Dicobalt hexacarbonyl acetylene complexes are a family of In
organocobalt compounds with the formula . A large variety of R groups are tolerated. They are red compounds that are soluble in organic solvents. They arise from the reaction of alkynes and
dicobalt octacarbonyl:
:
According to
X-ray crystallography
X-ray crystallography is the experimental science of determining the atomic and molecular structure of a crystal, in which the crystalline structure causes a beam of incident X-rays to Diffraction, diffract in specific directions. By measuring th ...
, the two Co atoms and two alkyne carbons form the vertices of a distorted tetrahedron. The C-C distance for the bridging
alkyne ligand is 1.33 Å, and the Co-Co distance is 2.47 Å. The core has C
2v symmetry
Symmetry () in everyday life refers to a sense of harmonious and beautiful proportion and balance. In mathematics, the term has a more precise definition and is usually used to refer to an object that is Invariant (mathematics), invariant und ...
.
[{{cite journal , doi=10.1021/om00161a029, title=Diastereoselective Ligand and Vertex Substitutions in Bimetallic Bridged Alkyne Clusters: X-Ray Crystal Structure of .mu.2-(endo-2-Propynylborneol)hexacarbonyldicobalt , year=1990 , last1=d'Agostino , first1=Michael F. , last2=Frampton , first2=Christopher S. , last3=McGlinchey , first3=Michael J. , journal=Organometallics , volume=9 , issue=11 , pages=2972–2984 ] The structure is related to that of
methylidynetricobaltnonacarbonyl
Methylidynetricobaltnonacarbonyl is an Organometallic chemistry, organometallic cobalt cluster with the chemical formula Co3(CO)9CH that contains a metal carbonyl core with the Methylidyne group, methylidyne ligand, first discovered in the late 195 ...
and
tetracobalt dodecacarbonyl, which are also
tetrahedrane
Tetrahedrane is a hypothetical platonic hydrocarbon with chemical formula and a tetrahedral structure. The molecule would be subject to considerable angle strain and has not been synthesized . However, a number of derivatives have been prepa ...
s.
These complexes are intermediates in the
Pauson-Khand reaction.
References
Cobalt carbonyl complexes