Publication Date:
2014-10-24
Description:
Three trifoliate environmental friendly coordination compounds, [Zn(SCZ) 3 ](NO 3 ) 2 ( 1 ) (SCZ = semicarbazide), [Zn(CHZ) 3 ](NO 3 ) 2 ( 2 ) (CHZ = carbohydrazide), and [Zn(MCZ) 3 ](NO 3 ) 2 · H 2 O ( 3 ) (MCZ = methyl carbazate), were synthesized by the reaction of zinc nitrate with its corresponding ligands. The products were characterized by elemental analysis and FT-IR spectroscopy. Furthermore, compound 1 and 2 were characterized by X-ray single crystal diffraction. The crystal structures of both 1 and 2 belong to the monoclinic P 2 1 / c space group. Remarkably, in all the three compounds, the central zinc cations are six-coordinated with three oxygen atoms of carbonyl groups and three terminal nitrogen atoms of the hydrazine groups from three SCZ / CHZ / MCZ molecules, which can form three five-member (Zn–O–C–N–N) rings and exhibit a distorted octahedron. Thermal stabilities of 1 to 3 were studied by differential scanning calorimetry (DSC) and showed that they are all thermostable. 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 temperature of thermal explosion, entropies of activation (Δ S ≠ ), enthalpies of activation (Δ H ≠ ), and free energies of activation (Δ G ≠ ) were measured and calculated. Sensitivity tests revealed that 1 – 3 are insensitive to mechanical stimuli. The studies of all these three zinc compounds showed that they have potential applications as heat-stable insensitive energetic materials, especially the semicarbazide coordination compound 1 , which has higher crystal density.
Print ISSN:
0044-2313
Electronic ISSN:
1521-3749
Topics:
Chemistry and Pharmacology
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