関連する実験動画
Updated: Mar 3, 2026

08:04
Assembling Molecular Shuttles Powered by Reversibly Attached Kinesins
Published on: January 26, 2019
7.3K
ピリジル・アシル・ヒドラゾン・ロタキサンと分子シャトル
David A Leigh1, Vanesa Marcos1, Tugrul Nalbantoglu1
1School of Chemistry, University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
Journal of the American Chemical Society
|May 5, 2017
まとめ
研究者はピリジルアシルヒドラゾンを用いて,光/熱交換可能なロタキサンを開発した. これらの分子機械は 精密なマクロサイクルの動きを示し 先進的な分子シャトルへの道を切り開きます
科学分野:
- 超分子化学
- 有機化学
- 材料科学
背景:
- ロタキサンは,分子機械における潜在的応用を持つ,機械的に相互接続された分子である.
- ロタキサン軸のマクロサイクルの位置を制御することは,その機能にとって極めて重要です.
- 光 / 熱交換可能な分子は,分子組立と機能に対するダイナミックな制御を提供します.
研究 の 目的:
- 写真/熱交換可能なピリジル-アシルヒドラゾンの結合部位を特徴とする新しいロタキサンを合成し,特徴づけること.
- 水素ゾーン幾何学 (E/Z同位体) によるロタキサンのステレオ選択的形成を調査する.
- ロタキサン軸上のマクロサイクルの光と熱による制御可能な動きを実証する.
主な方法:
- ピリジル-アシルヒドラゾンの機能化された軸の合成.
- ベンジルアミドマクロサイクルのテンプレートによる自己組み立て
- X線結晶学を用いた特徴付け
- 紫外線照射による光異性化研究
- 熱スイッチング実験
主要な成果:
- [2]ロタキサンは,E-ヒドラゾンのイソメールをテンプレートとして使用して高収量 (最大85%) を形成した.
- Z-ヒドラゾンの同位体は,同様の条件下でロタキサンを生成しなかった.
- 紫外線照射でE-からZ-ロタキサンへの光異性化が98%達成された.
- X線結晶学では,E-およびZ-ロタキサンに対する明確な水素結合パターンが明らかになった.
- 分子シャトルでは,高位置整合性 (>95%) と切換精度 (98%) を有する制御されたマクロサイクル再定位が実証されました.
結論:
- ピリジル-アシルヒドラゾンの分子は,ロタキサン形成のための効果的な光/熱交換可能な結合部位として機能する.
- 水素ゾーンのE/Z幾何学は,指向されたマクロサイクルの組み立てに不可欠です.
- 光と熱は分子シャトルのマクロサイクルの位置を逆転的に制御し,ナノスケールデバイスの潜在能力を示します.
関連する概念動画
Radical Reactivity: Overview
2.9K
Radicals, the highly reactive species, gain stability by undergoing three different reactions. The first reaction involves a radical-radical coupling, in which a radical combines with another radical, forming a spin‐paired molecule. The second reaction is between a radical and a spin‐paired molecule, generating a new radical and a new spin‐paired molecule. The third reaction is radical decomposition in a unimolecular reaction, forming a new radical and a spin‐paired...
2.9K
Woodward–Hoffmann Selection Rules and Microscopic Reversibility
4.1K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
4.1K
Cycloaddition Reactions: MO Requirements for Thermal Activation
4.9K
Thermal cycloadditions are reactions where the source of activation energy needed to initiate the reaction is provided in the form of heat. A typical example of a thermally-allowed cycloaddition is the Diels–Alder reaction, which is a [4 + 2] cycloaddition. In contrast, a [2 + 2] cycloaddition is thermally forbidden.
4.9K
Radical Reactivity: Intramolecular vs Intermolecular
2.3K
Radical reactions can occur either intermolecularly or intramolecularly. In an intermolecular radical reaction, a nucleophilic radical adds to an electrophilic alkene or vice versa. In such reactions, the radical and generally the alkene, which is also called the radical trap, are two different molecules. Additionally, for such intermolecular reactions to occur, the radical trap must be active, present in an excess concentration, and the radical starting material must have a weak...
2.3K
Radical Formation: Overview
2.7K
A bond can be broken either by heterolytic bond cleavage to form ions or homolytic bond cleavage to yield radicals. A fishhook arrow is used to represent the motion of a single electron in homolytic bond cleavage. There are two main sources from which radicals can be formed:
Radicals from spin-paired molecules:
Radicals can be obtained from spin-paired molecules either by homolysis or electron transfer. While two radicals are formed in the former, an electron is added in the...
Radicals from spin-paired molecules:
Radicals can be obtained from spin-paired molecules either by homolysis or electron transfer. While two radicals are formed in the former, an electron is added in the...
2.7K
Chair Conformation of Cyclohexane
20.2K
The chair conformation is the most stable form of cyclohexane due to the absence of angle and torsional strain. The absence of angle strain is a result of cyclohexane’s bond angle being very close to the ideal tetrahedral bond angle of 109.5° in its chair conformer. Similarly, the torsional strain is also absent owing to the perfectly staggered arrangement of bonds.
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this...
20.2K

