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. Application of a similar protocol for the smallest rare-earth-metal scandium led to the isolation of ate complex [Li(thf)][LiSc(CHSiMe)] as the preferred crystallized product. Here, the reaction of adduct ScCl(thf) and LiCHSiMe was performed in EtO/-hexane, in the absence of additional THF. The reaction of LaCl(thf) with 3 equiv. of LiCHSiMe in THF/EtO at -40 °C yielded the ate complex [Li(thf)][La(CHSiMe)(thf)], which is the first of its kind.