Synthesis, characterization, and catalytic activity of divalent organolanthanide complexes with new tetrahydro-2H-pyranyl-functionalized indenyl ligands

Two series of new divalent organolanthanide complexes with the general formula [eta(5):eta(1)- {1-R-3-(C5H9OCH2)C9H5}](2)Ln(II) (R = H, Ln = Yb (3); R = Me3Si, Ln = Yb (4); R = H, Ln = Eu (5); R = Me3Si, Ln = Eu (6)) were prepared by reactions of 2 equiv. of 1-R-3-(C5H9OCH2)C9H6 (R = H (1), R = Me3Si (2)) with the lanthanide(III) amides [(Me3Si)(2)N](3)Ln(mu-Cl)Li(THF)(3) (Ln = Yb, Eu) via a one-electron reductive elimination process. Recrystallization of 6 from n-hexane afforded [eta(5):eta(1)-(C5H9OCH2C9H5Si-Me-3)](2)Eu-II center dot (C6H14)(0.5) (7), All compounds were fully characterized by elemental analyses, and spectroscopic methods. The structures of complexes 4 and 7 were additionally determined by single-crystal X-ray analyses. The catalytic activity of the complexes on methyl methacrylate and F-caprolactone polymerization was studied, and the temperatures, substituents on the indenyl ring, and solvents effects on the catalytic activity of the complexes were examined. (C) 2007 Elsevier B.V. All rights reserved.