Metal–metal bonding in co-ordination complexes. Part XI. Crystal and molecular structure of di[(benzenesulphinato)-µ-hydroxo-phenylstannio]-tetracarbonyldi-π-cyclopentadienyl-di-iron

The compound previously formulated as (π-C5H5)Fe(CO)2Sn(Ph)(OSOPh)(OH) has been shown, by X-ray analysis, to be a centrosymmetric dimer with two five-co-ordinate tin atoms linked by a dihydroxo-bridge. The Sn–O bond lengths are 2·054(2)A and the O–Sn–O and Sn–O–Sn bond angles are 70·8(1) and 109·2(1)°, respectively. The Sn–Fe bond distance of 2·499(1)A is ca. 0·03 A longer than the limiting value for this bond type and is presumed to be a σ-bond. Other bond distances of interest are Sn–O(non-bridging) 2·206(2), Sn–C 2·146(3), Fe–C(carbonyl) 1·765(4), Fe–C(ring) 2·093(4), CO 1·142(5), S–O 1·539(3), SO 1·499(3), and S–C 1·808(4)A.Crystals of the dimer are monoclinic with cell dimensions a= 9·698(2)b= 18·097(3), c= 13·516(4)A, β= 123·44(3)°, space group P21/c, and Z= 2. The structure analysis, based on 2592 independent intensities measured by counter diffractometry, was carried out by the heavy-atom method and refinement was by least-squares techniques to a final R of 0·024.