere with a heating rate of 10 °C/min, the thermal decomposition of the complex contained two intense exothermic decomposition processes in the range of 150–304 °C in the DSC curve, and the final decomposed residue at 500 °C was Cd. Sensitivity tests revealed that the title complex is very insensitive to external stimuli.