Preparation, Crystal Structure, and Thermal Analysis of Carbohydrazide Trinitrophloroglucinolate

A new compound (CHZ)(HTNPG)·0.5H₂O was synthesized by mixing carbohydrazide(CHZ) and trinilrophloroglucinol(TNPG) and characterized by elemental analysis and Fourier transform infrared (FTIR) spectrum. Its crystal structure was determined by single crystal X-ray diffraction analysis. The crystal belongs to triclinic system, P{A figure is presented} space group, with a=0.45578(9) nm, b=1.0142(2) nm, c=1.3041(3) nm, α=86.53(3)°, β=99.56(3)°, γ=81.94(3)°, V= 0.5958(2) nm³, Z=2, D_c=2.008 g/cm³, R₁,=0.0476, and wR₂=0.1139. The compound is a di-substituted salt of TNPG, which consists of a cation (CHZ)²⁺ and an anion (HTNPG)²⁺. The thermal analysis of the compound was studied by means of differential scanning calorimetry(DSC) and thermogravimetry-derivative thermogravimetry(TG-DTG). Under nitrogen atmosphere at a heating rate of 10 °C/min, the thermal decomposition of the compound contained one endothermic process of dehydrating stage and two intense exothermic decomposition processes in a temperature range of 140-232 °C on the DSC trace. The decomposition products of the title compound are nearly gaseous products. The existing complicated hydrogen bond networks and electrostatic attraction between (CHZ)²⁺ and (HTNPG)^2- enhance the thermal stability of the title compound.