Crystal and molecular structure of di-µ-carbonyl-(carbonyl-π-norbornadienecobaltio)carbonyl-π-cyclopentadienyliron

Abstract

The crystal structure of the title compound was determined by X-ray diffraction methods by the heavy-atom method from counter data, and refined by least-squares techniques to R 0·063 for 3936 unique reflections. The monoclinic unit cell, space group P2₁/c, has dimensions a= 18·013 ± 0·027, b= 6·553 ± 0·017, c= 13·031 ± 0·037 Å, β= 103·2 ± 0·1°, for Z= 4. The dimer molecule has the expected non-planar Fe(CO)₂Co bridging system, the angle between the two Fe(CO)Co planes being 160·6°. The two π-bonded ligands are in a cis-configuration and the molecule as a whole has approximately m(C₈) symmetry. The metal to bridge-carbon distances arc equivalent (mean 1·909 Å). The environment of the cobalt is square-based pyramidal, and that of the iron octahedral; Fe ⋯ Co is 2·520(1)Å.