![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
PCETベースのリガンド制限電荷再結合とIr (III) フォトレドックス触媒
Hannah Sayre1, Hunter H Ripberger1, Emmanuel Odella2
1Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.
Journal of the American Chemical Society
|August 11, 2021
まとめ
この研究では,分子内プロトン結合電子移転 (PCET) を使用して,光システムIIにインスパイアされた新しい光触媒を導入し,電荷再結合を大幅に減少させます. この強化により,光還元触媒の反応効率が向上する.
科学分野:
- 写真化学
- カタリシス
- 有機化学
背景:
- 電荷再結合は,光還元反応の重要な制限であり,量子出力を減少させます.
- 陽子結合電子伝送 (PCET) 機構は,光システムIIのような自然系で観察され,これを緩和するための潜在的な戦略を提供します.
- イリジウム複合体は,光触媒として広く使用されているが,その効率は,急速な電荷再結合によって妨げられる.
研究 の 目的:
- ベンジミダゾールフェノール (BIP) を含んだ新しいイリジウム光触媒の設計と合成.
- 刺激された光触媒における電荷再結合率に対する分子内PCETの影響を調査する.
- モデルフォトレドックス反応の効率に対する減少電荷再結合の影響を評価する.
主な方法:
- ベンジミダゾールフェノール (BIP) ユニットとイリジウム複合体の2,2'-ビピリジルリガンドの共性結合 ([Ir(dF(CF3) ppy) 2 ((bpy)) [PF6]).
- 改変されたイリジウム複合体の光刺激により,分子内PCETを誘導し,電荷分離状態を形成する.
- 電荷分離状態と電子移転のダイナミクスを分析するスペクトル学と電気化学の研究.
- メチルバイオゲンディケーション (MV2+) を代替基質として使用した修正された触媒を用いたフタリミドエステルの光触媒的還元.
主要な成果:
- 改造された光触媒 ([Ir(dF(CF3)ppy) 2 ((BIP-bpy) [PF6]) は,光刺激により分子内PCETに成功する.
- BIPの部分の存在は,約24倍にチャージ再結合率を大幅に遅らせます.
- この電荷再結合の減少は,フタリミドエステル還元の量子効率の2倍以上の増加をもたらした.
結論:
- 自然システムにインスパイアされた分子内PCETは,イリジウム光触媒における電荷再結合を抑制する効果的な戦略です.
- 設計されたBIP機能化されたイリジウム複合体は,電荷分離の改善により,光還元触媒の性能が向上しています.
- このアプローチは,様々な有機変異のためのより効率的な光触媒を開発するための有望な経路を提供します.
さらに関連する動画
09:45Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene
Published on: March 20, 2017
10.6K
![Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F51444.jpg&w=3840&q=50)
11:44Mizoroki-Heck Cross-coupling Reactions Catalyzed by Dichloro{bis[1,1',1''-phosphinetriyltripiperidine]}palladium Under Mild Reaction Conditions
Published on: March 20, 2014
25.6K
関連する概念動画
01:26Photochemical Electrocyclic Reactions: Stereochemistry
2.0K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
2.0K
01:17Thermal Electrocyclic Reactions: Stereochemistry
2.2K
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.
2.2K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.6K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.6K
01:12Cycloaddition Reactions: MO Requirements for Photochemical Activation
2.3K
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
2.3K
02:51Metal-Ligand Bonds
22.5K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
22.5K
01:17Pericyclic Reactions: Introduction
8.6K
Pericyclic reactions are organic reactions that occur via a concerted mechanism without generating any intermediates. The reactions proceed through the movement of electrons in a closed loop to form a cyclic transition state, where rearrangement of the σ and π bonds yields specific products.
Pericyclic reactions can be classified into three categories: electrocyclic reactions, cycloaddition reactions, and sigmatropic rearrangements. Electrocyclic reactions and sigmatropic...
Pericyclic reactions can be classified into three categories: electrocyclic reactions, cycloaddition reactions, and sigmatropic rearrangements. Electrocyclic reactions and sigmatropic...
8.6K