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Synthesis and characterization of some bis (cyclopentadienyl)titanium(IV) complexes with internally functionalized oximes(LH): sol–gel transformations of Cp 2 TiCl 2 , Cp 2 TiClL and Cp 2 TiL 2 to nano‐sized anatase titania
Author(s) -
Chaudhary Archana,
Sharma Namita,
Dhayal Veena,
Saxena Arpita,
Nagar Meena,
Bohra Rakesh
Publication year - 2011
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.1742
Subject(s) - chemistry , cyclopentadienyl complex , stoichiometry , titanium , nmr spectra database , monomer , mass spectrum , stereochemistry , crystallography , medicinal chemistry , spectral line , mass spectrometry , organic chemistry , catalysis , chromatography , physics , polymer , astronomy
Some bis (cyclopentadienyl)titanium(IV) complexes of the type [Cp 2 TiCl 2− n {L} n ] {where, n = 1 or 2; L = ONC(R)Ar; R = H or CH 3 and Ar = C 5 H 4 N‐2, C 4 H 3 O‐2 or C 4 H 3 S‐2} have been synthesized by the metathetical reactions of Cp 2 TiCl 2 with the sodium salt of internally functionalized oximes in 1:1 and 1:2 stoichiometry in anhydrous THF. All these red to brown colored solid derivatives have been characterized by elemental analyses, FT‐IR and NMR ( 1 H and 13 C{ 1 H}) spectral studies. The FAB mass spectra of some representative derivatives indicate their monomeric nature. Oximato ligands in all the complexes appear to bind the titanium via N and O in a dihapto ( ${\bf \eta}^{2}$ ‐N, O) manner in the solid state. Thermogravimetric curves of [Cp 2 TiCl{ONC(CH 3 )C 5 H 4 N‐2}] and [Cp 2 Ti{ONC(CH 3 )C 5 H 4 N‐2} 2 ] suggest the formation of hybrid materials CpTiO(Cl) and Cp 2 TiO, respectively, as the final products at 900 °C under nitrogen atmosphere. Sol–gel transformations of Cp 2 TiCl 2 , [Cp 2 TiCl{ONC(CH 3 )C 5 H 4 N‐2}] and [Cp 2 Ti{ONC(CH 3 )C 5 H 4 N‐2} 2 ] yielded titania a–c, respectively, at low sintering temperature (600 °C). The powder XRD patterns, IR as well as Raman spectra of all these oxides indicate the formation of nano‐sized anatase phase. The SEM images of titania a–c indicate agglomers like surface morphologies. The absorption spectra of a–c exhibit an energy band gap in the range of 3.47–3.71 eV. Copyright © 2011 John Wiley & Sons, Ltd.