A comparative theoretical investigation into the change in strength of the trigger-bond upon formation of the Na+, Mg2+ and HF complexes involving the nitro group of RNO2 (R?=? –CH3, –NH2, –OCH3) or the C?=?C bond of (E)-O2N–CH?=?CH–NO2 was carried out using the B3LYP and MP2(full) methods with the 6-311++G**, 6-311++G(2df,2p) and aug-cc-pVTZ basis sets. Except for the Mg2+?π system with (E)-O2N–CH?=?CH–NO2 (i.e., C2H2N2O4?Mg2+), the strength of the trigger-bond X–NO2 (X?=?C, N or O) was enhanced upon complex formation. Furthermore, the increment of bond dissociation energy of the X–NO2 bond in the Na+ complex was far greater than that in the corresponding HF system. Thus, the explosive sensitivity in the former might be lower than that in the latter. For C2H2N2O4?Mg2+, the explosive sensitivity might also be reduced. Therefore, it is possible that introducing cations into the structure of explosives might be more efficacious at reducing explosive sensitivity than the formation of an intermolecular hydrogen-bonded complex. AIM, NBO and electron density shifts analyses showed that the electron density shifted toward the X–NO2 bond upon complex formation, leading to a strengthened X–NO2 bond and possibly reduced explosive sensitivity.
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Introducing cations into explosives is more efficacious at reducing sensitivity than H-bond formation 相似文献
Utilizing first-principles calculations, we studied the electronic and optical properties of C24, C12X6Y6, and X12Y12 fullerenes (X?=?B, Al; Y?=?N, P). These fullerenes are energetically stable, as demonstrated by their negative cohesive energies. The energy gap of C24 may be tuned by doping, and the B12N12 fullerene was found to have the largest energy gap. All of the fullerenes had finite optical gaps, suggesting that they are optical semiconductors, and they strongly absorb UV radiation, so they could be used in UV light protection devices. They could also be used in solar cells and LEDs due to their low reflectivities.
