Synthesis of an Organolanthanoid Complex with a Novel High-Strain Anionic Cyclohexen-4-yne Ligand and Crystal Structure of ((η5-Cp) 2Sm(η5-C6H5)(thf)).

An organosamarium complex, [(η5-Cp)2Sm(η5-C6H5)(thf)], with a novel high-strain anionic cyclohexen-4-yne ligand, a new benzene isomer, has been synthesised.