Synthesis, characterization and soft transformation of some bis(cyclopentadienyl) Ti(IV) and Zr(IV) complexes of Schiff's base ligands to nano‐sized titania or zirconia materials

Abstract

AbstractSome bis(cyclopentadienyl) complexes of Ti(IV)and Zr(IV) have been synthesized by the metathetical reactions of Cp2MCl2 with the sodium salt of monofunctional bidentate Schiff's base ligands in 1:1 and 1:2 stoichiometry in anhydrous THF. All the derivatives of the types Cp2MCl2−n{O(C6H4)CH6H5}n and Cp2MCl2−n{OC(CH3)(R)6H5}n (where R = CH3 or C6H5 and n = 1 or 2) have been characterized by elemental analyses, molecular weight measurements, FT‐IR and ‐NMR [1H and 13C{1H}] studies. The FAB mass spectra of a few representative complexes and the molecular weight measurements in freezing benzene indicate their monomeric nature in solution. Spectral studies appear to indicate mono‐ and bi‐dentate mode of attachment of the ligand in solution and in the solid state, respectively. Thermogravimetric analyses (TGA) of Cp2TiCl{O(C6H4)CH} (1) and Cp2ZrCl{O(C6H4)CH} (7) indicate their low thermal stability. Transformations of some of these complexes to pure titania (TiO2)/zirconia (ZrO2) have been observed at relatively low sintering temperatures. Powder X‐ray diffraction (XRD) and scanning electron micrograph (SEM) studies suggest the nanocrystalline nature of these materials. Copyright © 2007 John Wiley & Sons, Ltd.