Synthesis and crystal structure of (Et4N)[{μ 3-SbI}Fe3(η 5-C5H5)(CO)10]

Crystal structure of (Et₄N)[{μ ₃-SbI}Fe₃-SbI}Fe₃Cp(CO)₁₀] was determined by X-ray diffraction analysis. The compound was synthesized by the reaction between (Et₄N)₂[Fe₂(CO)₈] and CpFe(CO)₂SbI₂ in a THF solution with cooling in an argon atmosphere. The crystals are monoclinic, a=12.792(2), b=14.152(3), c=17.373(3) Å, β=92.32(1)°, V_cell=3143(1) ų, space group P2₁/n, Z=4, d_calc=1.885 g/cm³, Syntex P2₁, λCuK_α radiation, R(F)=0.0744 for 877 F_hkl>6σ(F_hkl). The data were corrected for crystal decomposition according to the drop in the intensities of control reflections (by 23% during 29 h X-ray exposure). In the cluster anion, the Sb?Fe distances (ave. 2.57(1) Å) and the I?Sb?Fe and Fe?Sb?Fe angles (ave. 102.7(6) and 115.4(4)°) have virtually the same values as in other known complexes containing HalSbFe₃ and SbFe₄ fragments. The Fe...Fe distances of 4.312-4.369 Å indicate that the metal-metal bonds are absent.