基与氧基基相比:对 σ-电子移位的构成效应
Milena Jovanovic1, Josef Michl1,2
1Department of Chemistry, University of Colorado, Boulder, Colorado 80309-0215, United States.
Journal of the American Chemical Society
|December 29, 2021
概括
基和寡基基因由于电子负性而表现出不同的西格玛电子移位. 是一种,是一种.
科学领域:
- 计算化学计算化学
- 材料科学 材料科学 材料科学
- 有机化学 有机化学
背景情况:
- 了解和链中的西格玛电子移位对于预测分子性质至关重要.
- 基 (CnH2n) 和基基 (SinnH2n+2) 是异电子和异类的类似物,提供了一个比较研究平台.
- 电子结构的形态依赖会影响化学反应性和物理特性.
研究的目的:
- 为了研究和比较sigma电子移位在基和寡基基中的构造依赖性.
- 为了阐明在移位行为中观察到的差异的潜在电子原因.
- 开发一个直观的模型来理解这些构造效应.
主要方法:
- 使用Hückel级扩展梯子哈密尔顿模型对近似代数解的分析.
- 利用一个洞的有效质量作为西格玛电子移位的定量度量.
- 模型参数化涉及适应密度函数理论 (DFT) 和哈特里-福克 (HF) 计算结果.
主要成果:
- 在基和寡基基之间观察到西格玛电子移位的程度和形状依赖的显著差异.
- 发现了两个移位模式:对形状敏感的骨移位 (X-X键) 和不太敏感的横向移位 (X-H键).
- 由于互补模式,基体在所有构造中都表现出脱位;寡基体主要表现出洞的骨架脱位,强烈依赖构造.
结论:
- 与碳和相比,和之间的电子负性差异是明显的移位模式的主要原因.
- 一个简化的梯子模型足够地描述了寡基中强烈的形状依赖.
- 这项研究为基于的材料的电子结构及其结构灵活性提供了基本的见解.
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