The First Trimetallic Pd/Tl/Co Carbonyl Cluster, Trigonal [Pd 9 {μ 3 ‐TlCo(CO) 3 L}(μ 2 ‐CO) 6 (μ 3 ‐CO) 3 L 6 ]: Ligand‐Stabilization of the Trigonal‐Bipyramidal [TlCo(CO) 3 L] Entity

Easy come, easy go : The reaction of [Pd 4 (CO) 5 L 4 ] and/or [Pd 10 (CO) 12 L 6 ] (L=PEt 3 ) with [TlCo(CO) 4 ] gives the title compound (see structure, CO and ethyl groups removed), in which the [TlCo(CO) 4 ] reactant serves as a ligand (in its monosubstituted [TlCo(CO) 3 L] form). Temperature‐dependent NMR spectroscopy indicates dynamic behavior involving the rapid reversible dissociation/association of the entire [TlCo(CO) 3 L] ligand.