Scandium Alkyl Complexes Supported by a Ferrocene Diamide Ligand

Abstract

Synthesis of a scandium dimethylbenzyl complex supported by a ferrocene diamide ligand was accomplished by alkane elimination from Sc(CH 2 Xy-3,5) 3 (THF) 2 . The scandium dimethylbenzyl complex Sc(fc[NSi( t -Bu)Me 2 ] 2 )(CH 2 Xy-3,5)(THF), 2-(CH 2 Xy-3,5)(THF), was used as a starting material for the synthesis of the corresponding chloride-bridged dimer, (2-Cl) 2, which, in turn, led to a scandium bis( neo -pentyl) ate salt, Li [ 2-Np 2 ] . Attempts to remove the coordinated THF molecule from 2-(CH 2 Xy-3,5)(THF) with AlMe 3 led to the isolation of a scandium methyl complex with two coordinated AlMe 3 molecules, 2-Me(AlMe 3 ) 2 . Compound 2-Me(AlMe 3 ) 2 led to a scandium methyl complex, 2-Me(THF) 2, by stirring in THF. All ferrocene diamido compounds were characterized by X-ray crystallography. DFT calculations on model compounds were used to explain the stability of the compounds synthesized and to probe the existence of an iron−scandium interaction. Compounds 2-(CH 2 Xy-3,5)(THF) and 2-Me(AlMe 3 ) 2 polymerize l -lactide.