College of Chemical Engineering and Environment, North University of China, Taiyuan, China.
J Mol Model. 2012 May;18(5):2105-15. doi: 10.1007/s00894-011-1229-7. Epub 2011 Sep 9.
The explosive sensitivity upon the formation of molecule-cation interaction between the nitro group of 3,4-dinitropyrazole (DNP) and H(+), Li(+), Na(+), Be(2+) or Mg(2+) has been investigated using the B3LYP and MP2(full) methods with the 6-311++G** and 6-311++G(2df,2p) basis sets. The bond dissociation energy (BDE) of the C3-N7 trigger bond has also been discussed for the DNP monomer and the corresponding complex. The interaction between the oxygen atom of nitro group and H(+) in DNP…H(+) is partly covalent in nature. The molecule-cation interaction and bond dissociation energy of the C3-N7 trigger bond follow the order of DNP…Be(2+) > DNP…Mg(2+) > DNP…Li(+) > DNP…Na(+). Except for DNP…H(+), the increment of the trigger bond dissociation energy in comparison with the DNP monomer correlates well with the molecule-cation interaction energy, natural charge of the nitro group, electron density ρ(BCP(C3-N7)), delocalization energy E(2) and NBO charge transfer. The analyses of atoms in molecules (AIM), natural bond orbital (NBO) and electron density shifts have shown that the electron density of the nitro group shifts toward the C3-N7 trigger bond upon the formation of the molecule-cation interaction. Thus, the trigger bond is strengthened and the sensitivity of DNP is reduced.
采用 B3LYP 和 MP2(full)方法，结合 6-311++G**和 6-311++G(2df,2p)基组，研究了 3,4-二硝基吡唑（DNP）的硝基与 H(+)、Li(+)、Na(+)、Be(2+)或 Mg(2+)形成分子-阳离子相互作用时的爆炸感度。还讨论了 DNP 单体和相应配合物中 C3-N7 引发键的键离解能（BDE）。DNP 中硝基与 H(+)之间的氧原子的相互作用具有部分共价性质。C3-N7 引发键的分子-阳离子相互作用和键离解能的顺序为 DNP…Be(2+) > DNP…Mg(2+) > DNP…Li(+) > DNP…Na(+)。除了 DNP…H(+)之外，与 DNP 单体相比，引发键离解能的增量与分子-阳离子相互作用能、硝基的自然电荷、BCP(C3-N7)处的电子密度 ρ、离域能 E(2)和 NBO 电荷转移很好地相关。分子中原子（AIM）、自然键轨道（NBO）和电子密度位移的分析表明，在形成分子-阳离子相互作用时，硝基的电子密度向 C3-N7 引发键转移。因此，引发键得到加强，DNP 的感度降低。
