STRUCTURE AND BONDING OF FE4(CO)10(MU-CO)(MU-4-S)2 CLUSTER SYNTHESIS .23. THE SYNTHESIS

The compound Fe4(CO)10(-CO)(4-S)2 (1) was synthesized in 38% yield by the UV induced decarbonylation of Fe(CO)5 in the presence of Fe3(CO)9(3-S)2. Compound 1 was characterized by a single-crystal X-ray diffraction analysis. Space group: Pccn, a = 6.603(1), b = 15.429(3), c = 17.292(4) , Z = 4. The structure was solved by direct methods and was refined (807 reflections) to the final values of the residuals R = 0.043 and Rw = 0.054. The molecule consists of a planar array of four iron atoms with a quadruply bridging sulphido ligand on each side of the plane. The shortest metal-metal bond, 2.489(3) , contains a bridging carbonyl ligand. Semi-bridging carbonyl ligands bridge the two adjacent metal-metal bonds, 2.532(2) . The longest metal-metal bond, 2.605(2) , has no carbonyl bridge. Compound 1 is unsaturated (by EAN rule) by the amount of two electrons. The two semi-bridged carbonyl-metal bonds in 1 are significantly shorter than those in the saturated cluster Fe2CO2(CO)11(4-S)2. A molecular orbital description which explains the differences in bonding between the two compounds is proposed. 1989.

CLUSTER SYNTHESIS .23. THE SYNTHESIS, STRUCTURE AND BONDING OF FE4(CO)10(MU-CO)(MU-4-S)2 Academic Article