Lanthanide silasesquioxanes: monomeric and functionalised complexes

Abstract

Lanthanide tris(silylamides) LnL₃ reacted with 2/3 equivalents of the trisilanol (C₆H₁₁)₇Si₇O₉(OH)₃1 in THF to give the lanthanide silasesquioxanes [(C₆H₁₁)₇Si₇O₁₂Ln(THF)₂] which are dimeric in solution at 233 K. Reaction of LnL₃ with 1 equivalent of 1 in THF resulted in complete conversion of 1 into the trisilylated compound (C₆H₁₁)₇Si₇O₉(OSiMe₃)₃ as does reaction of LnL₃ with 2/3 equivalents of 1 in toluene. Reaction of [(C₆H₁₁)₇Si₇O₁₂Ln(THF)₂] with 1 equivalent of (Me₂NCH₂CH₂)₂NMe (PMDTA) gave the monomeric complex [(C₆H₁₁)₇Si₇O₁₂Ln(PMDTA)]. The chloro-functionalised lanthanide silasesquioxane [(C₆H₁₁)₇Si₇O₁₁(OSiMe₃)LnCl(THF)] was formed by reaction of [(C₆H₁₁)₇SiO₇O₁₂Ln(THF)₂]with 1 equivalent of Me₃SiCl. New compounds have been characterised by NMR spectroscopy and by elemental analysis.