The compound [W(CC₆H₄Me-4)(CO)₂(η-C₅Me₅)](1) reacts with [Fe(CO)₃(η-C₈H₁₄)₂] in hexane at ca.–50 °C to give predominantly the electronically unsaturated dimetal complex [FeW(µ-CC₆H₄Me-4)(CO)₅(η-C₅Me₅)](2). With [Fe₂(CO)₉] in Et₂O at ca. 10 °C, compound (1) yields a chromatographically separable mixture of (2), the saturated dimetal species [FeW(µ-CC₆H₄Me-4)(CO)₆(η-C₅Me₅)], and the trimetal compound [Fe₂W(µ₃-CC₆H₄Me-4)(µ-CO)(CO)₈(η-C₅Me₅)]. The latter is best obtained by treating (1) with excess of [Fe₂(CO)₉] in Et₂O at ambient temperatures. Complex (2) reacts with oxygen and with sulphur to afford [FeW{µ-C(C₆H₄Me-4)C(O)O}(CO)₅(η-C₅Me₅)](5) and [FeW(µ-SCC₆H₄Me-4)(CO)₅(η-C₅Me₅)], respectively. The structure of (5) has been established by X-ray diffraction. The Fe–W bond [2.605(1)Å] is bridged by the C(C₆H₄Me-4)C(O)O fragment [Fe–O 2.007(3), W–O 2.128(3), Fe–C(C₆H₄Me-4) 2.054(4), and W–C(C₆H₄Me-4) 2.171(4)Å], with the CO group interacting weakly if at all with the iron or tungsten centres [Fe ⋯ C(O) 2.380(3) and W ⋯ C(O) 2.609(3)Å]. The iron atom carries three CO groups, and the tungsten two CO groups and the η-C₅Me₅ ligand. Treatment of (2) with an excess of CH₂N₂ gives [FeW{µ-C(C₆H₄Me-4)=CH₂}(µ-CH₂)(CO)₅(η-C₅Me₅)]. However, with one equivalent of CH₂N₂, the major product is [FeW{µ-trans-CHC(H)C₆H₄Me-4}(µ-CO)(CO)₅(η-C₅Me₅)], together with spectroscopically identified [FeW{µ-trans-CHC(H)C₆H₄Me-4}(µ-CH₂)(CO)₅(η-C₅Me₅)]. Compound (1) reacts with [Co₂(CO)₈] to give [Co₂W(µ₃-CC₆H₄Me-4)(CO)₈(η-C₅Me₅)], and with [Ni₂(µ-CO)₂(η-C₅H₅)₂] to give a mixture of [Ni₂W(µ₃-CC₆H₄Me-4)(CO)₂(η-C₅H₅)₂(η-C₅Me₅)] and [NiW₂(µ-CC₆H₄Me-4)₂(CO)₄(η-C₅Me₅)₂].