Lanthanide complexes of boraamidinate ligands: synthesis and X-ray structures of {[Li(THF)4][bamLnCl2(THF)]}2 (bam = [PhB(NDipp)2](2-); Ln = Y, Pr, Nd, Sm, Ho, Er, Yb) and {bamLnCl(THF)2}2 (Ln = Y, Sm).

The first examples of the incorporation of the boraamidinate ligand into lanthanide complexes have been prepared by reaction of equimolar amounts of [Li(2)][PhB(NDipp)(2)] and LnCl(3) in tetrahydrofuran (THF), which produces "ate" complexes of the form {[Li(THF)(4)][bamLnCl(2)(THF)]}(2) [Ln = Y (9a), Pr (9b), Nd (9c), Sm (9d), Ho (9e), Er (9f), Yb (9g)] through the inclusion of the LiCl by-product. The isostructural complexes 9a-g were characterized in the solid state by X-ray crystallography, which revealed ion-separated complexes composed of a dimeric anion with a terminal and a bridging chloride ligand on each metal center and a tetrasolvated cation, Li(THF)(4). In solution, the yttrium complex 9a was characterized by multinuclear ((1)H, (13)C, (7)Li, and (11)B) NMR spectroscopy. The (1)H and (7)Li NMR spectra of the paramagnetic complexes 9b-9d showed broad resonances, but NMR spectra could not be obtained for 9e-g. The complexes 9a-g are readily soluble in THF, but insoluble in diethyl ether and hexane. The reaction of {[Li(THF)(4)][bamLnCl(2)(THF)]}(2) (Ln = Y, Sm) with an excess of trimethysilyl trifluoromethanesulfonate (TMSOTf) generates the dimeric neutral complexes {bamLnCl(THF)(2)}(2), which have been characterized by (1)H NMR and X-ray crystallography.