O2を持つPd(I) -Pd(I) ダイマーの反応性:平衡状態のモノハプトPd超酸化物と二パラジウム過酸化物の反応性
Rafael Huacuja1, Daniel J Graham, Claudia M Fafard
1Department of Chemistry, Texas A&M University, College Station, Texas 77842, United States.
Journal of the American Chemical Society
|March 1, 2011
まとめ
光で活性化されたパラジウムジメルは,酸素と反応して,パラジウム-超酸化物またはパラジウム-過酸化物複合体を形成します. これらの正方形平面パラジウム (II) 複合体は,酸素と均衡状態にあり,電子密度は超酸化物リガンドに局限しています.
科学分野:
- 有機金属化学 有機金属化学
- フォトケミストリーは,写真化学です.
- 協調化化学について
背景:
- パラジウム複合体は,有機合成における汎用的な触媒である.
- 低価パラジウム種の酸化物質に対する反応性を理解することは極めて重要です.
- 光活性化により,金属複合体の新しい反応経路が可能になる.
研究 の 目的:
- 光照射下で分子酸素とPd(I) -Pd(I) ダイマーの反応を調査する.
- その結果生じるパラジウム-酸素種を特徴づけるために.
- 光生成複合体の電子構造と結合を決定する.
主な方法:
- [((F) PNP) Pd] (((2) ダイメルの合成と特徴づけ
- O(2) との光化学反応である.
- スペクトル分析 (例えば,UV-Vis,EPR) とX線結晶学により,構造と電子特性を決定する.
主要な成果:
- Pd(I) -Pd(I) ダイマーは,光の下でO(2) と反応して,パラジウム-超酸化物とパラジウム-過酸化物種を生成します.
- 両製品とも正方形の平面Pd (II) センターを備えています.
- 結合した酸素種と自由のO2の間には均衡がある.
- スーパーオキシド複合体のペアレス電子密度は,O(2) リガンドに局在しています.
結論:
- Pd(I) ダイマーの光活性化により,反応性のあるパラジウム-酸素中間物質への経路が提供されます.
- 観測された均衡は,調整された酸素と自由な酸素の微妙なバランスを強調しています.
- 超酸化リガンドの電子密度の局所化は,これらの複合体の電子構造の洞察を提供します.
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