Precise Equilibrium Structure of Benzene
Precise Equilibrium Structure of Benzene
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苯的精确平衡结构
DOI：
10.1021/jacs.3c03109
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发表时间：
2023
影响因子：
15
通讯作者：
McMahon, Robert J.
中科院分区：
文献类型：
--
作者：
Esselman, Brian J.;Zdanovskaia, Maria A.;Owen, Andrew N.;Stanton, John F.;Woods, R. Claude;McMahon, Robert J.
气相结构测定的最新进展提供了CCSD（T）/cc-pCVTZ校正的半实验（reSE）平衡结构与其相应的平衡结构（re）的最佳理论估计（BTE）之间的出色一致性，该平衡结构（re）基于对CCSD（T）/cc-pCVTZ几何结构的校正。芳香杂环嘧啶和哒嗪。在这里，相同的分析扩展到基本的芳香分子苯，使用已公布的实验光谱数据，共11个可用的同位素。结合所有这些同位素的转动常数和CCSD（T）校正，以解决振动-转动相互作用和电子质量分布的影响，结果在一个高度精确和准确的SE结构。CCSD（T）/cc-pCV 5 Z优化的几何结构已被进一步校正，以解决有限基组，未处理的电子相关，相对论效应和Born-Oppenheimer近似的故障。该分析实现了苯的结构参数（BTE）和reSE之间的高度令人满意的水平（0.0001 μ m）的出色一致性，该一致性超过了我们最近发表的上述氮取代苯类似物的结构。苯的D_（6 h）几何构型已达到前所未有的精确度：RC-C= 1.3913（1）<$，RC-H = 1.0809（1）<$。在这项工作中提出的理论和实验之间的相互协议验证了两者，基本上解决了文献中可用的thereSE和theoreticalrestructures之间的所有差异。
Recent advances in gas-phase structure determination afford outstanding agreement between the CCSD(T)/cc-pCVTZ-corrected semi-experimental (reSE) equilibrium structures and their corresponding best theoretical estimates (BTEs) of the equilibrium structures (re) based upon corrections to the CCSD(T)/cc-pCV5Z geometries for the aromatic heterocycles pyrimidine and pyridazine. Herein, that same analysis is extended to the fundamental aromatic molecule benzene, using published experimental spectroscopic data for a total of 11 available isotopologues. The incorporation of rotational constants from all of these isotopologues and CCSD(T) corrections to address the impacts of both the vibration-rotation interaction and electron-mass distribution results in a highly precise and accuratereSEstructure. The CCSD(T)/cc-pCV5Z optimized geometry has been further corrected to address a finite basis set, untreated electron correlation, relativistic effects, and a breakdown of the Born–Oppenheimer approximation. This analysis achieves outstanding agreement between there(BTE) andreSEstructural parameters of benzene to a highly satisfying level (0.0001 Å), an agreement that surpasses our recently published structures of the aforementioned nitrogen-substituted benzene analogues. TheD6hgeometry of benzene is now known to an unprecedented precision:RC–C= 1.3913 (1) Å andRC–H= 1.0809 (1) Å. The mutual agreement between theory and experiment presented in this work validates both, substantially resolving all discrepancies between thereSEand theoreticalrestructures available in the literature.