The Complex Ions [C 5 H 5 M(CO) 3 ] ⊖ (MMo, W) as 6e‐Ligands: Synthesis and Molecular Structure of [(η 4 ‐C 4 Me 4 )‐Co(μ‐CO) 3 M(η 5 )] (MMo, W)

A model example for the isolobal analogy between the 6e‐donor [(C 5 H 5 )M(CO) 3 ] ⊖ and C 5 H   5 ⊖(see previous communication) is the title compund 2 . It is formed upon thermal elimination of CO from 1 . The symmetric coordination of the (C 5 H 5 )W(CO) 3 fragment has been confirmed by X‐ray structure analysis.