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

Reaction of K{CH(PPh 2 NSiMe 3 ) 2 } ( 1 ) with anhydrous yttrium or lanthanide trichlorides leads to [{CH(PPh 2 NSiMe 3 ) 2 }LnCl 2 ] 2 (Ln = Y ( 2a ), Sm ( 2b ), Er ( 2c ), Dy ( 2d ), Yb ( 2e ), Lu ( 2f )). 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 2a − f are isostructural. Further reaction of 2 with KNPh 2 afforded [{CH(PPh 2 NSiMe 3 ) 2 }Ln(NPh 2 ) 2 ] (Ln = Y ( 3a ), Sm ( 3b )). These complexes show in comparison to 2 a similar coordination behavior of the {CH(PPh 2 NSiMe 3 ) 2 } - ligand in the solid state and in solution.