Oliveira de Sousa David Wilian, Nascimento Marco Antonio Chaer
Instituto de Química, Universidade Federal do Rio de Janeiro , 21949-900 Rio de Janeiro, Brazil.
J Phys Chem A. 2018 Feb 8;122(5):1406-1412. doi: 10.1021/acs.jpca.7b11760. Epub 2018 Jan 25.
The interference energy partitioning analysis method developed by our group and used to study the nature of the chemical bond was extended to partition the electric dipole moment in quasi-classical and interference contributions. Our results show that interference participates in charge displacement in polar molecules, providing, directly or indirectly, a relevant contribution for the total dipole moment. A linear correlation was found between the interference contribution of the dipole moment from the bond electron group, μ(bond), and the difference of electronegativity of the atoms which form the bond, ΔX. This interesting result reinforces the fact that electronegativity is not a property of an atom alone, but rather a property of the atom in the molecule and that ΔX can only be associated with that part of the total charge displacement resulting from the formation of the chemical bond. The partitioning of the total dipole moment into quasi-classical and interference contributions provides new insights about the reasons for the failure of the ΔX criterion in predicting the correct orientation of the dipole moment in several molecules. The results of the present work also bring additional evidence for the previously proposed mechanism of formation of polar bonds.
我们团队开发的用于研究化学键性质的干涉能量划分分析方法，被扩展用于将电偶极矩划分为准经典贡献和干涉贡献。我们的结果表明，干涉参与了极性分子中的电荷位移，直接或间接地对总偶极矩做出了相关贡献。发现键电子基团的偶极矩干涉贡献μ(bond)与形成该键的原子的电负性差值ΔX之间存在线性相关性。这一有趣结果强化了以下事实：电负性并非单个原子的性质，而是分子中原子的性质，并且ΔX仅能与化学键形成导致的总电荷位移的那部分相关联。将总偶极矩划分为准经典贡献和干涉贡献，为ΔX准则在预测多个分子中偶极矩正确取向时失效的原因提供了新的见解。本工作的结果也为先前提出的极性键形成机制带来了更多证据。
