Studies on organolanthanide complexes. Part 61 Synthesis and characterization of 3-oxa-pentamethylene bridged ansa-metallocene chlorides of rare earth elements

Article abstract of DOI:10.1016/S0022-328X(96)06497-2

Several complexes [O(CH₂CH₂C₅H₃R)₂LnC1] (R = ¹Bu, Ln = Y, Nd, Sm, Yb; R = SiMe₃, Ln = La, Y, Nd, Yb) were synthesized using chelating ligands and characterized by mass-, IR-, ¹H NMR-spectroscopies and elemental analyses. The spectra indicate that these complexes are unsolvated ansa-metallocene chlorides and the two bridged cyclopentadiene rings coordinate to the same metal ion with an intramolecular coordination bond between the oxygen atom of the bridge and the metal ion. These complexes are still sensitive to air and moisture, but they all have good thermal stability under inert gas and excellent solubility in hydrocarbon solvents. The reactivities of the systems of these metallocene chlorides and sodium hydride were investigated. Compared with the solubility of these complexes in a range of solvents, the influences of steric factors arising from the bulky substituents on the cyclopentadiene rings or the radial size of the metal ions are relatively slight.