Origin of attraction, magnitude, and directionality of interactions in benzene complexes with pyridinium cations
Origin of attraction, magnitude, and directionality of interactions in benzene complexes with pyridinium cations
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DOI：
10.1021/ja071372b
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发表时间：
2007-07-11
影响因子：
15
通讯作者：
Yamada, Shinji
中科院分区：
文献类型：
--
作者：
Tsuzuki, Seiji;Mikami, Masuhiro;Yamada, Shinji
用从头算分子轨道法研究了苯与吡啶、吡啶、n -甲基吡啶配合物的几何形状和相互作用能。在基集极限下，复合物的CCSD(T)相互作用能分别为-3.04、-14.77和-9.36 kcal/mol。吡啶和n -甲基吡啶配合物中的相互作用应归类为阳离子/ π相互作用，因为静电和感应相互作用极大地促进了吸引力。另一方面，吡啶配合物中的相互作用是π / π相互作用。在苯-吡啶配合物中，色散相互作用是吸引的主要原因。包括电荷转移相互作用在内的短程相互作用对三种配合物的吸引并不重要。最稳定的吡啶配合物具有t形结构，其中N-H键指向苯，而n -甲基吡啶配合物倾向于滑移平行结构。苯-吡啶配合物具有两种几乎等能的结构（滑移平行和t形）。
Geometries and interaction energies of benzene complexes with pyridine, pyridinium, N-methylpyridinium were studied by ab initio molecular orbital calculations. Estimated CCSD(T) interaction energies of the complexes at the basis set limit were -3.04, -14.77, and -9.36 kcal/mol, respectively. The interactions in the pyridinium and N-methylpyridinium complexes should be categorized into a cation/pi interaction, because the electrostatic and induction interactions greatly contribute to the attraction. On the other hand, the interaction in the pyridine complex is a pi/pi interaction. The dispersion interaction is mainly responsible for the attraction in the benzene-pyridine complex. Short-range interactions including charge-transfer interactions are not important for the attraction in the three complexes. The most stable pyridinium complex has a T-shaped structure, in which the N-H bond points toward the benzene, while the N-methylpyridinium complex prefers a slipped-parallel structure. The benzene-pyridine complex has two nearly isoenergetic (Slipped-parallel and T-shaped) structures.