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

摘要

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.