The solution and solid state structure of {[1-(dimethylamino)-8-naphthyl]lithium center dot THF}(2)

The reaction of N,N-dimethyl-1-naphthylamine with butyllithium agents is kn own to yield the peri lithiated product (3). The now reported structure of dimeric [1-(dimethylamino)-8-naphthyl]lithium with two molecules of THF (3 . THF)(2) shows a twist angle between the naphthyl-rings and the Li-C-ipso- Li plane of ca. 38 degrees. The magnitude of the (1)J(C-13,Li-7) coupling c onstant as well as the line splitting pattern of the lithiated carbon atom in the C-13 spectrum (THF-d(8)) demonstrate the existence of a dimeric spec ies at -90 degreesC in solution. A previously published single crystal X-ra y structure of dimeric [1-(dimethylamino)-8-naphthyl]lithium with two coord inating molecules of diethyl ether (3 . Et2O)(2) shows a smaller twist angl e between the naphthyl-rings and the Li-C-ipso-Li plane of ca. 11 degrees. We assign this reduction of the twist angle to the weaker solvation propert ies of Et2O.