相关实验视频

Updated: Jun 17, 2025

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents

A Protocol for Safe Lithiation Reactions Using Organolithium Reagents

Published on: November 12, 2016

化的选择性离子对识别由异种类型的 [2] 罗塔克桑

Vihanga K Munasinghe¹, Hui Min Tay¹, Dilhan Manawadu²

¹Department of Chemistry, University of Oxford, Chemistry Research Laboratory Mansfield Road, Oxford OX1 3TA, UK. paul.beer@chem.ox.ac.uk.

Dalton transactions (Cambridge, England : 2003)

|August 8, 2024

概括

研究人员开发了新型的罗他素宿主,用于强烈而选择性的化结合. 一个合作机制在阴离子复合时增强了离子亲和力,使精确的离子对识别成为可能.

科学领域:

超分子化学超分子化学
主机和客人的化学反应
有机化学有机化学

背景情况:

开发选择性宿主分子对于离子识别至关重要.
罗塔克桑为分子设计提供独特的机械互锁结构.
离子结合对于电池和传感器来说很重要.

研究的目的:

设计和合成新型异种类型的 [2]rotaxane宿主.
研究化离子对的结合机制和选择性.
探索宿主-客人复杂化中的合作效应.

主要方法:

具有明显的阴离子和阴离子结合位点的轮素结构的合成.
定量1HNMR定位研究以确定结合亲和性和选择性.
进行X射线晶体学和密度函数理论 (DFT) 计算,以获得结构和机械的洞察力.

主要成果:

开发出了第一个能够强烈和选择性化离子对结合的异种类型[2]rotaxane宿主.
观察到一种合作的"开启"机制,其中阴离子结合增强了阴离子亲和力.
量化了对化比化或化的增强结合亲和力.
水素结合 (HB) 轮素对化具有明显的选择性.
结构研究证实了轴分离的离子对结合模式.

结论:

这些罗他素系统代表了选择性离子对识别的重大进步.
合作结合机制为设计复杂的分子识别系统提供了一个新的策略.
这些发现在需要选择性离子检测或分离的领域有潜在的应用.

更多相关视频

1,3,5-Triphenylbenzene and Corannulene as Electron Receptors for Lithium Solvated Electron Solutions

1,3,5-Triphenylbenzene and Corannulene as Electron Receptors for Lithium Solvated Electron Solutions

Published on: October 10, 2016

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene

Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene

Published on: March 20, 2017

相关概念视频

Acid Halides to Ketones: Gilman Reagent

Acid Halides to Ketones: Gilman Reagent

Lithium dialkyl cuprate, also known as Gilman reagents, selectively reduces acid halides to ketones. The acid chloride is treated with Gilman reagent at −78 °C in the presence of ether solution to produce a ketone in good yield.
As shown below, the mechanism proceeds in two steps. First, one of the alkyl groups of the reagent acts as a nucleophile and attacks the acyl carbon of the acid chloride to form a tetrahedral intermediate. This is followed by the reformation of the carbon–oxygen...

Thermal Electrocyclic Reactions: Stereochemistry

Thermal Electrocyclic Reactions: Stereochemistry

The stereochemistry of electrocyclic reactions is strongly influenced by the orbital symmetry of the polyene HOMO. Under thermal conditions, the reaction proceeds via the ground-state HOMO.
Selection Rules: Thermal Activation
Conjugated systems containing an even number of π-electron pairs undergo a conrotatory ring closure. For example, thermal electrocyclization of (2E,4E)-2,4-hexadiene, a conjugated diene containing two π-electron pairs, gives trans-3,4-dimethylcyclobutene.

Ion-Exchange Chromatography

Ion-Exchange Chromatography

Ion-exchange chromatography, or IEC, is a technique for separating ions based on their affinity for the stationary phase. The stationary phase is a cross-linked polymer resin with covalently attached ionic functional groups. The functional groups can be either positively charged (cation exchangers) or negatively charged (anion exchangers). A cation exchanger consists of a polymeric anion and active cations, while an anion exchanger is a polymeric cation with active anions. The choice of...

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule

If a set of reactants can yield multiple constitutional isomers, but one of the isomers is obtained as the major product, the reaction is said to be regioselective. In such reactions, bond formation or breaking is favored at one reaction site over others.
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...

Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration

Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration

The rate of acid-catalyzed hydration of alkenes depends on the alkene's structure, as the presence of alkyl substituents at the double bond can significantly influence the rate.

Ion Exchange

Ion Exchange

Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or...