Syntheses and characterization of a new class of zirconia precursors of oxime-modified zirconium(IV) isopropoxide

Abstract

Some oxime modified complexes of the type [Zr{OPri} 4-n{L}n] {where, n = 1-4 and LH=(CH3) 2C=NOH (1-4) and C9H16C=NOH (5-8)} have been synthesized by the reaction of [Zr(OPri)4·Pr iOH] with oximes, in anhydrous refluxing benzene. These synthesized complexes were characterized by elemental analyses, molecular weight measurements, ESI-mass, FT-IR and NMR (1H and 13C{ 1H}) spectral studies. The ESI-mass spectral studies indicate dimeric nature for [Zr{OPri}2{ONC(CH3) 2}2] (2), [Zr{OPri}3{ONC 10H16}] (5) and [Zr{OPri}{ONC 10H16}3] (7) and monomeric nature for [Zr{ONC10H16}4] (8). Oximato ligands appear to bind the zirconium in side on manner in all the complexes. Thermogravimetric curves of (2) and (8) exhibit multi-step decomposition with the formation of ZrO2, under nitrogen atmosphere. Sol-gel transformations of precursors (5), (6), (7) and (8) in organic medium, yielded nano-sized tetragonal phase of zirconia samples (a), (b), (c) and (d), respectively, on sintering at ∼600 C. All these samples were characterized by Powder XRD patterns and EDX analyses. Surface morphologies of these samples were investigated by SEM images. © 2013 Springer Science+Business Media New York.