Crystal and molecular structure of di-µ-carbonyl-(tricarbonylcobaltio)carbonyl(π-cyclopentadienyl)iron

Abstract

The crystal structure of the title compound has been determined by X-ray diffraction methods by use of counter data and refined to R 0·055 for 1240 unique reflections by a full-matrix least-squares procedure. The monoclinic unit cell, space group P2₁/m, has dimensions. a= 7·008 ± 0·009, b= 10·941 ± 0·107, c= 8·605 ± 0·016 Å, β= 104·7 ± 0·1°, for Z= 2. The molecule possesses m symmetry (a requirement of the space group) and has a non-planar Fe(CO)₂Co bridging system, the angle between the two Fe(CO)Co planes being 143·5°. Fe ⋯ Co is 2·545(1)Å. The terminal carbonyl groups lying on the mirror plane are in a cis-configuration. The metal to bridge-carbon distances are: Fe–C 1·882(7), Co–C 2·036(7)Å. The cobalt is in a square-based pyramidal environment.