The Synthesis and Catalytic Properties of Some Open‐Sided Binuclear Complexes of Rh I : The Structure of [Rh 2 (CO) 2 (CH 3 CN) 2 {CH(PPh 2 ) 3 }](CF 3 SO 3 ) 2

Strong donor‐acceptor character is the salient feature of the RhRh bond in 1 , which contains two coordinatively unsaturated, neighboring Rh1 centers. The “more open” Rh center, coordinated in a square‐pyramidal fashion, thereby becomes so electron poor that CO adds to the square‐planar Rh center upon reaction with 1 (L = MeCN). A complex analogous to 1 catalyzes hydrogenation.