Crystal and Molecular Structure of (π-C5H5)Fe3(CO)7C2C6H5 Obtained from (π-C5H5)Fe(CO)2C≡CC6H5 with Fe2(CO)9

Abstract

Abstract The crystal structure of π-C5H5Fe3(CO)2(C2C6H5) obtained from the reaction of π-C5H5Fe(CO)2C2C6H5 with Fe2(CO)9 has been determined from single crystal X-ray diffraction data. The space group is P\bar1 and the cell constants are a=12.635, b=9.457, c=9.033 Å, α=94.64, β=109.10, and γ=99.60°, and Z=2. The refinement was carried out using block-diagonal least-squares calculation including anisotropic thermal factors for the nonhydrogen atoms and isotropic thermal factors for the hydrogens. The final R value for 2488 reflections is 0.035. The molecular configuration consists of an isosceles triangle of the three iron atoms, each two of which bonds to three terminal carbonyl groups and one bonds to the cyclopentadienyl ring. The phenylethynyl group is disposed above the iron plane and is σ-bonded to one iron atom with three carbonyls and α-bonded symmetrically to the other two iron atoms. The seventh carbonyl group is bridged asymmetrically between these two iron atoms, below the iron plane. The characteristic shortening in the Fe–C σ-bond and in the acetylenic C–C bond was observed.