Synthesis and characterisation of Fe,Co-mixed metal polynuclear complexes with C4H and C4 ligands derived from butadiynyl (X = H) and butadiynediyl iron complexes (X = Fp*), Fp*-CC-CC-X [Fp* = (η5-C5Me5)Fe(CO)2]:: Transformation of the C4(H) cluster frameworks via valence isomerization and 1,2-H shift of the carbon linkages

Sequential addition of Co-2(CO)(8) and Fe-2(CO)(9) to Fp*-C equivalent to C-C equivalent to C-X (X = H (1), Fp* (2)) affords a variety of Fe,Co mixed metal cluster compounds resulting from a combination of (1) addition of a Co-2 fragment to the C equivalent to C bonds, (2) reorganization of the cluster framework including metal-metal bond formation, (3) replacement of metal fragments and transfer of metal fragments, (4) valence isomerization of the C-4(H) Linkage, and (5) 1,2-H shift of the C4H ligand.