Pentamethylcyclopentadienyl-Supported Rare-Earth-Metal Benzyl, Amide, and Imide Complexes

Abstract

The half-sandwich diiodide complexes [Cp*LnI2]x (Ln = Y, Lu), obtained in high yields from Cp*Ln(AlMe4)2 (Cp*= C5Me5) and 2 equiv of ISiMe3, reacted with 2 equiv of potassium benzyl KCH2Ph in THF to afford complexes Cp*Ln(CH2Ph)2(thf). Protonolysis of Cp*Ln(CH2Ph)2(thf) with 3,5-bis(trifluoromethyl)aniline (H2NC6H3(CF3)2-3,5 = H2NArCF3) in toluene gave rare-earth-metal imide complexes [Cp*Ln(NC6H3(CF3)2-3,5)(thf)x]2 (Ln = Y (x = 2), Lu (x = 1)). The dimeric structure of [Cp*Ln(NC6H3(CF3)2-3,5)(thf)x]2 with two bridging imido ligands forming a planar Ln2N2 core was analyzed by X-ray crystallography. Treatment of Cp*Y(CH2Ph)2(thf) with H2NC6H3(CF3)2-3,5 in THF led to the monomeric bis(amide) complex Cp*Y(NHC6H3(CF3)2-3,5)2(thf)2. The reaction of Cp*Y(CH2Ph)2(thf) with 2,6-diisopropylaniline in toluene gave also the bis(amide) complex Cp*Y(NHC6H3iPr2-2,6)2(thf), whereas, in a THF solution, the formation of the labile mixed benzyl amide complex Cp*Y(HNC6H3iPr2-2,6)(CH2Ph)(thf) was observed.