マグネシウム複合体における古典的対ブリッジアルリルリガンド:溶媒の役割

Stephen C Chmely¹, Christin N Carlson, Timothy P Hanusa

¹Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235-1822, USA.

Journal of the American Chemical Society

|April 23, 2009

まとめ

マグネシウムアリル複合体は,通常シグマ結合で結合する. しかし,配合塩基がなければ,π結合形態はより安定し,カチオン-π相互作用を示す新しい二核マグネシウム複合体によって証明されています.

科学分野:

有機金属化学有機金属化学
コンピューティング・ケミストリー
材料科学材料科学とは

背景:

マグネシウムアリル複合体は一般的にシグマ結合リガンドで合成され,その最も安定した構成であると考えられています.
調整溶剤や塩基がないマグネシウムアリル複合体の電子的および構造的好みは,理解されがちです.

研究の目的:

座標塩基がない場合にマグネシウムアリル複合体の好ましい結合方法を調査する.
パイ結合マグネシウムアリル複合体の安定性を計算および実験的に検証する.

主な方法:

密度関数理論 (DFT) の計算を使用して,異なるマグネシウムアリル結合モードの電子構造と安定性をモデル化しました.
新型,溶解されていない二核マグネシウム複合体, [Mg{C(3) ((SiMe(3)) (((2) H(3) }] (((2) の合成と分離が行われました.

主要な成果:

DFTの計算は,pi結合アリルリガンドは,座標基が存在しない場合,シグマ結合リガンドよりもエネルギー的に優れていることを予測しています.
合成された二核複合体は,ブリッジングアリルリガンドを特徴としており,解離されていない条件下でのpi結合の予測を確認した.
構造は,マグネシウムセンターとアルリルリガンドのPIシステムとの間に有意なカチオン-PI相互作用を明らかにします.

結論:

この研究は,マグネシウムアリル複合体の独占的な好ましいモードとしてのシグマ結合の長年の仮定に異議を唱える.
不溶性マグネシウムアリル複合体は,分子内カチオン-ピ相互作用によって安定化され,オルガンマグネシウムの化学に関する新しい洞察を提供します.

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