Sc3+で誘発されたオキシ鉄 (O2) とその非ヘム鉄 (non-heme iron) の前駆体 (precursor) (II) から Sc3+-ペロキソ-Fe3+の中間体経由で形成される
Feifei Li1, Katherine M Van Heuvelen, Katlyn K Meier
1Department of Chemistry and Center for Metals in Biocatalysis, University of Minnesota, Minneapolis, Minnesota 55455, United States.
Journal of the American Chemical Society
|June 28, 2013
まとめ
レドックス無活性スカンジウム (III) は,鉄の中心部で酸素を活性化し,オキシ鉄 (IV) 複合体を形成します. スカンジウム (III) ペロキシ鉄 (III) の中間物質は,O-O結合の分裂を促進し,非ヘム鉄の触媒化に不可欠である.
科学分野:
- バイオ・オーガニック化学 バイオ・オーガニック化学
- 有機金属化学 有機金属化学
- カタリシス カタリシス カタリシス
背景:
- 非ヘム鉄酵素は,生物学的酸化反応において重要な役割を果たします.
- O2の活性化メカニズムを理解することは,合成触媒の開発の鍵です.
- ルイス酸は,金属中心の反応性に影響することが知られている.
研究 の 目的:
- Fe (II) 複合体によるO2活性化におけるルイス酸,Sc (((3+) の役割を調査する.
- O2活性化経路における潜在的な中間物質をモデル化し,特徴づけること.
- Sc(3+) によって促進されるO−O結合割れのメカニズムを解明する.
主な方法:
- 鉄複合体としてのFe (II) (テトラメチルサイクラム) [Fe (II) (TMC) ]を活用した.
- O2活性化を誘発するために,ルイス酸としてSc(3+) を使用します.
- 代替ルートを用いて[Fe (III) (η (II) -O2 (TMC)) ] (+) のSc3+) アドクトを生成し,特徴づけました.
- ペロキソ介質をオキシ鉄 (IV) 複合体に変換することを研究した.
主要な成果:
- レドックス無活性Sc3+) はFe (II) (TMC) によってO2の活性化を成功裏に誘発した.
- [Fe3+) - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
- このペロキソ介質は,オキシアイロン (IV) コンプレックスに変換することが示されました.
- BPh4の存在は反応を電子ドナーとして促進した.
結論:
- Sc(3+) はルイス酸として作用し,O2の活性化とO−O結合の分裂を促す.
- 特徴づけられたSc(3+) ペロキシ鉄(III) 複合体は,この過程において活性の高い中間体として機能する.
- これらの発見は,生物無機化学に関連する酸素活性化の触媒機構の洞察を提供します.
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