The molecular geometry,electronic structure,thermochemistry and infrared spectra of [Mg(CHZ)3](ClO4)2 and [Mg(CHZ)3](NO3)2 were comparatively studied using the Heyd-Scuseria-Ernzerhof(HSE) screened hybrid density functional with 6-31G** basis set.The experimental results show that the complexes have six-coordinated octahedron feature,and the metal-ligand interactions are predominantly ionic in nature.The calculated heats of formation predict that [Mg(CHZ)3](NO3)2 is more stable than [Mg(CHZ)3](ClO4)2.Detailed NBO analyses indicate that the ligand-anion interaction plays an important role in the stability for these two energetic complexes.Moreover,the stretching vibration frequencies of N-H bonds shift to lower wave number compared to the free CHZ ligand,which are caused by the delocalizations from N-H bond orbital to lone-pair electron antibond orbital of magnesium.
The geometric structure, mechanism of detonation initiation and stability of transition metal carbohydrazide (CHZ) nitrates are investigated via density functional theory. The obtained results show that the Heyd-Scuseria-Ernzerhof (HSE) functional yields the most accurate geometry. The initiating reaction of detonation in [Mn(CHZ)3](NO3)2 and [Zn(CHZ)3](NO3)2 is the formation of NO3 radicals. The calculated heat of formation and energy gap predict that the Mn and Zn complexes, which have the half-filled (3d5) and full-filled (3d10) electron configurations for the transition metal ions, respectively are more stable than the Co, Ni and Cu complexes. This indicates that the electron configuration of transition metal ion plays an important role in the stabilities of these energetic complexes.
An energetic salt, sodium nitroformate (NaNF), was synthesized and characterized by elemental analysis, IR and UV spectra, and its crystal structure was first determined by single crystal X-ray diffraction. The structure exhibits two types of π-π stacking interactions between the nitroformate anions, i e, the parallel-displaced and T-shaped confgurafions. Furthermore, the thermal decomposition mechanism was investigated by DSC, TG-DTG and FTIR techniques. The kinetic parameters of the thermal decomposition were also calculated by using Kissinger's and Ozawa-Doyle's methods. The results show that NaNF has a good thermal stability, which is attributed to the π-π stacking interactions.