σ‑SiH Complexes of Copper: Experimental Evidence and Computational Analysis

Copper and gold complexes 2–4 of
the diphosphine-hydrosilane [Ph2P­(o-C6H4)]2MeSiH ligand 1 have
been prepared, and their bonding situation has been analyzed experimentally
(NMR, IR, X-ray diffraction) and computationally (geometry optimizations,
NBO analyses). The σ-SiH bond remains pendant in the gold complex 4 but engages into a weak side-on coordination to copper.
This bonding interaction slightly strengthens when the metal becomes
more electron deficient, consistent with essentially pure σ-SiH-to-copper
donation. Complexes 2 and 3 provide very
rare examples of σ-bond coordination to a coinage metal.

我们合成了二膦基氢硅烷（diphosphine-hydrosilane）配体1 [Ph₂P(o-C₆H₄)]₂MeSiH的铜与金配合物2~4，并通过实验手段（核磁共振波谱法（NMR）、红外光谱法（IR）、X射线衍射法（X-ray diffraction））与计算方法（几何优化（geometry optimizations）、自然键轨道分析（NBO analyses））对其成键特征进行了系统分析。σ-SiH键在金配合物4中仍保持悬垂状态，而在铜配合物中则可与铜中心形成弱的侧面向配位相互作用。当金属中心电子缺陷程度升高时，该成键相互作用略有增强，这与σ-SiH键向铜中心的纯σ型给电子配位作用基本一致。配合物2与3是极为罕见的σ键配位结合币金属（coinage metal）的案例。