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

Some oxime modified complexes of the type [Zr{OPr i } 4−n {L} n ] {where, n = 1–4 and LH=(CH 3 ) 2 C=NOH ( 1–4 ) and C 9 H 16 C=NOH ( 5–8 )} have been synthesized by the reaction of [Zr(OPr i ) 4 ·Pr i OH] with oximes, in anhydrous refluxing benzene. These synthesized complexes were characterized by elemental analyses, molecular weight measurements, ESI-mass, FT-IR and NMR ( 1 H and 13 C{ 1 H}) spectral studies. The ESI-mass spectral studies indicate dimeric nature for [Zr{OPr i } 2 {ONC(CH 3 ) 2 } 2 ] (2) , [Zr{OPr i } 3 {ONC 10 H 16 }] (5) and [Zr{OPr i }{ONC 10 H 16 } 3 ] (7) and monomeric nature for [Zr{ONC 10 H 16 } 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 ZrO 2 , 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.