関連する実験動画
Updated: May 14, 2026

10:52
Direct Imaging of Laser-driven Ultrafast Molecular Rotation
Published on: February 4, 2017
分子の誕生とそれに伴う溶媒の再配置を撮影する
Jae Hyuk Lee1, Michael Wulff, Savo Bratos
1Center for Time-Resolved Diffraction, Department of Chemistry, KAIST, Daejeon 305-701, Republic of Korea.
Journal of the American Chemical Society
|February 5, 2013
まとめ
新しく形成された分子は,周りの溶媒分子にエネルギーを転送することにより,溶液で急速に冷却されます. ピコ秒X線流体撮影は,この振動のリラックスプロセス中に分子および溶媒ケージの構造変化を視覚化しました.
科学分野:
- 物理化学 物理化学
- 化学物理 化学物理
- マテリアルサイエンス 材料科学
背景:
- 分子はしばしば過剰なエネルギーと大きな振動で形成されます.
- 分子冷却には,溶媒分子へのエネルギー分散が不可欠である.
- リラクゼーション中の溶解物-溶媒のダイナミクスを理解することは困難です.
研究 の 目的:
- 分子振動のリラックス中に時間依存の構造変化を視覚化するために.
- 冷却溶液の周りの溶媒分子の再配置を調査する.
- 原子間距離と溶解構造の進化をマッピングする.
主な方法:
- ピコ秒のX線液体撮影 (溶液散布) を利用した.
- ヨウ素 (I2) 分子の振動のリラックスを研究した.
- 炭酸四塩化物 (CCl4) とサイクロヘキサン溶媒における研究されたダイナミクス.
主要な成果:
- 原子間距離分布の時間的な変化をマッピングした.
- 観測されたI-I結合距離は ~4 Å に増加し,その後,リラクゼーションは 2.67 Å になりました.
- I-I軸に沿って第1ソルベーションケージの ~1.5 Å の膨張と収縮が記録されています.
結論:
- 分子冷却のダイナミクスに関する前例のない構造的洞察を提供した.
- 溶質の振動リラックスと溶媒ケージの再配置との結合を実証した.
- 溶液中の超高速分子プロセスを探査するためのX線液体写真の有用性を強調した.
関連する概念動画
Thermal Sigmatropic Reactions: Overview
Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in 1,5-hexadiene, referred to as...
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in 1,5-hexadiene, referred to as...
SN1 Reaction: Mechanism
Kinetic studies of ionization of a tertiary halide in a protic solvent suggest that only the substrate participates in the rate-determining step (slow step). The nucleophile is involved only after the slowest step. The SN1 reaction takes place in a multiple-step mechanism.
Firstly, the haloalkane ionizes to generate a carbocation intermediate and a halide ion. This heterolytic cleavage is highly endothermic with large activation energy. The ionization of the substrate, facilitated by a polar...
Firstly, the haloalkane ionizes to generate a carbocation intermediate and a halide ion. This heterolytic cleavage is highly endothermic with large activation energy. The ionization of the substrate, facilitated by a polar...
Formation of Halohydrin from Alkenes
An alkene, such as propene, reacts with bromine in the presence of water to yield a halohydrin. Halohydrins contain a halogen and a hydroxyl group attached to adjacent carbons. When the halogen is bromine, it is called a bromohydrin, while a chlorohydrin has chlorine as the halogen.
Fast Reactions
Fast reactions occurring in times shorter than the time needed to mix reactants pose a unique challenge for investigation. In a liquid-phase continuous-flow system, reactants A and B are swiftly pushed into the mixing chamber, where mixing occurs within 1 ms. The reaction mixture then flows through an observation tube, and one measures light absorption to determine species concentrations at various points of the tube. This method is most appropriate when relatively large volumes of reactants...
[3,3] Sigmatropic Rearrangement of Allyl Vinyl Ethers: Claisen Rearrangement
The Claisen rearrangement is a [3,3] sigmatropic rearrangement of allyl vinyl ethers to unsaturated carbonyl compounds. The rearrangement is a concerted pericyclic reaction proceeding via a chair-like transition state.
[3,3] Sigmatropic Rearrangement of 1,5-Dienes: Cope Rearrangement
The Cope rearrangement is classified as a [3,3] sigmatropic shift in 1,5-dienes, leading to a more stable, isomeric 1,5-diene. The reaction involves a concerted movement of six electrons, four from two π bonds and two from a σ bond, via an energetically favorable chair-like transition state.

