不同基组的诱导效应有没有趋势?
Mark C Elliott1, Colan E Hughes1, Peter J Knowles1
1School of Chemistry, Cardiff University Park Place Cardiff CF10 3AT UK elliottmc@cardiff.ac.uk.
这项研究没有发现使用希尔什菲尔德电荷分析的常见基基的诱导效应有显著差异. 基团的电子负性与电子捐赠或提取能力无关,这表明赫什菲尔德电荷在电荷分布分析中更可靠.
科学领域:
- 计算化学是一种计算化学.
- 有机化学 有机化学
背景情况:
- 了解基团的电子作用在有机化学中至关重要.
- 传统的方法,如电子阴性,可能不能准确地反映电荷分布.
研究的目的:
- 为了比较四个代表性基团的诱导效应.
- 为了评估基组属性及其电子影响之间的相关性.
- 确定希什菲尔德电荷分析与评估电荷分布的其他方法相比的可靠性.
主要方法:
- 希尔什菲尔德电荷分析被用来量化电荷分布.
- 计算的电荷在不同的基组之间进行了比较.
- 评估了基组电子阴性值的相关性.
主要成果:
- 通过希尔什菲尔德分析,在研究的基组的诱导作用中没有观察到显著的差异.
- 基组的电子阴性与电子捐赠/提取能力的相关性很差.
- 在13C NMR化学转移和计算的希尔什菲尔德电荷之间注意到了显著的分歧.
结论:
- 希尔什菲尔德电荷分析提供了比基组电子阴性更可靠的电荷分布测量方法.
- 13C NMR 化学转移可能不会直接反映由希尔什菲尔德电荷表示的电子效应.
更多相关视频
07:30A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones
Published on: January 21, 2020
06:46Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
相关概念视频
Inductive Effects on Chemical Shift: Overview
Isomerism in Alkenes
An isomer is called cis-2-butene when the methyl groups are on the same side of the double bond, and the other stereoisomer, in which methyl groups are on the opposite side of the double bond, is called trans-2-butene. The cis and trans stereoisomers are not...
Relative Stabilities of Alkenes
Electrophilic Addition to Alkynes: Halogenation
Halogenation is another class of electrophilic addition reactions where a halogen molecule gets added across a π bond. In alkynes, the presence of two π bonds allows for the addition of two equivalents of halogens (bromine or chlorine). The addition of the first halogen molecule forms a trans-dihaloalkene as the major product and the cis isomer as the minor product. Subsequent addition of the second equivalent yields the tetrahalide.
Alkyl Halides
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
