Dinuclear Iridium Complexes Containing Cp* and Carbonyl Ligands: Synthesis, Structure, and Reactivity

The syntheses of the monomeric cationic complexes (Cp*(CO)Ir(R)(CH2Cl2)] were attempted (Cp* = eta(5)-C5Me5, R = Me, H). The target complexes were not obtained; instead, dimeric products were isolated in high yields. The reaction between Cp*(CO)Ir(Me)Cl and [Li(Et2O)(2.5)][BAr4F] afforded the cationic complex [{Cp*(CO)Ir(Me)}(2)(mu-Cl)][BAr4F] (4) in high yield. Complex 4 has been characterized by H-1 NMR, C-13{H-1} NMR, and IR spectroscopies. Reaction of Cp*(CO)Ir(H)(2) with [CPh3][BAr4F] produced the dicationic complex [Cp*(CO)Ir(mu-H)](2)[BAr4F](2) (9) in excellent yield. Complex 9 has been characterized by H-1 NMR and IR spectroscopies as well as elemental analysis and single-crystal X-ray diffraction. An X-ray structural determination was also carried out on the related complex [Cp*(Cl)Ir(mu-H)](2) (14). The solid-state structures of 9 and 14 are compared briefly.