ACTIVATION OF LANTHANIDE ACETATES VIA HETEROMETALLIC ALKOXIDES - SYNTHESIS AND MOLECULAR-STRUCTURE OF GD2ZR6(MU-4-O)2(MU-OAC)6 (MU-OPR(I))10(OPR(I))10

The mixed-metal species [Gd2Zr6(mu4-O)2(mu-OAc)6(mu-OPri)10(OPri)10] (1) was obtained by reacting anhydrous gadolinium acetate with [Zr(OPri)4(PriOH)]2. Its X-ray structure analysis reveals two Zr3Gd(mu4-O)(mu-OAc)2(OPri)10 tetrahedral clusters associated via Gdmu-OAc linkages. The zirconium and gadolinium centres are hexa- and hepta-coordinated, respectively. The analogous yttrium derivative (2) was obtained by a similar route and characterized by microanalysis, IR, H-1 and C-13 NMR spectroscopies. Control of the stoichiometry between the metals can bc achieved by varying the nature of the alkoxo group. Hydrolysis-polycondensation reactions proceed via differential hydrolysis and offered cubic zirconia containing various amounts of lanthanide oxides depending on the stoichiometry between the metals.