The structures of Ir II compounds could be authenticated by X-ray diffraction studies (Figure and S10-13) after growing crystals by slow diffusion of pentane into their toluene solutions. The Ir-P bond distances of all Ir II complexes are elongated (1•BAr F 2.313 and and and and and and.2913( )) in comparison to those in the Ir I precursor 1 and and and.2793( )) ( ), which may be attributed to electrostatic and Pauli repulsion effects. At the same time the Ir-Cipso distances in complexes 1•BAr F (1.979( )), 2•BAr F (2.026( )) and and), attributed to the stronger σ-donation to the more electrophilic Ir II . ( ) The shorter C-C distance exhibited by the coordinated ethylene in complex 2•BAr F (1.248( )) versus 2 (1.390( )) reflects the lesser extent of backdonation ability of the oxidized metal center.