σ–Hole activation and structural changes upon perfluorination of aryl halides: direct evidence from gas phase rotational spectroscopy
σ–Hole activation and structural changes upon perfluorination of aryl halides: direct evidence from gas phase rotational spectroscopy
复制标题
芳基卤化物全氟化时的空穴活化和结构变化：来自气相旋转光谱的直接证据
DOI：
10.1039/d1cp03023j
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发表时间：
2021
影响因子：
3.3
通讯作者：
Pate, Brooks H.
中科院分区：
文献类型：
--
作者：
Lv, Dingding;Maris, Assimo;Evangelisti, Luca;Maggio, Andrea;Song, Wentao;Elliott, Ashley A.;Peebles, Sean A.;Neill, Justin L.;Muckle, Matt T.;Pate, Brooks H.
通过使用扩展汤斯-戴利（ETD）模型结合对两种全氟芳基卤（C6 F5 Cl和C6 F5）的自然原子轨道键分析，证明了由于环的全氟化而导致芳基卤原子上的σ-空穴的增强。5溴）及其氢化对应物。的ETD分析，量化的卤素p-轨道的人口，依赖于核四极耦合常数，在这项工作中准确地确定实验从旋转光谱。本文报道了用傅里叶变换微波光谱法研究C_6F_5Cl和C_6F_5Br的转动光谱及其天然丰度的~（13）C、~（37）Cl或~（81）Br取代同位素。实验确定的旋转常数结合在MP2/aug-cc-pVTZ水平的理论数据提供了精确的结构信息，从该环的伸长沿着其对称轴，由于perturbance被证明。
Enhancement of the σ–hole on the halogen atom of aryl halides due to perfluorination of the ring is demonstrated by use of the Extended Townes−Dailey (ETD) model coupled to a Natural Atomic Orbital Bond analysis on two perfluorinated aryl halides (C6F5Cl and C6F5Br) and their hydrogenated counterparts. The ETD analysis, which quantifies the halogen p-orbitals populations, relies on the nuclear quadrupole coupling constants which in this work are accurately determined experimentally from the rotational spectra. The rotational spectra investigated by Fourier-transform microwave spectroscopy performed in supersonic expansion are reported for the parent species of C6F5Cl and C6F5Br and their 13C, 37Cl or 81Br substituted isotopologues observed in natural abundance. The experimentally determined rotational constants combined with theoretical data at the MP2/aug-cc-pVTZ level provide precise structural information from which an elongation of the ring along its symmetry axis due to perfluorination is proved.