Dehydrogenative Double C−H Bond Activation in a Germylene‐Rhodium Complex **

Transition metal tetrylene complexes offer great opportunities for molecular cooperation due to the ambiphilic character of the group 14 element. Here we focus on the coordination of germylene [(Ar Mes2 ) 2 Ge :] (Ar Mes =C 6 H 3 ‐2,6‐(C 6 H 2 ‐2,4,6‐Me 3 ) 2 ) to [RhCl(COD)] 2 (COD=1,5‐cyclooctadiene), which yields a neutral germyl complex in which the rhodium center exhibits both η 6 ‐ and η 2 ‐coordination to two mesityl rings in an unusual pincer‐type structure. Chloride abstraction from this species triggers a singular dehydrogenative double C−H bond activation across the Ge/Rh motif. We have isolated and fully characterized three rhodium‐germyl species associated to three C−H cleavage events along this process. The reaction mechanism has been further investigated by computational means, supporting the key cooperative action of rhodium and germanium centers.