Replacement of CO ligands by the isolobal gallium(I) compound GaR [R = C(SiMe3)(3)], formation of the transition metal gallium compounds Mn-2(CO)(8)(mu-GaR)(2) and Fe-3(CO)(9)(mu-CO)(mu-GaR)(2)

The tetrahedral alkylgallium(I) compound Ga4R4 1 [R = C(SiMe3)(3)] dissociates in solution with the formationation of the monomeric fragments GaR, which are isolobal to carbon monoxide and are able to replace CO ligands in transition metal carbonyl complexes. By the substitution of two CO groups, the treatment of Mn-2(CO)(10) and Fe-3(CO)(12) with 1 yielded the two novel transition metal gallium complexes Mn-2(CO)(8)(mu-GaR)(2) 2 and Fe-3(CO)(9)(mu-CO)(mu-GaR)(2) 3, neither of which is isostructural to the starting carbonyl compounds. The GaR ligands bridge both manganese atoms of 2 with all carbonyl groups in terminal positions, and two edges of the central Fe-3 triangle of 3 are occupied by GaR, while the third one is bridged by carbon monoxide.