Manganese complexes of the pentaphenylcyclopentadienyl ligand

The complexes, [Mn(C5Ar5)(CO)2L] (Ar = Ph, p-tol; L = CO, PMe2Ph), of the bulky cylopentadienyl ligands, pentaphenylcyclopentadienyl and penta(p-tolyl)cyclopentadienyl have been prepared and characterised. The crystal structures of two derivatives are reported. The reversible cyclic voltammetric oxidations of the compounds [Mn(C5Ar5)(CO)3] indicate that the p-tolyl substituents confer thermodynamic stability on higher oxidation state complexes of these ligands.