On the HALA effect in the NMR carbon shielding constants of the compounds containing heavy p‐elements
On the HALA effect in the NMR carbon shielding constants of the compounds containing heavy p‐elements
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DOI：
10.1002/qua.25196
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发表时间：
2016-10
影响因子：
2.2
通讯作者：
Yury Yu. Rusakov;I. L. Rusakova;L. Krivdin
中科院分区：
文献类型：
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作者：
Yury Yu. Rusakov;I. L. Rusakova;L. Krivdin
计算研究了重原子（HA）对模型乙烷、乙烯和乙炔系列CβH3 <$CαH2 <$XHn、CβH2 <$CαH <$XHn、CβH <$Cα <$XHn（n= 0、1、2或3，取决于X）NMR各向同性碳屏蔽常数的影响，其中X涵盖了多达60个化合物中3-6个周期的13-17族p-元素。所研究的化合物为α-和β-碳提供了不同的成键情况，其特征在于Cβ <$Cα和Cα <$X键的s-特征连续增加，这是影响HA的自旋轨道部分对轻原子效应（SO-HALA）的因素之一。第16、15、14和13族分别建立了“硫族元素依赖性”、“磷族元素依赖性”、“四元依赖性”和“三元依赖性”。13 C NMR化学位移的一个众所周知的“正常卤素依赖性”，在包含第17族元素的化合物中建立得更早，也在研究的所有三个系列中显示出来。还研究了自旋轨道效应大小与HA X上孤电子对（LEP）数量的依赖关系。对三种有代表性的碲化物的~（13）C NMR化学位移进行了理论计算和实验比较。在这一系列的HALA效应已被证明是强烈依赖于碲LEPs的数量。
The heavy atom (HA) effect on the NMR isotropic carbon shielding constants is computationally investigated in the series of model ethanes, ethylenes, and acetylenes, CβH3CαH2XHn, CβH2CαHXHn,CβHCαXHn(n= 0, 1, 2, or 3 depending on X), where X covers p‐elements in the 13–17 groups of the 3–6 periods in as many as 60 compounds. Compounds under study provide diverse bonding situations for the α‐ and β‐carbons, which are characterized by the consecutive increase of the s‐character of the CβCαand CαX bonds, being one of the factors influencing spin‐orbit part of the HA on light atom effect (SO‐HALA). The “chalcogen dependence,” “pnictogen dependence,” “tetrel dependence,” and “triel dependence” are established for the 16th, 15th, 14th, and 13th groups, respectively. A well‐known “normal halogen dependence” for the13C NMR chemical shifts, established much earlier for the compounds containing 17th group elements, also revealed itself in all three series under investigation. The dependence of the spin‐orbit effects size depending on the number of the lone electron pairs (LEPs) on HA X has also been investigated. The comparison of theoretical13C NMR chemical shifts with experiment is performed for three representative tellurides. The HALA effect in this series has been shown to be strongly dependent on the number of tellurium LEPs.