Chelates with π-stacking and hydrogen-bonding interactions as safer and structurally reinforced energetic materials

Three chelating energetic materials (CEM), [Co(SCZ)(2)(H2O)(2)](TNR)(H2O)(2) (1), [Ni(SCZ)(2)(H2O)(2)](TNR) (H2O)(2) (2) and [Zn(SCZ)(2)(H2O)(2)](TNR)(H2O)(2) (3, SCZ = semicarbazide, H2TNR = styphnic acid), were synthesized and characterized by elemental analysis, FTIR spectroscopy and single-crystal X-ray diffraction analysis. Single-crystal X-ray diffraction analysis revealed that 1 mainly exhibits swathe construction, whereas 2 and 3 manifest grating structure. Thermal decomposition behaviors of 1-3 were studied by differential scanning calorimetry (DSC). The critical temperature of thermal explosion, the entropy of activation (Delta S-not equal), the enthalpy of activation (Delta H-not equal), and the free energy of activation (Delta G(not equal)) were also calculated. Sensitivity tests revealed that 1-3 are insensitive to mechanical stimuli, and that the grating structure (2 and 3) shows better shock resistance and flame retardant property than the swathe construction (1) at the molecular level. (C) 2017 Elsevier B.V. All rights reserved.