Nature of hydrogen-bond-enhanced halogen bonding viewed through electron density changes
Nature of hydrogen-bond-enhanced halogen bonding viewed through electron density changes
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通过电子密度变化观察氢键增强卤键的性质
DOI：
10.1039/d2cp02845j
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发表时间：
2022
影响因子：
3.3
通讯作者：
Sakai Takanori
中科院分区：
文献类型：
--
作者：
Torii Hajime;Kimura Akari;Sakai Takanori
阐明如何实现分子间相互作用强度微调的机制将有助于设计具有重要功能的分子。在本研究中，进行了理论分析，通过检查电子密度的变化，为两个卤素键合碘化系统，其卤素键的强度已被认为是增强的存在下的氢键捐助基团（称为氢键增强卤素键合）。结果表明，与静电势沿着C-I键延长线增强的预期相反，碘原子上电子分布的各向异性几乎保持不变。这意味着氢键和卤素键几乎独立地和附加地对静电势的增强做出贡献，表明这种增强的性质，并且在更一般的意义上，卤素键的方向性的强度和程度之间的关系。
Elucidating the mechanism of how we can achieve fine tuning of intermolecular interaction strength will be helpful for designing functionally important molecules. In the present study, a theoretical analysis is conducted, by examining the electron density changes, for two halogen-bonding iodinated systems whose halogen-bond strengths have been considered to be enhanced by the presence of a hydrogen-bond donating group (termed hydrogen-bond-enhanced halogen bonding). It is shown that, contrary to the expectation obtained from the enhancement of electrostatic potential along the line extended from the C–I bond, the anisotropy of electron distribution on the iodine atom remains nearly the same. This means that the hydrogen bond and halogen bond contribute almost independently and additively to the enhancement of electrostatic potential, indicating the nature of this enhancement and, in a more general sense, the relationship between the strength and the extent of directionality of halogen bonding.