Synthesis and characterization of organo-scandium and yttrium complexes stabilized by phosphinoamide ligands

Halcovitch, Nathan R. and Fryzuk, Michael D. (2012) Synthesis and characterization of organo-scandium and yttrium complexes stabilized by phosphinoamide ligands. Dalton Transactions, 41 (5). pp. 1524-1528. ISSN 1477-9226

Abstract

Addition of three equivalents of phosphinoamine, (ArNHP iPr 2) [Ar = 3,5-dimethylphenyl] to M(CH 2SiMe 3) 3(THF) 2 [M = Sc, Y] precursors gives complexes of the form (ArNP iPr 2) 3M(THF) [M = Sc, Y]. In the case of scandium, addition of Sc(CH 2SiMe 3) 3(THF) 2 to (ArNP iPr 2) 3Sc(THF) affords (ArNP iPr 2) 2Sc(CH 2SiMe 3)(THF), which has been isolated and structurally characterized. In contrast, addition of Y(CH 2SiMe 3) 3(THF) 2 to (ArNP iPr 2) 3Y(THF) generates a distribution of phosphinoamide- containing products consistent with the formulations (ArNP iPr 2) 2Y(CH 2SiMe 3)(THF) and (ArNP iPr 2)Y(CH 2SiMe 3) 2(THF), as ascertained using NMR spectroscopy. Attempts to react the alkyl-containing phosphinoamide complexes with small molecules such as H 2 led to disproportionation type processes.