Rare-Earth Metal Phenyl(trimethylsilyl)amide Complexes

The reactions of common rare-earth metal chloride, borohydride, and triflate precursors - LnCl(3)(thf)(x), Ln(BH4)(3)(thf)(3), and La(OTf)(3) - with alkali metal amide complexes M[N(SiMe3)(C(6)H(3)iPr(2)-2,6)] (M[NRR']; M = Li, K) were investigated in thf or hexane as a solvent. A diverse range of products was obtained comprising alkali metal-free mono(rare-earth metal) complexes Y[NRR']Cl-2(thf)(3) and Ln[NRR'](2)(BH4)(thf) (Ln = Nd, La), as well as the mononeodymium ate complex {Nd[NRR'](2)(BH4)(2)}{Li(thf)(4)} and polymeric ate complexes {La[NRR'](2)(thf)(mu-Cl)K(thf)(2)(mu-Cl)}(n) and {Nd[NRR'](2)(mu-BH4)Li(thf)(2)(mu-BH4)}(n). All compounds were characterized by NMR (H-1 and C-13) and FTIR spectroscopy, elemental and X-ray structure analyses. The lithium salts Li[NRR'](thf)(3) and Li-4(OTf)(4)(thf)(6) were isolated as side products and structurally characterized. The homoleptic complex La[NRR'](3) was prepared following two synthesis protocols in hexane, either by reacting Ln[NRR'](2)(BH4)(thf) with 1 equiv. of K[NRR'] or treatment of LaCl3(thf)(1.25) with 3 equiv. of K[NRR'].