A recent article by the Murahashi group describes a novel complex of a palladium cluster sandwiched...
A recent article by the Murahashi group describes a novel complex of a palladium cluster sandwiched by two arenes (Y. Ishikawa et al,Angew. Chem. Int. Ed. 2015, 54. DOI: 10.1002/anie.201409499). After several attempts using benzene and 1,3,5-cydoheptatriene, the synthesis of the cluster was achieved with the use of cyclooctatetraene (COT, see below). Explain why COT was not their first choice but why it was ultimately better suited to bind a Pd} cluster than benzene. DFT calculations suggested that there are two degenerate Pdf orbitals, shown below, that contribute to degenerate HOMO interactions with benzene and COT. Draw the benzene and COT it orbitals that match the Pd} orbitals shown below. What is the oxidation state of each Pd in the Pd cluster complex? Explain.