Synthesis, characterization and properties of tri-substitute potassium salt of trinitrophloroglucinol

The title complex [K₃(TNPG)·(H₂O) ₂]_n was synthesized by the reaction of the aqueous solutions of trinitrophloroglucinol (TNPG) with KHCO₃. The complex was characterized by elemental analysis and FTIR spectroscopy, and its single crystal structure was determined by X-ray diffraction analysis. The structural analysis demonstrates that two different coordination modes of K cations [K(1) and K(2)] are around TNPG^3- anions in complex [K₃(TNPG) ·(H₂O)₂]_n, where the coordination numbers are eight. All K atoms coordinate with O atoms of phenolic hydroxyl group and nitro-group simultaneously. The thermolysis of the [K ₃(TNPG)·(H₂O)₂]_n has been investigated by using differential scanning calorimetry (DSC) and thermogravimetry-derivative thermogravimetry (TG-DTG) at a heating rate of 10°C/min. The thermal decomposition processes of the title complex were comprised of one endothermic dehydration stage and one exothermic decomposition stage in 270-320°C, and the final decomposition residue contained KNC. Impact and friction sensitivity results of the complex revealed its sensitive nature towards mechanical stimuli. The experiments verified that the complex has some characteristics of explosive.