穆勒与古特曼 - 贝克特对玻酸的易斯酸度的评估
Sameera Ranasinghe1, Yijie Li1, Madison E Andrews1
1Department of Chemistry and Biochemistry, Baylor University, One Bear Place #97348, Waco, TX 76798, USA. caleb_d_martin@baylor.ed.
Chemical communications (Cambridge, England)
|June 12, 2025
概括
这项研究引入了p-fluorobenzonitrile作为一种新的19F核磁共振探头,用于评估酸的易斯酸度. 新的尺度与既有方法和计算数据保持一致,为化学家提供了有价值的工具.
科学领域:
- 有机金属化学 有机金属化学
- 频谱学是一种光谱学.
- 计算化学的计算化学
背景情况:
- 易斯酸度是烯的基本特性,对于理解它们的反应性至关重要.
- 目前用于量化易斯酸度的方法,例如古特曼-贝克特尺度,有局限性.
- 核磁共振 (NMR) 谱学提供了对易斯酸相互作用的敏感检测.
研究的目的:
- 开发和验证一种新的光谱方法,用于确定酸的相对易斯酸度.
- 为了引入*p*-fluorobenzonitrile (PFBN) 作为易斯酸添加物的F NMR探针.
- 为了将新的基于PFBN的易斯酸度表与既有方法和计算数据进行比较.
主要方法:
- 采用核磁共振 (NMR) 光谱法,使用*p*-fluorobenzonitrile作为探针.
- 测量了PFBN在与各种酸盐一起形成 adduct 时的化学转移变化.
- 由此产生的易斯酸度尺度与已建立的古特曼-贝克特尺度 (使用P NMR) 进行比较,并计算了化物亲和力.
主要成果:
- 通过PFBN的F NMR建立了一个可靠的易斯相对酸度尺度,用于一系列烯.
- 基于PFBN的尺度与古特曼-贝克特尺度有很好的相关性.
- 实验数据与计算的化物亲和力强烈一致,验证了新方法.
结论:
- *p*-Fluorobenzonitrile是一种有效的FNMR探针,用于量化酸的易斯酸度.
- 这种方法为现有技术提供了一个补充和潜在的优势替代方案.
- 这项研究验证了F NMR在有机金属化学中的易斯酸度测量中的使用.
更多相关视频
相关概念视频
02:16Lewis Acids and Bases
13.9K
This lesson delves into Lewis acids and bases in the context of the octet rule for electron-deficient compounds. Here, the concept is discussed, emphasizing the group 13 elements like boron or aluminium. Since group 13 elements possess three valence electrons, they form trivalent compounds with a sextet of electrons and a vacant orbital for the central atom. Consequently, these electron-deficient compounds accept electrons from other species to complete their octet in a chemical reaction. They...
13.9K
03:08Hydroboration-Oxidation of Alkenes
8.0K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
8.0K
02:36Regioselectivity and Stereochemistry of Hydroboration
8.1K
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn...
8.1K
03:51Molecular Orbital Theory II
19.0K
Molecular Orbital Energy Diagrams
19.0K
02:27Predicting Molecular Geometry
34.1K
VSEPR Theory for Determination of Electron Pair Geometries
34.1K
02:16Brønsted-Lowry Acids and Bases
19.0K
In 1923, the Brønsted–Lowry definition of acids and bases was proposed by Johannes Brønsted and Thomas Lowry. According to this theory, a Brønsted acid is defined as a species that donates a proton in a chemical reaction and gets converted to its conjugate base. A Brønsted base is defined as a species that accepts a proton in a chemical reaction and gets converted into its conjugate acid. These transfers of protons are caused by the displacement of electrons in these reactions, which is...
19.0K