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首页> 外文期刊>The journal of physical chemistry, A. Molecules, spectroscopy, kinetics, environment, & general theory >Density Functional Theory and Atoms-in-Molecules Investigation of Intramolecular Hydrogen Bonding in Derivatives of Malonaldehyde and Implications for Resonance-Assisted Hydrogen Bonding
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Density Functional Theory and Atoms-in-Molecules Investigation of Intramolecular Hydrogen Bonding in Derivatives of Malonaldehyde and Implications for Resonance-Assisted Hydrogen Bonding

机译：丙二醛衍生物分子内氢键的密度泛函理论和分子内原子研究及其共振辅助氢键的意义

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摘要

A density functional theory(DFT)and atoms-in-molecules(AIM)analysis has been applied to the intramolecular hydrogen bonding in the enol conformers of malonaldehyde and its fluoro-,chloro-,cyano-,and nitro-substituted derivatives.With the B3LYP/6-311++G(2d,p)method,good agreement between the DFT geometries and published experimental structures has been found.The donor-acceptor distance was also varied in a series of constrained optimizations in order to determine if energetic,structural,and topological trends associated with intermolecular hydrogen bonding remain valid in the intramolecular case.At very short donor-acceptor distances(<2.24 A),the hydrogen is symmetrically located between donor and acceptor;at distances longer than this,the hydrogen bonding is no longer symmetric.The AIM methodology has been applied to explore the topology of the electron density in the intramolecular hydrogen bonds of the chosen model systems.Most AIM properties for intramolecular hydrogen bond distances longer than 2.24 A show smooth trends,consistent with intermolecular hydrogen bonds.Integrated AIM properties have also been used to explore the phenomenon of resonance-assisted hydrogen bonding(RAHB).It is shown that as the donor-acceptor distance is varied,pi-electron density is redistributed among the carbon atoms in the intramolecular hydrogen bond ring;however,contrary to prior studies,the integrated atomic charges on the donor-acceptor atoms were found to be insensitive to variation of hydrogen-bonding distance.
机译：密度泛函理论（DFT）和分子内原子（AIM）分析已应用于丙二醛及其氟，氯，氰基和硝基取代的衍生物的烯醇构象中的分子内氢键。 B3LYP / 6-311 ++ G（2d，p）方法，已发现DFT几何形状与已发布的实验结构之间具有良好的一致性。在一系列受约束的优化过程中，供体-受体的距离也发生了变化，以确定能量是否充足，在分子内情况下，与分子间氢键相关的结构和拓扑趋势仍然有效。在非常短的供体-受体距离（<2.24 A）下，氢对称地位于供体和受体之间;在更长的距离上，氢键为不再对称.AIM方法已用于探索所选模型系统分子内氢键中电子密度的拓扑结构。分子内氢键距离的大多数AIM特性大于2.24 A的原子显示出平滑的趋势，与分子间氢键一致。还利用集成的AIM特性研究了共振辅助氢键（RAHB）的现象。结果表明，随着供体-受体距离的变化，pi -电子密度在分子内氢键环中的碳原子之间重新分布;但是，与先前的研究相反，发现供体-受体原子上的积分原子电荷对氢键合距离的变化不敏感。

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