Alpha effect
≈ 2 min read
Names in other languages
- DeutschAlpha-Effekt
- EnglishAlpha effect
- caEfecte alfa
- NederlandsAlfa-effect
- УкраїнськаАльфа-ефект
- 中文邻位效应
- 繁體中文鄰位效應
- 日本語Α効果
Article bodies are English and are not machine-translated. A name in another language is not a translation of the article.
The alpha effect refers to the increased nucleophilicity of an atom due to the presence of an adjacent (alpha) atom with lone pair electrons. This first atom does not necessarily exhibit increased basicity compared with a similar atom without an adjacent electron-donating atom, resulting in a deviation from the classical Brønsted-type reactivity-basicity relationship. In other words, the alpha effect refers to nucleophiles presenting higher nucleophilicity than the predicted value obtained from the Brønsted basicity. The representative examples would be high nucleophilicities of hydroperoxide (HO 2 − ) and hydrazine (N 2 H 4 ). The effect is now well established with numerous examples and became an important concept in mechanistic chemistry and biochemistry. However, the origin of the effect is still controversial without a clear winner.
The alpha effect refers to the increased nucleophilicity of an atom due to the presence of an adjacent (alpha) atom with lone pair electrons. This first atom does not necessarily exhibit increased basicity compared with a similar atom without an adjacent electron-donating atom, resulting in a deviation from the classical Brønsted-type reactivity-basicity relationship. In other words, the alpha effect refers to nucleophiles presenting higher nucleophilicity than the predicted value obtained from the Brønsted basicity. The representative examples would be high nucleophilicities of hydroperoxide (HO 2 − ) and hydrazine (N 2 H 4 ). The effect is now well established with numerous examples and became an important concept in mechanistic chemistry and biochemistry. However, the origin of the effect is still controversial without a clear winner.
Text derived from https://en.wikipedia.org/w/index.php?oldid=1350261466 under CC BY-SA 4.0; modifications have been made.