Synthesis and Reactivity of Rhodium(I) and Iridium(I) Chloride Complexes of a Trisphosphinine

The SiMe 2 linked tris(phosphinine) 1 reacts with [M(COD)Cl] 2 (M = Rh, Ir) to give the corresponding [M( 1 )Cl] complexes 2 and 3 . The X-ray crystal structure of 2 reveals a highly twisted geometry of 1 around the rhodium center. Abstraction of the chloride ligand with AgOtf in the presence of CH 3 CN yields the corresponding cationic complexes 4 and 5 . The CH 3 CN ligand can be quantitatively displaced from 4 by CO to form a cationic carbonyl complex 6 in which the Rh center is highly Lewis acidic. It was also shown that, upon reaction with HCl, 3 equilibrates with the [Ir( 1 )HCl 2 ] complex 7 .