LAUSR

The trivalent ate complex Cp*2CeCl2K(thf) (Cp* = C5Me5) was used in a diverse set of salt metathesis reactions. Equimolar reactions with LiNiPr2, LiN(SiHMe2)2, KN(SiMe3)2, and LiCH2C6H4-o-NMe2 gave the alkali metal-free complexes Cp*2Ce(NiPr2), Cp*2Ce[N(SiHMe2)2], Cp*2Ce[N(SiMe3)2], and Cp*2Ce(CH2-C6H4-o-NMe2). Employing Cp*2CeCl2K(thf) and KC≡CtBu in a 1:2 ratio produced a hard-to-separate mixture of Cp*2Ce(C≡CtBu)2Li(thf) and [Cp*2Ce(C≡CtBu)]2(LiCl). The reaction of Cp*2CeCl2Li(Et2O) with 2 equiv of LiC≡CPh involved Cp* displacement and formation of the tetrametallic half-sandwich complex [Cp*Ce(C≡CPh)2]4(LiCl). All complexes were characterized by single-crystal X-ray structure analysis. The distinct terminal bonding behavior of the similarly-sized NiPr2 and N(SiHMe2)2, of which the latter revealed a strong Ce---HSi β-diagostic interaction, is supported by distinct paramagnetic shifts of the amido substituents in the 1H NMR spectra. Exemplarily, Cp*2Ce[N(SiHMe2)2] and Cp*2Ce(C≡CtBu)2Li(thf) have been tested for oxidation reactions with 1,4-benzoquinone and Ph3CCl, respectively.