Strong orbital interaction in a weak CH-π hydrogen bonding system.
Strong orbital interaction in a weak CH-π hydrogen bonding system.
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DOI：
10.1038/srep22304
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发表时间：
2016-03-01
影响因子：
4.6
通讯作者：
Zhang RQ
中科院分区：
文献类型：
--
作者：
Li J;Zhang RQ
本文首次采用基于不同方法和基集的从头算方法，研究了弱相互作用体系代表苯-甲烷配合物中苯与甲烷的分子间轨道相互作用。我们的结果表明，苯和甲烷之间存在明显的分子间轨道相互作用，包括轨道重叠，包括已占据轨道和未占据轨道。与原子间轨道相互作用类似，轨道的分子间相互作用形成“成键”和“反键”轨道。在已占轨道间的相互作用中，由于反键轨道的占据，配合物的总能量增加。由于苯和甲烷之间存在CH-π氢键，使得分子间相互作用能降低到- 1.51 kcal/mol。我们的发现将轨道相互作用的概念从分子内扩展到分子间，并对苯-甲烷配合物的深度轨道改造给出了可靠的解释。
For the first time, the intermolecular orbital interaction between benzene and methane in the benzene-methane complex, a representative of weak interaction system, has been studied by us using ab initio calculations based on different methods and basis sets. Our results demonstrate obvious intermolecular orbital interaction between benzene and methane involving orbital overlaps including both occupied and unoccupied orbitals. Similar to interatomic orbital interaction, the intermolecular interaction of orbitals forms “bonding” and “antibonding” orbitals. In the interaction between occupied orbitals, the total energy of the complex increases because of the occupation of the antibonding orbital. The existence of the CH-π hydrogen bond between benzene and methane causes a decrease in rest energy level, leading to at least −1.51 kcal/mol intermolecular interaction energy. Our finding extends the concept of orbital interaction from the intramolecular to the intermolecular regime and gives a reliable explanation of the deep orbital reformation in the benzene-methane complex.