Preparation, crystal structures and thermal decomposition of three energetic manganese compounds and a salt based on imidazole and picrate

The multi-ligand coordination compound of [Mn(H2O)(6)](PA)(2)center dot 2H(2)O (1), [Mn(IMI)(2)(H2O)(4)](PA)(2) (2) and [Mn(IM)(6)](PA)(2)center dot H2O (3), and a salt of (IMI)(PA)center dot H2O (4) were synthesized by using imidazole (IMI) and picrate (PA). Furthermore, they were characterized by elemental analysis and FT-IR spectrum. The crystal structures were determined by X-ray single crystal diffraction. The obtained results show the crystals of 1 and 4 belong to orthorhombic, Pccn and Pna2(1) space groups, and the crystals of 2 and 3 belong to monoclinic, P2(1)/c space groups. The metal Mn(II) cations are six-coordinated and exhibit distorted-octahedral configuration. Under nitrogen atmosphere with a heating rate of 10 K min(-1), the thermal decompositions contain two main exothermic stages in the DSC curves corresponding to TG-DTG curves. The non-isothermal kinetics parameters were calculated by the Kissinger's method and Ozawa's method, respectively. The energies of combustion, enthalpies of formation, critical temperatures of thermal explosion, entropies of activation (Delta S-not equal), enthalpies of activation (Delta H-not equal), and free energies of activation (Delta G(not equal)) were measured and calculated. In the end, the sensitivity properties were also determined with standard methods. (C) 2013 Elsevier Ltd. All rights reserved.