Molecular Siloxane Complexes of Rare Earth Metals—Model Systems for Silicate‐Supported Catalysts?

Participation of the oxygen atoms of the siloxane framework of ligand 1, and not only the terminal hydroxyl groups, may be required for the coordinative saturation of a metal center. This surprising conclusion was drawn from the X‐ray structure analysis of the first rare earth metal complex with this type of ligand. Compound 1 serves as a molecular model for SiO₂ supports for transition metal catalysts. (Figure Presented.)