A Crystalline σ Complex of Copper

Over the last decades, our understanding of σ-bond activation at transition metals has progressed considerably from both fundamental and synthetic points of view thanks to the preparation and characterization of a variety of σ complexes. Here we report the synthesis and structural analysis of the first σ complex involving a coinage metal. The copper(I) complex 2 derived from the diphosphine−disilane [Ph2P(C6H4)Me2Si−SiMe2(C6H4)PPh2] (1) has been isolated and crystallographically characterized. The coordination of the Si−Si σ bond to copper was thoroughly analyzed by quantum-chemical methods.