(2,5-Bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrolyl)yttrium and -lutetium complexes - Synthesis and Structures

The reaction of 2,5-bis{[(2,6-diisopropylphenyl)imino]methyl}pyrrole (diP(2)-pyr)H with nBuLi and KH resulted in the lithium compound [(diP(2)-pyr)Li] and the potassium compound [(diP(2)-pyr)K], respectively. Transmetallation of [(dip(2)-pyr)Li] with YCl(3) in thf afforded the "ate complex" [(dip(2)-pyr)YCl(3)Li(thf)(3)], in which an additional equivalent of LiCl is coordinated as a four-membered Li-Cl-Y-Cl metallacycle. In contrast, treatment of [(dip(2)-pyr)K] with anhydrous yttrium and lutetium trichloride resulted in [(dip(2)-pyr)LnCl2(thf)(2)] (Ln = Y, Lu). Obviously, by using the potassium reagent [(diP(2)-pyr)K] the formation of "ate complexes" is inhibited. Reaction of NaC(5)H(5) with [(dip(2)-pyr)YCl(3)Li(thf)(3)] or [(dip(2)-pyr)YCl(2)(thf)(2)] afforded the metallocene [(dip(2)-pyr)Y(eta(5)-C(5)H(5))(2)], A significant difference in reactivity between the compounds [(dip(2)-pyr)YCl(3)Li(thf)(3)] and [(dip(2)-pyr)YCl(2)(thf)(2)] could not be observed. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).