Synthesis and Structure of Yttrium and Lanthanide Bis(phosphinimino)methanides

Reaction of K{CH(PPh<INF>2</INF>NSiMe<INF>3</INF>)<INF>2</INF>} (<BO>1</BO>) with anhydrous yttrium or lanthanide trichlorides leads to [{CH(PPh<INF>2</INF>NSiMe<INF>3</INF>)<INF>2</INF>}LnCl<INF>2</INF>]<INF>2</INF> (Ln = Y (<BO>2a</BO>), Sm (<BO>2b</BO>), Er (<BO>2c</BO>), Dy (<BO>2d</BO>), Yb (<BO>2e</BO>), Lu (<BO>2f</BO>)). The single-crystal X-ray structures of these complexes show that the methine carbon is bound to the lanthanide atom. This is supported by DFT calculations, which show a comparable interaction. Due to the similar ion radii of the lanthanides, the single-crystal X-ray structures of <BO>2a</BO>−<BO>f</BO> are isostructural. Further reaction of <BO>2</BO> with KNPh<INF>2</INF> afforded [{CH(PPh<INF>2</INF>NSiMe<INF>3</INF>)<INF>2</INF>}Ln(NPh<INF>2</INF>)<INF>2</INF>] (Ln = Y (<BO>3a</BO>), Sm (<BO>3b</BO>)). These complexes show in comparison to <BO>2</BO> a similar coordination behavior of the {CH(PPh<INF>2</INF>NSiMe<INF>3</INF>)<INF>2</INF>}^- ligand in the solid state and in solution.