Ni(dppe) Cl(2) -触媒連鎖成長ポリメリゼーションに関するメカニズム研究:速度決定的還元性除去のための証拠
1Department of Chemistry and Macromolecular Science and Engineering Program, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109-1055, USA.
Journal of the American Chemical Society
|October 29, 2009
まとめ
この研究では,ニッケル触媒による連鎖成長ポリメリゼーション機構を調査した. リデュークティブ・エリメーションは,アリルおよびチオフェン単体の両方の速度を決定するステップとして特定され,LiClは影響を示さなかった.
科学分野:
- 有機金属化学 有機金属化学
- ポリマーサイエンスの科学
- カタリシス カタリシス カタリシス
背景:
- ニッケル触媒によるクロスカップリング反応は,ポリマー合成において不可欠である.
- 聚合化のメカニズムの理解は,ポリマーの性質を制御するために不可欠です.
研究 の 目的:
- 特定のアリルおよびチオフェンモノメアの連鎖成長ポリメリゼーションメカニズムを解明する.
- 速度を決定するステップと,触媒とモノマー濃度の役割を特定する.
主な方法:
- 速度の研究のために,インシットIRスペクトロスコーピーとガスクロマトグラフィーを利用しました.
- 反応性有機金属中間物質を特徴付けるために使用された (31) P NMRスペクトロスコーピー.
- ポリメリゼーション運動に対するLiCl添加物の効果を調査した.
主要な成果:
- 両方のポリメリゼーションは,触媒濃度に対する1次元の依存性と,モノマー濃度に対する0次元の依存性を示した.
- 不対称なNi (II) -バイリルおよびNi (II) -ビチオフェン複合体を静止状態として特定した.
- 還元性排除は,両方のモノマーの割合決定のステップであると決定されました.
結論:
- この発見は,Ni ((dppe) Cl (((2) -触媒化された鎖成長ポリメリゼーションのメカニズム的な洞察を提供します.
- 還元性除去は,ポリメリゼーション率を制御する重要なステップです.
- LiClは速度決定のステップや分子量分布に影響を与えない.
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