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(CH2Xy-3,5)3(THF)2. The scandium dimethylbenzyl complex Sc(fc[NSi(t-Bu)Me2]2)(CH2Xy-3,5)(THF), 2-(CH2Xy-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-Np2]. Attempts to remove the coordinated THF molecule from 2-(CH2Xy-3,5)(THF) with AlMe3 led to the isolation of a scandium methyl complex with two coordinated AlMe3 molecules, 2-Me(AlMe3)2. Compound 2-Me(AlMe3)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-(CH2Xy-3,5)(THF) and 2-Me(AlMe3)2 polymerize l-lactide.