PRIMARY STEPS IN THE HYDROLYZES OF 2 HETEROMETALLIC ALKOXIDES - CHARACTERIZATION OF [LITIO(OIPR)3]4 AND BAZR4(OH)(OIPR)17

Partial hydrolysis of [LiTi(OiPr)5]2 yields a tetrameric oxo-alkoxide, [LiTiO(OiPr)3]4. The compound has been characterized in solution by H-1 and C-13 NMR spectroscopy and in the solid state by X-ray crystallography. The molecule crystallizes in the space group C2/c with a = 18.460(3) angstrom, b = 17.904(3) angstrom, c = 15.832(2) angstrom, beta = 90.11 (0)-degrees, and Z = 4. Titanium and oxo atoms are located in a middle layer with Li atoms in layers above and below, supported by alkoxide bridges. The similarity to ferroelectric titanates is evident in the coordination sphere of Ti in [LiTiO(OiPr)3]4. Addition of 1 equiv of water to BaZr4(OiPr)18 in THF yields the hydroxide BaZr4(OH)(OiPr)17 in a simple acid/base ligand exchange reaction. Characterization by X-ray diffraction shows that the molecule crystallizes in the C2/c space group, with dimensions a = 58.735(12) angstrom, b = 12.555(13) angstrom, c = 19.321(4) angstrom, and beta = 94.17(1)-degrees (Z = 8). Variable-temperature H-1 and C-13 NMR data are also reported, revealing ligand site exchange local to BaZr2 triangles. The hydroxide ligand adopts a mu3-Site, bridging the barium and two zirconium atoms. In both cases, the metal stoichiometry has been retained in the final product.