ISOLATION AND STRUCTURAL CHARACTERIZATION OF THE POLYMETALLIC ZIRCONIUM ALKOXIDE COMPLEXES, ZR3O(OCH2CME3)(9)CL, ZR3O(OCME3)(9)(OH), AND NA4ZR6O2(OET)(24)

Three polymetallic zirconium alkoxide complexes have been isolated and structurally characterized which show that by proper combination of z irconium precursor and alkoxide, this small class of compounds can be expanded. The trimetallic neopentoxide complex [(NpO)(2)Zr](3)(mu-ONp) (3)(mu(3)-Cl)(mu(3)-O), 1, (Np = CH2CMe3) can be isolated from the rea ction of ZrCl4 with four equivalents of KOCH2CMe3 in THF. The trimetal lic telt-butoxide complex, (2)Zr](3)(mu-O'Bu)(2)(mu-OH)(mu(3)-O'Bu)(mu (3)-O), 2, can be isolated from the reaction of ZrCl4 with 3.3 equival ents of LiOCMe3 in THF. The reaction of Zr(OEt)(4) with one equivalent of NaOSiMe3 in THF formed the mixed-metal polymetallic complex, -2[(E tO)Zr](3)(mu-OEt)(7)(mu-OEt)(2)(mu(3)-O)}(2), 3. These results show th at the common M-3(mu-E)(3)(mu(3)-E)(2) structural motif with E being a ligand donor atom can be obtained with zirconium alkoxides. (C) 1998 Elsevier Science Ltd. All rights reserved.