鉄のピンチャー複合体によって触媒化されたアンモニア・ボラン脱水化のメカニズム研究
Papri Bhattacharya1, Jeanette A Krause, Hairong Guan
1Department of Chemistry, University of Cincinnati , P.O. Box 210172, Cincinnati, Ohio 45221-0172, United States.
Journal of the American Chemical Society
|July 19, 2014
まとめ
鉄のピンチャー複合体は,アンモニア・ボランの脱水化を効率的に触媒化し,水素ガスを放出します. 複合体3は,レート決定のステップで同時にB-HとN-Hの債券が割れ,最も高い活性を示しています.
科学分野:
- 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
- 水素貯蔵庫は水素を貯蔵する場所です.
背景:
- アンモニアボラン (AB) は,有望な水素貯蔵材料です.
- ABの効率的な触媒脱水化は,水素の放出に不可欠である.
- 鉄複合体は,貴金属触媒の費用対効果の高い代替品を提供します.
研究 の 目的:
- アンモニア・ボラン脱水化のための新しい鉄ビス ((phosphinite) ピンサー複合体を合成し,評価する.
- これらの鉄複合体の触媒的活動とメカニズムを調査する.
- 最も活発な触媒を特定し,速度を決定するステップを明らかにする.
主な方法:
- 鉄ビス (((フォスフィニット)) ピンサー複合体の合成.
- 60 °Cでのアンモニア・ボランの触媒性脱水化.
- 運動イソトープ効果 (KIE) 測定を含む運動学的研究.
- 機械的調査のための核磁気共振 (NMR) スペクトロスコーピー.
主要な成果:
- 複合体1-3はAB脱水化を触媒化し,24時間以内にABあたり2.3-2.5等価のH2を放出する.
- 鉄複合体3は,最も高い触媒活性を示した.
- 動力学的研究は,触媒3に対する第一次元の依存性と,ABに対するゼロ次元の依存性を明らかにした.
- KIEの分析は,レート決定のステップにおいて,B-HとN-Hの債券の同時分割を示した.
結論:
- 鉄二酸化塩素 (鉄二酸化塩素) ピンチャー複合体は,アンモニア・ボラン脱水化のための効果的な触媒である.
- 複合体3は,研究されたものの中で最も活発な触媒である.
- 触媒メカニズムは,B-HとN-H結合の同時分裂を伴い,鉄の中心に対するABの調整を伴う.
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