Reactivity of a Neutral Yttrium(III) Trimethyl Complex toward Brønsted and Lewis Acids

Abstract

The present study corroborates that the neutral tridentate N‐ligand trimethyl‐triazacyclononane (Me3TACN) qualifies as a versatile platform to study selective ligand exchange with rare‐earth‐metal alkyl complexes, herein [(Me3TACN)YMe3]. Treatment with Brønsted‐acidic bis(dimethylsilyl)amine, HN(SiHMe2)2, gave selectively the mono‐exchanged heteroleptic complex [(Me3TACN)YMe2{N(SiHMe2)2}]. Depending on the molecular ratio employed, the reaction of [(Me3TACN)YMe3] with AlMe3 resulted in the isolation/crystallization of [(Me3TACN)YMe2(AlMe4)] [1:1] or ion‐separated [(Me3TACN)YMe(AlMe4)][AlMe4] [1:2] and [(Me3TACN)YMe(AlMe4)][Al2Me7] [1:3]. Analogous reactions with the heavier group 13 methyls GaMe3 and InMe3 generated mixed methyl/tetramethylgallato complex [(Me3TACN)YMe2(GaMe4)] and ion‐separated [{(Me3TACN)YMe2}2{µ‐Me}][InMe4]. Finally, dimethylalane, HAlMe2, converted [(Me3TACN)YMe3] into heteroaluminate [(Me3TACN)Y(HAlMe3)3], representing an AlMe3‐supported, molecular yttrium trihydride complex. All compounds were investigated by single crystal X‐ray diffraction (SC‐XRD), homo‐ and heteronuclear (13C, 27Al, 89Y, 115In) NMR as well as IR spectroscopies and elemental analyses.