STEREOCHEMICAL ANALYSIS OF FE2(CO)6(MU-SE2) - DISELENIUM ANALOG OF FE2(CO)6(MU-S2)

The structure of Fe2(CO)6(μ-Se2) has been determined by X-ray diffraction. The compound is isomorphous with triclinic Fe2(CO)6(μ-S2) and crystallizes with two dimeric molecules in an unit cell of PĪ symmetry and of reduced cell parameters (at -95 ± 5 °C) of a = 7.704 (2) Å, b = 11.779 (6) Å, c = 6.585 (3) Å, α = 104.86 (4)°, β = 102.28 (3)°, and γ = 84.27 (3)°. Three-dimensional anisotropic least-squares refinement of all atoms resulted in final discrepancy factors of R1(F) = 3.6% and R2(F) = 4.4% for 906 observed independent reflections with I> 2σ(I). The Fe2(CO)6(M-Se2) molecule possesses an idealized C2v-2mm geometry with an Fe-Fe bond distance of 2.575 (2) Å, a Se-Se bond distance of 2.293 (2) Å, and an average Fe-Se bond distance of 2.364 Å. © 1979, American Chemical Society. All rights reserved.