New ionic fluorenylnickel complexes: Synthesis and solid state structure

New fluorenylnickel complexes [M(THF)n]+[Ni(η5-Flu)(η1-Flu)2]− (M = +48 Li, 1 and M = Na, 2) have been obtained in the reaction of nickel bromide with fluorenyllithium and -sodium. The X-ray molecular structures of 1 (monoclinic; P21/c) and 2 (orthorhombic; Fdd2) reveal that in both complexes two fluorenyl ligands are bonded to the nickel atom by η1 bond and the third one is bonded to the nickel atom by η5 bond. Complexes 1 and 2 are the first structurally characterized nickel complexes bearing fluorenyl ligands.