Innovative Concept of Designing Primary Explosives by IntroducingPolymers: Preparation and Investigation of {[Ca(CHZ)2](ClO4)2}n (CHZ = carbohydrazide)

Abstract

A novel alkaline‐earth metal perchlorate coordination polymer {[Ca(CHZ)2](ClO4)2}n (1, CHZ = carbohydrazide) was synthesized and characterized. The X‐ray single‐crystal diffraction results illustrate that the structure of the complex belongs to a tetragonal system, space group I‐42m. Every Ca2+ ion is octa‐coordinated with four CHZ groups. The CHZ group forms a tridentate coordination mode with different Ca2+ ions, leading to a coordination polymer structure. Therefore, the molecule is extended to a super 1D infinite polymer, and the configuration of the Ca2+ ion is a distorted dodecahedron. The DSC results show only one exothermal decomposition process with a peak temperature of 242.2 °C. The TG‐DTG curves demonstrate a 58 % mass loss from 210–290 °C and that finally 18 % of the polymer remains. Experimental data show that the combustion heat is –6.41 MJ kg–1 and the enthalpy of formation is –610.9 kJ mol–1. Non‐isothermal kinetic and thermodynamic parameters are obtained from Kissinger's method as well as Ozawa's method. The critical temperature of thermal explosion, ΔS≠, ΔH≠, and ΔG≠ are calculated as 234.7 °C, 134.1 J K–1 mol–1, 213.8 kJ mol–1, and 147.0 kJ mol–1, respectively. Additionally, the sensitivities towards impact and friction are assessed to be 0.5 J and 28 N from the relevant standard methods.