Photoinduced Formal GallyleneTransfer from Gallium-BridgedDimetallic Complexes to 16-Electron Metal Fragments.

Photoirradiation of the mixtures of Cp′(dppe)FeGaM(CO)5(Cp′ = η5-C5Me5(Cp*), M = W (2), Cr (3); Cp′ =η5-C5H5(Cp), M = W (5), Cr (6)) and Fe(CO)5in C6D6caused formal gallylene transfer from 2, 3, 5, and 6to the Fe(CO)4fragmentto afford the gallium-bridged diiron complexes Cp′(dppe)FeGaFe(CO)4(Cp′ = Cp* (1), Cp (4))in moderate yields. Gallylene transfers with Cp(dppe)FeGaFe(CO)4(4) and M(CO)6(M = W, Cr) also tookplace to produce 5and 6, respectively;however, that with Cp*(dppe)FeGaFe(CO)4(1) and M(CO)6did not proceed. Photoirradiation of 4alone in toluene caused CO dissociation and dimerizationto afford the gallylene-bridged tetrametallic complex {μ-Cp(dppe)FeGa}2Fe2(CO)6(μ-CO) (8). In contrast to 4, the Cp* analogue 1gave no gallylene-bridged complex in a similar reaction. [ABSTRACT FROM AUTHOR]