室温溶液における興奮状態の分子内チオール陽子の移転に関する章
Chun-Hsiang Wang1, Zong-Ying Liu1, Chun-Hao Huang2
1Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan (R.O.C.).
Journal of the American Chemical Society
|August 6, 2021
まとめ
研究者は初めて溶液中のチオール陽子の興奮状態内陽子移転 (ESIPT) を実験的に観察した. 硫黄を含むESIPT反応の新たな経路を明らかにした.
科学分野:
- 写真化学
- 超分子化学
- 有機化学
背景:
- 興奮状態のプロトン内移転 (ESIPT) は重要な光物理学的プロセスです.
- ESIPTは通常,O-HまたはN-Hの転送を含みますが,S-Hの転送はあまり調査されていません.
- ESIPTメカニズムを理解することは,新しい光反応材料の設計に不可欠です.
研究 の 目的:
- ティオール陽子を含む興奮状態の分子内陽子移転 (ESIPT) を実験的に実証する.
- 3-チオルフラボン誘導体,特に3NTFの光物理学的性質を調査する.
- 室温での硫黄を含む化合物のESIPTのメカニズムを解明する.
主な方法:
- 3NTFとそのメチル化同位体3MeNTFを含む3チオルフラボン誘導体の合成
- サイクロヘクサンの安定状態の吸収と放出スペクトロスコーピー
- 時間分解の光スペクトロスコーピー
- 計算化学のアプローチ (DFT)
主要な成果:
- 3NTFにおけるチオール型ESIPTの実験的観測は,710 nmでの大きなストークスシフト放射 (1,230 cm−1) によって証明された.
- 3MeNTFとの比較では,チオール陽子が欠け,472 nmで正常な放射を示している.
- 超高速のESIPT速度 (<180 fs) と3NTFのタウトメア放出寿命は120 psである.
- 計算による研究は,熱的に有利なESIPTを確認するが,非放射性誘導体の非放射性崩壊経路を明らかにする.
結論:
- 室温の溶液中のチオール型ESIPTに対する明確な実験的証拠
- 3NTFのダイエチラミノ群は,興奮状態でππ*特性を促進し,突出したタウトマー放出を可能にします.
- この研究は,非正規の硫黄水素結合を含むように,ESIPT化学の範囲を拡大する.
さらに関連する動画
11:09Constructing Thioether/Vinyl Sulfide-tethered Helical Peptides Via Photo-induced Thiol-ene/yne Hydrothiolation
Published on: August 1, 2018
10.9K
09:18Time-resolved ElectroSpray Ionization Hydrogen-deuterium Exchange Mass Spectrometry for Studying Protein Structure and Dynamics
Published on: April 17, 2017
10.0K
関連する概念動画
02:33Preparation and Reactions of Thiols
6.9K
Thiols are prepared using the hydrosulfide anion as a nucleophile in a nucleophilic substitution reaction with alkyl halides. For instance, bromobutane reacts with sodium hydrosulfide to give butanethiol.
6.9K
02:17Structure and Nomenclature of Thiols and Sulfides
5.2K
Thiols and sulfides are sulfur analogs of alcohols and ethers, respectively, where the sulfur atom takes the place of the oxygen atom. Thus, thiols are generally represented as RSH, where R is an alkyl substituent and —SH is the functional group. On the other hand, in sulfides, the central sulfur atom is bonded to two hydrocarbon groups on either side. Depending upon the type of group, sulfides can be either symmetrical or asymmetrical. Both thiols and sulfides display a bent geometry,...
5.2K
01:22Phase II Reactions: Glutathione Conjugation and Mercapturic Acid Formation
470
Glutathione, a tripeptide made up of glutamate, cysteine, and glycine, is a critical player in the detoxification of drugs and xenobiotics via a process known as glutathione conjugation or mercapturic acid formation. This phase II biotransformation reaction involves the covalent binding of glutathione to a drug or its metabolite, enhancing the compound's water solubility and enabling its excretion.
Several distinctive characteristics distinguish glutathione conjugation from other phase II...
Several distinctive characteristics distinguish glutathione conjugation from other phase II...
470
02:26Preparation and Reactions of Sulfides
5.3K
Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
5.3K
02:25SN1 Reaction: Mechanism
12.7K
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...
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...
12.7K
02:26SN2 Reaction: Transition State
10.5K
An SN2 reaction of an alkyl halide is a single-step process in which bond formation between the nucleophile and the substrate and bond breaking between the substrate and the halide occurs simultaneously through a transition state without forming an intermediate.
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
10.5K