Department of Chemistry, Lakehead University, Thunder Bay, Ontario, Canada.
J Phys Chem A. 2011 Nov 17;115(45):12544-54. doi: 10.1021/jp202757p. Epub 2011 Sep 7.
Substituent effects are ubiquitous in chemistry and the most fundamental is the inductive effect. In this study, the so-called inductive effect was probed in derivatives of bicyclo[1.1.1]pentane-1-carboxylic acid using the isodesmic reaction energy of the acid-base deprotonation, calculated at the PBE0/6-31++G(d,p) level of theory (used throughout). Although structure, molecular orbitals, and nuclear magnetic shielding parameters are discussed, the main focus of this study is the use of the quantum theory of atoms in molecules to analyze the electron density distribution. It was observed that the effect propagates via the manipulation of atomic dipole moments controlled by that of the substituent. As the dipole moment conforms to the principle of atomic transferability, it is found that the substituent dipole determined in simple systems (e.g., R-H) can be used to describe the effect upon the bicyclo[1.1.1]pentane-1-carboxylic acid system.
取代基效应在化学中无处不在，其中最基本的是诱导效应。在这项研究中，使用酸碱去质子化的等电子反应能量（在整个理论计算中都使用 PBE0/6-31++G(d,p) 水平），在双环[1.1.1]戊烷-1-羧酸衍生物中探究了所谓的诱导效应。尽管讨论了结构、分子轨道和核磁共振屏蔽参数，但本研究的主要重点是使用分子中原子的量子理论来分析电子密度分布。结果表明，这种效应通过原子偶极矩的操纵来传递，而原子偶极矩受取代基的控制。由于偶极矩符合原子可转移性原则，因此发现可以使用简单体系（例如 R-H）中确定的取代基偶极矩来描述对双环[1.1.1]戊烷-1-羧酸体系的影响。
