Preparation, crystal structure, thermal decomposition, quantum chemical calculations on [K(ZTO)⋅H2O]∞ and its ligand ZTO

A novel potassium complex has been synthesized and characterized under the non-isothermal conditions by DSC and TG-DTG method. The 4,4-azo-1,2,4-triazol-5-one (ZTO) has the molecular formula C4H4N8O2. The thermodynamic parameters, HOMO–LUMO energy gap, total energy and electrostatic potential (MEP) of ZTO are conducted by density functional theory DFT/B3LYP calculation method with 6-311G basis set. In the coordination polymer, with the ligand anion (ZTO−) as space linkers, two types of potassium atoms centers are joined together to form three-dimensional frameworks. The enthalpy, apparent activation energy and pre-exponential factor of the second exothermic decomposition reaction are 85.43 kJ mol−1, 414.4 kJ mol−1and 1037.92 s−1, respectively. The critical temperature of thermal explosion (Tb) for [K(ZTO)⋅H2O]∞ is 275.08 °C. [K(ZTO)⋅H2O]∞ CCDC: 902339.

► The new metal–ligand was synthesized and its thermal decomposition was described.
► Structure of metal–ligand was confirmed by X-ray analysis.
► The thermodynamic parameters, HOMO–LUMO energy gap and ESP surface of the ligand (ZTO) was acquired through DFT calculation.