Synthesis,Crystal Structure and Thermal Behavior of GZTO·H2O

Guanidimium‐4,4‐azo‐1‐hydro‐1,2,4‐triazol‐5‐one (GZTO·H₂O) was synthesized from 4‐amino‐1,2,4‐triazol‐5‐one as a starting material by two‐step including oxidation coupling using acid KMnO₄ and reaction with (NH₂)₂C?NH·HNO₃ (GN) in KOH solution. The single crystal of the title compound was obtained by slow evaporation method at room temperature, and its structure was firstly determined with X‐ray single‐crystal diffractometer. It is a orthorhombic crystal, space group Pbca with cell dimensions of a=1.0459(2) nm, b=1.3584(3) nm, c=1.6103(3) nm, α=90.00(10)°, β=90.00(11)°, γ=90.00(11)°, V=2.2878(8) nm³, Z=8, D_c=1.587 g·cm^?3, F(000)=1136, µ=0.132 mm^?1, R₁=0.0455, wR₂=0.1397. The thermal behavior of GZTO·H₂O was studied under a non‐isothermal condition by DSC‐TGA method, and its thermal decomposition process can be divided into three stages, and the first stage is an intense exothermic decomposition process. The second stage and the third stage are slow exothermic decomposition processes. The critical temperature of thermal explosion is 237.74°C.