ORGANOMETALLIC COMPOUNDS OF THE LANTHANIDES - CXXI - DONOR-SUBSTITUTED LANTHANIDOCENES - SYNTHESIS OF MIXED UNBRIDGED LANTHANIDOCENE CHLORIDE AND ALKYL DERIVATIVES

Stepwise reaction of ScCl3(THF)(3) and the lanthanide trichlorides LnC l(3)(THF)(n) (Ln = Nd, Sm, Ho, Lu) first with (dimethylaminoethyl)cycl opentadienyl potassium (KCpDo) and then with tetramethylcyclopentadien yl sodium (NaCp(H)) or with pentamethylcyclopentadienyl sodium (NaCp* ), respectively, yields the mixed sandwich complexes (CpCp)-Cp-Do(ScC l)-Sc-H (1), (CpCp)-Cp-Do(H)LnCl {Ln = Nd (2), Sm (3), Ho (4), Lu (5) } and (CpCp)-Cp-DoLuCl (6), respectively. Treatment of 1-5 with methy l lithium in Et2O afforded the chiral alkyl derivatives (CpCp)-Cp-Do( ScMe)-Sc-H (7) and (CpCp)-Cp-Do(H)LnMe {Ln = Nd (8), Sm (9), Ho (10), Lu (11)}, respectively. Reaction of 6 with LiCH2SiMe3 yields the corr esponding alkyl derivative (CpCp)-Cp-DoLuCH2SiMe3 (12). The new compl exes were characterized by elemental analysis, MS and NMR spectroscopy , as well as by single crystal X-ray structure analysis (1 and 7). (C) 1998 Elsevier Science S.A. All rights reserved.