Journal
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
Volume 53, Issue 1, Pages 67-78Publisher
SPRINGER
DOI: 10.1007/s10971-009-2057-4
Keywords
Glycol modified precursor; Internally functionalized oximes; Heteroleptic; Oximato; Vanadia; Band gap
Categories
Funding
- CSIR-New Delhi
- DST-New Dehli
Ask authors/readers for more resources
Reaction of [VO(OPr (i) )(3)] (1) with [O(CH2CH2OH)(2)] in 1:1 molar ratio in anhydrous benzene yield glycol-modified precursor, [VO{OCH2CH2OCH2CH2O}{OPr (i) }] (2). Further reactions of (2) with internally functionalized oximes in anhydrous benzene yield heteroleptic complexes of the type [VO{OCH2CH2OCH2CH2O}{ON=C(R)(Ar)}] (3-8) {where R=CH3, Ar=C4H3O-2 (3), C4H3S-2 (4), C5H4N-2 (5); and when R=H, Ar=C4H3O-2 (6), C4H3S-2 (7), C5H4N-2 (8)}. All these derivatives have been characterized by elemental analyses, molecular weight measurements and spectroscopic techniques. The crysoscopic molecular weight measurement as well as FAB mass study suggests dimeric nature of (2). However, FAB mass spectrum of (4), and the crysoscopic molecular weight measurements of (3), (4), (5) and (6) indicate the monomeric behavior of the oximato derivatives (3-8). Hexa-coordination around vanadium(V) has been proposed for both monomeric and dimeric derivatives. Sol-gel transformations of (1), (2) or (4) to vanadia [(a), (b) or (c), respectively] have been carried out at low sintering temperature (600 A degrees C). The XRD patterns of (a), (b) or (c) indicate formation of a single orthorhombic phase in all the three cases. The SEM images suggest grain like [for (a) and (b)] and rod like [for (c)] morphology of the crystallites. IR, Raman spectra as well as EDX analyses indicate formation of pure vanadia. Absorption spectra of the vanadia (b) and (c) suggest energy band gaps of 2.53 and 2.65 eV, respectively.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available