中間コバルト (IV) ニトリド複合体とそのN-移動性挿入産物
Eva M Zolnhofer1, Martina Käß, Marat M Khusniyarov
1Department of Chemistry and Pharmacy, Inorganic Chemistry, Friedrich-Alexander University Erlangen - Nürnberg (FAU) , Egerlandstr. 1, 91058 Erlangen, Germany.
Journal of the American Chemical Society
|September 23, 2014
まとめ
低温実験では,アジド複合体から形成された非常に反応性の高いコバルト (IV) ニトリド種が明らかになりました. この一時的なニトリドはN-移住的挿入を経て,希少な,キラル,トライゴナルピラミダルコバルト (III) 複合体を生成します.
科学分野:
- 無機化学 無機化学とは
- 有機金属化学 有機金属化学
- スペクトロスコーピーは,スペクトロスコーピーを用います.
背景:
- 低コーディネート,高価金属ニトリド種の反応性を調査することは,窒素移転メカニズムを理解するために重要である.
- アジド複合体は,反応性ニトリド中間産物の生成の前駆体として機能する.
- 金属中心の電子構成とスピン状態は,その反応性と安定性を決定する.
研究 の 目的:
- 高価なコバルトニトリドの種を合成し,特徴づけること.
- コバルトニトリド中間物の反応経路を解明する.
- 結果となるN-移動性挿入製品とそのユニークな構造的特徴を特徴づける.
主な方法:
- アジドコバルト複合体の低温 (10 K) 光分解.
- 中間モニタリングのための電子パラマグネット共振 (EPR) スペクトロスコーピー.
- 電子構造と反応経路に関する密度関数理論 (DFT) 計算.
- CHN元素分析,NMR,IR,UV-vis,SQUID磁気測定,X線結晶学を用いた製品の包括的な特徴付け.
主要な成果:
- アジド前駆体 (1) から,低温で高反応性,高価コバルト (IV) ニトリド種 (2) を形成する.
- DFTの計算は,コバルト (IV) 窒化物の低スピン d ((5),S=1/2の構成をサポートしています.
- N-移動性挿入産物,トライゴナルピラミダルコバルト (III) 複合体 (3) の分離と特徴づけ
- ニトリド (2) から製品 (3) への反応経路は,低活性化バリア (2.2 kcal mol ((-1)) を有する容易なN-移動挿入を経由して進みます.
結論:
- この研究は,一時的で高価なコバルト (IV) ニトリドの生成と特徴づけを証明しています.
- コバルト (IV) ニトリドは,Co-C結合に容易なN-移動性挿入を経験する.
- その結果生じるコバルト (II) 複合体 (3) は,異なったドナーリガンドを持つキラル,トライゴナルピラミッド複合体の珍しい例であり,異常な協調化学を強調しています.
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