Three‐Coordinate Rhodium Complexes in Low Oxidation States

The isolation of simultaneously low‐coordinate and low‐valent compounds is a timeless challenge for preparative chemists. This work showcases the preparation and full characterization of tri‐coordinate rhodium(‐I) and rhodium(0) complexes as well as a rare rhodium(I) complex. Reduction of [{Rh(μ‐Cl)(IPr)(dvtms)} 2 ] ( 1 , IPr=1,3‐bis(2,6‐diisopropylphenyl)imidazolyl‐2‐ylidene; dvtms=divinyltetramethyldisiloxane) with KC 8 gave the trigonal complexes K[Rh(IPr)(dvtms)] and [Rh(IPr)(dvtms)], whereas the cation [Rh(IPr)(dvtms)] + results from their oxidation or by abstraction of chloride from 1 with silver salts. The paramagnetic Rh 0 complex is a unique fully metal‐centered radical with the unpaired electron in the d z2 orbital. The Rh(‐I) complex reacts with PPh 3 with replacement of the NHC ligand, and behaves as a nucleophile, which upon reaction with [AuCl(PPh 3 )] generates the trigonal pyramidal complex [(IPr)(dvtms)Rh‐Au(PPh 3 )] with a metal–metal bond between two d 10 metal centers.