非ヘム鉄 (V) -オクソ複合結合陽子の強化レドックス反応性
Shan-Shan Xue1, Xiao-Xi Li1, Yong-Min Lee1
1Department of Chemistry and Nano Science, Ewha Womans University, Seoul 03760, Korea.
Journal of the American Chemical Society
|August 14, 2020
まとめ
陽子化は,酸素原子移転および電子移転反応における鉄 (V) -オクソ複合体の反応性を劇的に高めます. この研究は,プロトン化鉄 (V) -オクソテトラアミドマクロサイクルリガンド複合体の合成と反応性を詳細に説明する.
科学分野:
- 協調化学
- バイオ有機化学
- 酸化触媒
背景:
- 金属と酸素の中間物質に対する酸の作用は,酸化還元反応を理解するために重要である.
- 高価金属-オクソ種の反応性は,しばしばプロトネーションまたはルイス酸結合によって強化される.
- 鉄酸化複合体は生物学的および工業的な酸化プロセスにおいて不可欠である.
研究 の 目的:
- テトラアミドマクロサイクリックリガンド (TAML) を含む鉄 (V) -オクソ複合体に対する陽子の効果を調査する.
- 陽子化された鉄 (V) -オクソ TAML複合体とその結合定数を特徴付ける.
- 酸素原子移転 (OAT) と電子移転 (ET) の反応性に対する陽子化の影響を評価する.
主な方法:
- 単核非ヘムFe(V) -オクソTAML複合体 (1) およびその陽子化された形態 (2および3) の合成と特徴づけ
- DFT計算による共鳴ラマン,EXAFS,EPRを含むスペクトロスコーピテクニック.
- 陽子の結合定数と1電子の還元電位 (Ered) の決定.
主要な成果:
- プロトネーションはTAMLリガンドで発生し,明確に定義された鉄 (V) -オクソ種 (2と3) を形成する.
- チオアニゾール誘導体の硫化で顕著な速度の増加 (107倍まで) が観察された.
- 陽子複合体の減少ポテンシャルにおける有意な正のシフト (Ered of 2 = 0.97 V vs 0.33 V for 1)
結論:
- 鉄 ((V) -オクソTAML複合体のプロトネーションは,OATおよびET反応におけるそれらの反応性を著しく高めます.
- 硫化化のメカニズムは,駆動力に応じて,ETまたは直接OATを含むことができます.
- この研究は,高価金属オクソ種の酸調節反応性に関する基本的な洞察を提供します.
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