関連する実験動画
Updated: Jun 30, 2026
06:15
Interactive Molecular Model Assembly with 3D Printing
Published on: August 13, 2020
ロタキサン基の分子シャトルにおけるイミンと水素結合ステーションの間のマクロサイクルのエントロピーおよび水解性駆動のポジショナルスイッチング
Takeshi Umehara1, Hidetoshi Kawai, Kenshu Fujiwara
1Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan.
Journal of the American Chemical Society
|September 27, 2008
まとめ
この研究では,イミン結合ステーションを備えた新しい分子シャトルが報告されています. これらのシャトルは,エントロピー駆動のスイッチングによる制御されたマクロサイクルの動きを示し,イミンと水素結合のシナジーを強調しています.
科学分野:
- 超分子化学 超分子化学
- マテリアルサイエンス 材料科学
- 有機化学 オーガニック・ケミストリー
背景:
- 分子シャトルは,高度な分子機械の開発に不可欠です.
- 分子構成要素の位置を制御することは,その機能の鍵です.
- イミンと水素結合は,分子組立とスイッチングのための多用途な戦略を提供します.
研究 の 目的:
- イミン結合ステーションを利用した新種の分子シャトルを設計・合成する.
- これらの新しい分子シャトルのスイッチング特性と位置制御を調査する.
- シャトルの行動を支配する熱力学的原理を明らかにする.
主な方法:
- 異なるステーション機能 (TEGステーション) を有するイミンブリッジド [2]ロタキサンの合成.
- マクロサイクル運動を誘発および制御するための酸性水解および脱水条件.
- ポジショナル・スイッチングの背後にある原動力を理解するための熱力学分析.
主要な成果:
- イミン結合ステーションを備えた分子シャトルの建設に成功.
- イミン状態と水素結合状態の間の制御されたマクロサイクルのシャトルの実証.
- 高い位置差別のエントロピー駆動型トランスレーションイソメリスムの識別.
- イミン水解と水素結合形成の熱力学的マッチングにより,効率的なスイッチングが可能です.
結論:
- イミンと水素結合ステーションの組み合わせにより,ロタキサン系におけるマクロサイクルの位置を正確に制御できます.
- これらの分子シャトルは,エントロピー主導のポジショナル・スイッチングを顕著に示し,高度な分子装置のためのプラットフォームを提供している.
- この発見は,機能的な分子機械の設計原理に関する根本的な洞察を提供します.
関連する概念動画
02:02Chair Conformation of Cyclohexane
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 staggered...
The hydrogen atoms linked to carbons are arranged in two different axial and equatorial orientations to achieve this staggered...
02:30Stability of Substituted Cyclohexanes
This lesson discusses the stability of substituted cyclohexanes with a focus on energies of various conformers and the effect of 1,3-diaxial interactions.
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
The two chair conformations of cyclohexanes undergo rapid interconversion at room temperature. Both forms have identical energies and stabilities, each comprising equal amounts of the equilibrium mixture. Replacing a hydrogen atom with a functional group makes the two conformations energetically non-equivalent.
For example, in...
00:52¹H NMR of Conformationally Flexible Molecules: Temporal Resolution
At room temperature, the chair conformer of cyclohexane undergoes rapid ring flipping between two equivalent chair conformers at a rate of approximately 105 times per second. These two chair conformers are in equilibrium. The rapid ring flipping results in the interconversion of the axial proton to an equatorial proton and an equatorial to the axial proton. Such interconversions are too rapid and cannot be detected on the NMR timescale. Hence, the NMR spectrometer cannot distinguish between the...
02:11Conformations of Cyclohexane
Cyclohexane does not exist in a planar form due to the high angle and torsional strain it would experience in the planar structure. Instead, it adopts non-planar chair and boat conformations.
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
The chair form is the most stable and derives its name from its resemblance to the “easy chair.” In the chair conformation, two carbon atoms are arranged out-of-plane — one above and one below, minimizing the torsional strain. In the chair form, the bond angle is very close to the ideal tetrahedral value,...
01:34Woodward–Hoffmann Selection Rules and Microscopic Reversibility
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...
01:17Thermal 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.
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.