一个不寻常的Y形三坐标Pt复合物的理论研究:Pt(0) σ-迪西兰复合物或Pt(II) 迪西复合物?
Nozomi Takagi1, Shigeyoshi Sakaki
1Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-Nishihiraki-cho 43-4, Sakyo-ku, Kyoto 606-8103, Japan.
Journal of the American Chemical Society
|June 12, 2012
概括
具有不寻常Y形的复合物很可能是(0) 迪西兰,而不是(II). 这一发现为和其他债券的减少性消除快照提供了洞察力.
科学领域:
- 有机金属化学 有机金属化学
- 计算化学计算化学
- 材料科学 材料科学 材料科学
背景情况:
- 一个三坐标复合物的Y形结构,Pt[NHC(Dip) ((2)) ](SiMe ((2)) Ph) ((2),最初被提出作为迪西兰还原性消除的快照.
- 该复杂的特征是N-异环碳 (NHC) 和西联体,Dip代表2,6-二二烯.
研究的目的:
- 为了研究不寻常的Y形白金复合体中的电子结构和粘合.
- 要确定该复合体是否代表一个Pt(II) disilyl物种或一个Pt(0) disilane物种.
- 探索涉及和其他元素-元素键的还原性消除过程的更广泛影响.
主要方法:
- 用密度函数理论 (DFT) 的计算来研究电子结构和结合.
- (195) Pt NMR光谱法用于分析中心的化学转移.
- 对Si-Si结合相互作用和与中心的分子轨道相互作用的分析.
主要成果:
- DFT的计算表明,Y形结构源于基和基连接体的强烈转变影响.
- 这种 (195) Pt NMR 化学转移对 Pt(0) 复合体比 Pt(II) 复合体更具特征.
- Si-Si 结合相互作用明显低于典型的 Si-Si 单键,表明电荷转移到中心.
- 对于其他具有强度捐赠连接体的金属复合物以及对Ge-Ge,B-B和B-Si键的减少性消除,观察或预测了类似的Y形结构.
结论:
- 研究的复合物最好描述为一个Pt(0) σ-disilane复合物,它代表了显著电荷转移后的快照.
- 这些发现为减少性消除反应的机制提供了新的视角.
- 这项研究表明,在各种元素-元素 σ 键的还原性消除中可以观察到类似的 Y 形结构.
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