Can SiO bonds be stabilized by Rh/Ir complexes?: A density functional theory study

In an attempt to design a transition-metal complex capable of stabilizing an SiO bond, the interaction of various Rh/Ir complexes with silanones was investigated using the B3LYP density functional method and relativistic effective core potentials. Ir complexes are systematically more strongly bound than their Rh counterparts. Contrary to Pd/Pt complexes, phosphine chelate ligands do not improve bonding, while a strong trans effect exists. Ir(trans-(PH3)2)Cl((CF3)2SiO) is calculated to exhibit strong three-center M–Si–O binding, while a CO ligand trans to the oxygen leads to an almost linear two-center M–SiO binding, which is calculated to be strongest in Ir(trans-(PH3)2)(CO)(iPr2SiO).