The origin of the cation/π interaction: The significant importance of the induction in Li+ and Na+ complexes
The origin of the cation/π interaction: The significant importance of the induction in Li+ and Na+ complexes
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DOI：
10.1021/jp003287v
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发表时间：
2001-02-01
影响因子：
2.9
通讯作者：
Mikami, M
中科院分区：
文献类型：
--
作者：
Tsuzuki, S;Yoshida, M;Mikami, M
在MP2/6- 311 G ** 水平上计算了阳离子/π络合物（阳离子= Li+、Na+和K+，π体系=苯、甲苯、甲苯和叔丁基苯）的相互作用能.用分布多极子和分布极化率模型计算了静电能和感应能。感应和静电相互作用是吸引力的主要来源。Li ~+/π配合物的E-ind值比E-es大2.5-2.8倍。Na+/pi复合物的E-ind值比E-es大40-80%。感应能量与R-4近似成正比。苯的薄的结构使阳离子与苯的碳原子有短的接触，这是大的E-ind所必需的。Li+/环己烷络合物的E-ind值显著小于Li+/苯络合物的E-ind值。Li+/环己烷配合物具有较大的分子间分离，因此具有较小的E-ind，而Li+/环己烷配合物的E-ind较小，E-es可忽略不计，这是导致Li+/环己烷配合物结合能较小的原因。叔丁基苯配合物具有比苯配合物更大的结合能。叔丁基苯络合物中较大的E-ind是其结合能较大的原因。
The interaction energies of the cation/pi complexes (cation = Li+, Na+, and K+, pi system = benzene, toluene, ethylbenzene, and tert-butylbenzene) were calculated at the MP2/6-311G** level. The electrostatic (E-es) and induction (E-ind) energies were calculated with distributed multipoles and distributed polarizabilities model. Induction and electrostatic interactions are the major source of the attraction. The E-ind values of the Li+/pi complexes are 2.5-2.8 times larger than the E-es. The E-ind values of the Na+/pi complexes are 40-80% larger than the E-es. The induction energy is approximately proportional to R-4. The thin structure of the benzene, which enables the cation to have the short contact with carbon atoms of benzene, is essential for the large E-ind. More polarizable cyclohexane is not a better cation binder than benzene. The E-ind value of the Li+/ cyclohexane complex is considerably smaller than that of the Li+/benzene complex. The Li+/cyclohexane complex has larger intermolecular separation, and therefore has the smaller E-ind. The small E-ind and negligible E-es of the Li+/cyclohexane complex are the causes of the smaller binding energy of the Li+/cyclohexane complex. The tert-butylbenzene complexes have larger binding energies than the benzene complexes. The larger E-ind in the tert-butylbenzene complexes are the cause of the larger binding energy.