Two lithium compounds of the substituted fluorenyl ligand 9-[2-(dimeth
ylamino)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 eta(5) to th
e fluorenyl anion while 3 exhibits an eta(2) arrangement. Structural d
etails have been analyzed to provide additional insights regarding the
nature of the lithium-pi interactions in organolithium compounds with
delocalized pi-systems.