Crystal Structures of Cobalt Sandwich Complexes in the η 5-Cyclopentadienyl/η 4-Cyclobutadiene and η 5-Cyclopentadienyl/η 4-Cyclopentadienone Families

Article abstract of DOI:10.1007/s10870-019-00806-4

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.]