Molecular structures of mononitrophenols and their thermal decomposition tautomers
Molecular structures of mononitrophenols and their thermal decomposition tautomers
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DOI：
10.1016/s0166-1280(97)00289-3
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发表时间：
1998-03-23
期刊：
影响因子：
--
通讯作者：
Tzeng, SC
中科院分区：
文献类型：
--
作者：
Chen, PC;Lo, W;Tzeng, SC
采用HF/6-31G*基集，用从头算方法计算了2-硝基、3-硝基和4-硝基苯酚及其内部旋转异构体的分子结构。硝基的位置影响了几何形状。在2-硝基苯酚中观察到羟基对硝基的扰动，其分子结构与其他两种异构体不同。其中，2-硝基苯酚是最稳定的一种。对3-硝基和4-硝基苯酚的硝基或羟基进行内旋试验表明，内旋后苯环没有发生明显变形；然而，2-硝基苯酚的内部旋转异构体与原来的结构不同。由于热或冲击诱发的爆炸物的产物，选择了四种2-硝基苯酚的互变异构体来评估它们的几何形状和能量。计算表明，这些产物在热力学上是不利的。对比2-硝基苯酚和2-硝基苯胺及其互变异构体的计算能发现，2-硝基苯酚比2-硝基苯胺更容易发生热分解。本研究结果为芳香族硝基化合物的敏感性提供了有价值的信息。(C) 1998爱思唯尔科学有限公司
The molecular structures of 2-nitro, 3-nitro, and 4-nitrophenol and their internal rotational isomers were calculated by an ab initio method using an HF/6-31G* basis set. The nitro groups' position influenced the geometries. The perturbation of the hydroxyl group on the nitro group was observed in 2-nitrophenol which has a molecular structure distinct from that of the other two isomers. Among them, 2-nitrophenol is the most stable one. Tests of internal rotation of either the nitro or hydroxyl group of 3-nitro and 4-nitrophenol indicate that no significant deformations of the phenyl ring occurred after internal rotation; however, the internal rotational isomers of 2-nitrophenol differed from their original structure. As products of explosives induced by thermal or shock are of interest, four tautomers of 2-nitrophenol were selected to assess their geometries and energies. The calculations revealed that those products are thermodynamically unfavorable. Comparing calculated energies of 2-nitrophenol and 2-nitroaniline and their tautomers reveals that 2-nitrophenol more easily undergoes thermal decomposition than 2-nitroaniline. Results in this study provide valuable information regarding the sensitivity of aromatic nitrocompounds. (C) 1998 Elsevier Science B.V.