Synthesis and crystal structure of mono-chelating (chiral) ether side chain cyclopentadienyl lanthanide complexes with a symmetric tetradentate ligand

LnCl(3) reacted with three equivalents of methoxyethylcyclopentadienyl pota ssium in tetrahydrofuran (THF), followed by treatment with trans-(+/-)-2,2' -[1,2-cyclohexanediylbis(iminomethyl)] diphenol gave a binuclear mono(metho xyethylcyclopentadienyl)samarium complex [eta(5):eta(1)-Cp'Sm] [(mu:eta-OC2 0H20N2O)](2)[eta(5)-Cp'Sm] (1), and bis(methoxycyclopentadienyl) ytterbium, [Cp-2'Yb](2)(OC20H20N2O) (2) (Cp' = MeOCH2CH2C5H4). The X-ray determinatio n of complex 1 shows that the molecule is a dimer, in which two (MeOCH2CH2C 5H4)Sm(mu:eta-OC20H20N2O) units are connected to two bridging oxygen atoms of Schiff base ligands. The average Sm-C distance is 2.769(7) Angstrom, whi le that of Sm-O (bridging Schiff base oxygens) is 2.401(4) Angstrom. Furthe r studies on the reaction of Cp-2'DyCl (Cp'H = MeOCH2CH2CpH) with the disod ium salt of trans-(+/-)-2.2'-[1,2-cyclohexanediylbis(iminomethyl)]diphenol resulted in an analogue of complex 1: [(MeOCH2CH2C5H4)Dy(OC20H20N2O)](2) (3 ). However, Cp-2" DyCl reacted with disodium salt of trans-(+/-)-2,2'-[1,2- cyclohexanediylbis(iminomethyl)]diphenol to give rise to the isolation of d inuclear bis(tetrahydrofurfurylcyclopentadienyl) dysprosium complex with on e molecular ligand, (Cp-2" Dy)(2)(OC20H20N2O) (4) (Cp " H = C4H7OCH2C5H5). (C) 1999 Elsevier Science Ltd. All rights reserved.