Chemistry of Iridium Carbonyl Cluster Complexes. Synthesis and X-ray Crystal Structure Determination of the [NMe3(CH2Ph)]3[Ir9(μ-CO)7(CO)13] Complex Containing a Cofacial Bioctahedral Iridium Cluster. Another Example of Different Electron Counting between Isoskeletal Rhodium and Iridium Carbonyl Clusters