Rare-earth-metal trimethylsilylmethyl ate complexes.

En route to putative rare-earth-metal alkylidene complex Li[Lu(CHSiMe)(CHSiMe)], according to Schumann's original protocol, the reaction of YCl with LiCHSiMe in a mixture of diethyl ether and -pentane afforded a neosilyl ate complex of composition LiY(CHSiMe). Tetrametallic complex LiY(CHSiMe) shows an unprecedented structural motif in the solid state and was further characterized by heteronuclear H/C/Li/Si/Y, as well as VT NMR and DRIFT spectroscopies. Analysis of the thermolysis product heteronuclear NMR spectroscopy and its reactivity towards benzophenone gave strong evidence for an alkylidene formation upon decomposition.

CeCl /n-BuLi: Unraveling Imamoto's Organocerium Reagent.

CeCl (thf) reacts at low temperatures with MeLi, t-BuLi, and n-BuLi to isolable organocerium complexes. Solvent-dependent extensive n-BuLi dissociation is revealed by Li NMR spectroscopy, suggesting "Ce(n-Bu) (thf) " or solvent-separated ion pairs like "[Li(thf) ][Ce(n-Bu) (thf) ]" as the dominant species of the Imamoto reagent. The stability of complexes Li Ln(n-Bu) (thf) increases markedly with decreasing Ln size.