Sounding out the Reactivity of Trimethylyttrium

The fundamental reactivity of amorphous [YMe3]n was representatively examined:  toward GaMe3 as
a Lewis acid, 9-fluorenone as a carbonyl substrate, and tetramethyldisilazane (HN(SiHMe2)2) as a Brønsted
acid. The products obtained from the 3-equiv reactions were spectroscopically and X-ray crystallographically identified. Y(GaMe4)3 shows Y- - -Ga distances of 3.0393(4) and 3.0502(3) Å, which are significantly
shorter than the Y- - -Al distances in Y[AlMe4]3[Al2Me6]0.5 (av 3.068 Å). The homoleptic alkoxide
[Y(OC14H11)3]x bearing sterically demanding 9-Me-fluorenoxy ligands documents high methyl group
transfer economy via the 1,2-addition reaction of [YMe3]n to 9-fluorenone; it was obtained in single-crystalline form in a minor byproduct, the asymmetric dimer [Y(OC14H11)2(μ-OC14H11)]2(9-fluorenone).
The previously elusive unsolvated complex {Y[N(SiHMe2)2]3} also shows a dimeric molecular
composition, {Y[N(SiHMe2)2]2[μ-N(SiHMe2)2]}2, featuring asymmetrically bridging silylamide ligands
and Y- - -SiH multi-β-agostic interactions in the solid state [(Y- - -Si)min 3.0521(7) Å, (Y- - -H)min 2.41(3) Å, ν(Si−H)agostic 1931 cm-1].