Substituent effects in parallel-displaced π-π interactions
Substituent effects in parallel-displaced π-π interactions
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DOI：
10.1039/b718742d
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发表时间：
2008-01-01
影响因子：
3.3
通讯作者：
Sherrill, C. David
中科院分区：
文献类型：
--
作者：
Arnstein, Stephen A.;Sherrill, C. David
高质量的量子力学方法用于研究取代基如何调节平行位移几何结构中单取代苯二聚体之间的 pi-pi 相互作用。本研究的重点是取代基在整个势能曲线上的影响。通过使用对称适应微扰理论，根据相互作用的基本组成部分（静电、交换排斥、色散和感应）来检查取代基效应。具有截断的 aug-cc-pVDZ' 基础的二阶 Moller-Plesset 微扰理论 (MP2) 和具有 aug-cc-pVTZ 基础的自旋分量尺度 MP2 (SCS-MP2) 都被发现可以精确模拟 aug-cc-pVTZ 基础上具有微扰三元组 [CCSD(T)] 的耦合簇的估计。取代基可以对芳环 pi 云的电子结构产生显着影响，导致 pi-pi 相互作用发生显着变化。此外，一个环上的取代基与另一环的π云之间也可能存在显着的直接相互作用。
High-quality quantum-mechanical methods are used to examine how substituents tune pi-pi interactions between monosubstituted benzene dimers in parallel-displaced geometries. The present study focuses on the effect of the substituent across entire potential energy curves. Substituent effects are examined in terms of the fundamental components of the interaction (electrostatics, exchange-repulsion, dispersion and induction) through the use of symmetry-adapted perturbation theory. Both second-order Moller-Plesset perturbation theory (MP2) with a truncated aug-cc-pVDZ' basis and spin-component-scaled MP2 (SCS-MP2) with the aug-cc-pVTZ basis are found to mimic closely estimates of coupled-cluster with perturbative triples [CCSD(T)] in an aug-cc-pVTZ basis. Substituents can have a significant effect on the electronic structure of the pi cloud of an aromatic ring, leading to marked changes in the pi-pi interaction. Moreover, there can also be significant direct interactions between a substituent on one ring and the pi-cloud of the other ring.