Crystal and molecular structure of trans-di-µ-carbonyl-bis-(π-2,3-cis-dimethylbutadiene carbonylcobalt)

Abstract

The crystal structure of [Co(π-CH₂·CMe·CMe·CH₂)(CO)₂]₂ has been determined by X-ray diffraction methods using counter data. Refinement, to R 0·041, was carried out by a full-matrix least-square procedure. The monoclinic unit cell, space group C2/c, has dimensions a= 16·163, b= 8·744, c= 12·259 Å, β= 105° 40′ for Z= 4. The molecule is centrosymmetric (a requirement of this space group) with a planar Co(CO)₂ Co bridging system. The Co–Co distance is 2·549 Å. The butadiene is in the cis-configuration and is planar. The C–C distances of the butadiene ligand are equal, the mean 1·417 Å.