1015757-82-0Relevant articles and documents
Crystal Structures of Cobalt Sandwich Complexes in the η 5-Cyclopentadienyl/η 4-Cyclobutadiene and η 5-Cyclopentadienyl/η 4-Cyclopentadienone Families
Lynch, Daniel E.,Harcourt, Emily M.,Engle, James T.,Farrell, Joshua R.,Ziegler, Christopher J.,Hamilton, Darren G.
, p. 338 - 347 (2020)
Abstract: The crystal structures of six cobalt sandwich complexes—four in the η5-cyclopentadienyl/η4-cyclobutadiene family, two from the related η5-cyclopentadienyl/η4-cyclopentadienone family—are presented and discussed alongside related structural precedents. In each of the complexes an undecorated cyclopentadienyl ligand is present whereas the partner cyclobutadiene or cyclopentadienone ligand bears four identical aromatic substituents (phenyl, p-tolyl, p-fluorophenyl, 2-thienyl or 2,2′-bithienyl). This range of substituents allows for detailed structural comparison between members of the families of sandwich complexes presented here, and with previously reported structures. Graphic Abstract: Crystal structures of members of the η5-cyclopentadienyl/η4-tetraarylcyclobutadiene (left) and η5-cyclopentadienyl/η5-cyclopentadienone (right) families of sandwich complexes are presented.[Figure not available: see fulltext.]
Microwave-assisted synthesis of cyclopentadienyl-cobalt sandwich complexes from diaryl acetylenes
Harcourt, Emily M.,Yonis, Shifra R.,Lynch, Daniel E.,Hamilton, Darren G.
, p. 1653 - 1656 (2009/02/01)
Sealed tube microwave dielectric heating of diaryl acetylenes with cyclopentadienyl cobalt dicarbonyl at elevated temperature in p-xylene provides access to metallocenes in both the cyclobutadiene (Ar4C 4CoCp) and cyclopentadienone (Ar4C4(C=O)CoCp) families. When compared with the traditional thermal approach, the current method offers dramatically reduced reaction times and, especially with respect to cyclopentadienone complexes, increased yields. In the case of an especially bulky diarylacetylene the microwave approach allows access to a complex that cannot be readily obtained under traditional thermal conditions. An initial microwave-promoted Sonogashira coupling may be employed for in situ generation of the diarylacetylene, although lower yields of the metallocene complexes are ultimately obtained.
