Structural Studies of {9-[2-(Dimethylamino)ethyl]fluorenyl}lithium Compounds

Two lithium compounds of the substituted fluorenyl ligand 9-[2-(dimethylamino)ethyl]fluorenyl (Fl N ) have been prepared and isolated. The X-ray crystal structures of Fl N Li·Et 2 O (2) and Fl N Li·2THF (3) have been obtained. In 2 the lithium atom is coordinated η 5 to the fluorenyl anion while 3 exhibits an η 2 arrangement. Structural details have been analyzed to provide additional insights regarding the nature of the lithium-π interactions in organolithium compounds with delocalized π-systems.