Synthesis of dinuclear alkenyl-bridged iron-nickel and diiron complexes. The crystal structure of [Fe₂(CO)₄(C₅H₅)(μ-CO) (μ-CPhCPhH)]

The reaction of the anions [Fe(η3-R1HCCR2CO)(CO)3] - (R1 H, R2CO2Me and CO2Et; R1 R2 CO2Me) with [Ni(C5H5)(PPh3)Br] gives the complexes [FeNi(CO)3(C5H5)(PPh3)(μ- R2CCH2)] (R2 CO2Me (1) and CO2Et(2)) and [FeNi(CO)2(C5H5)(PPh3)(μ- MeO2CCC(H)CO2Me)] (3). Complexes 1 and 2 have been also obtained by heating mixtures of [PPh4][HFe(CO)4]-, R1CCR2, and [Ni(C5H5)(PPh3)Br] in THF. Use of the [HFe(CO)4]-/PhCCPh/M(C5H5)L xX (M Ni, Lx PPh3 and M Fe, Lx (CO)2) system was successful for the synthesis of [FeNi(CO)3(C5H5)(PPh3)(μ- CPhCCPhH)] (4) and [Fe2(CO)4(C5H5)(μ-CO) (μ-PhCCPhH)] (5) complexes. The structure of 5 was determined by an X-ray diffraction study. © 1990.