Suppr超能文献

使用轨道力和非共价相互作用分析 CH 中的构象偏好;与相关系统的比较。

Conformational preference analysis in CH using orbital forces and non-covalent interactions; comparison with related systems.

机构信息

Laboratoire de Chimie Théorique (LCT) Sorbonne Université, CNRS, 4, Place Jussieu, F-75005, Paris, France.

出版信息

Phys Chem Chem Phys. 2023 Feb 1;25(5):4276-4283. doi: 10.1039/d2cp04913a.

Abstract

Dynamic Orbital Forces (DOF) and Non-Covalent Interactions (NCIs) are used to analyze the attractive/repulsive interactions responsible of the conformational preference of ethane and some related compounds. In ethane, it is found that the stabilization of the staggered conformation with respect to the adiabatic eclipsed one arises from both attractive and repulsive interactions in CH⋯CH. Attractive ones are predominant in a ratio 2 : 1, with an important role of a σ MO. On the contrary, the stabilization of the staggered conformation with respect to the vertical eclipsed one arises almost only from repulsive π interactions. Weak long-range H⋯H repulsions also favour the staggered conformation. From the sum of DOFs, yielding intrinsic bond energies, the rotation barrier can be decomposed into a weakening of the C-C bond ( 7 kcal mol), moderated by a strengthening of C-H ones ( 4 kcal mol). This evidences the decrease of hyperconjugation in the eclipsed conformation with respect to the staggered one. In the compounds CH-SiH, SiH-SiH, CH-CF and CF-CF, the conformational preference is predominantly or exclusively due to repulsive interactions, with respect as well to adiabatic as to vertical eclipsed structures.

摘要

动态轨道力(DOF)和非共价相互作用(NCIs)用于分析导致乙烷和一些相关化合物构象偏好的吸引力/排斥力。在乙烷中,发现 CH⋯CH 中的吸引和排斥相互作用导致了交错构象相对于绝热重叠构象的稳定。吸引相互作用占主导地位,比例为 2:1,其中σ MO 起着重要作用。相反,交错构象相对于垂直重叠构象的稳定主要来自于排斥的π相互作用。较弱的远程 H⋯H 排斥也有利于交错构象。从产生固有键能的 DOF 总和来看,可以将旋转势垒分解为 C-C 键的削弱(7 kcal mol),由 C-H 键的增强(4 kcal mol)来调节。这证明了在重叠构象中与交错构象相比超共轭作用的减少。在 CH-SiH、SiH-SiH、CH-CF 和 CF-CF 等化合物中,构象偏好主要或完全归因于排斥相互作用,无论是对于绝热还是垂直重叠结构。

文献AI研究员

20分钟写一篇综述,助力文献阅读效率提升50倍。

立即体验

用中文搜PubMed

大模型驱动的PubMed中文搜索引擎

马上搜索

文档翻译

学术文献翻译模型,支持多种主流文档格式。

立即体验