A novel complex loose-tube (fiber-in-tube) morphology (Nb)−SnO 2 has been prepared by conventional, single-needle electrospinning, and a mechanism for the formation of fiber-in-tube structures is proposed. The presence of niobium drives the morphology of electrospun tin oxide from dense fibers to loose tubes by enhancing the Kirkendall effect where precursor salts diffuse to the fiber surface during calcination. The highest electronic conductivity (0.02 S cm −1 ) of the cassiterite structured niobiumdoped tin oxides is observed with 5 wt % Nb doping. The loose-tube morphology materials have been further functionalized by depositing Pt nanoparticles prepared by a microwave assisted polyol method, and the samples examined by electron microscopy and studied for their electrochemical properties. The electrochemically active surface area of 13 wt % Pt on Nb−SnO 2 is >50 m 2 g −1 , and is more stable to voltage cycling than Pt/C.
A series of small-sized model π-conjugated oligomers have been prepared from thienylene and phenylene or dimethylor dimethoxy-substituted phenylene units. Crystallographic data for the methoxylated compound show a quasi-planar conformation with a non-covalent S-O interaction. The resulting strong conjugation in the gas phase has also been highlighted by UV/photoelectron spectroscopy and theoretical calculations (DFT). Indeed, for these compounds there is a large energy gap ∆E π arising from the interaction between the molecular orbitals of the isolated thienylene-phenylene species. This can be explained in terms of the energies of the two π orbitals of the dimethoxyphenylene unit, the shape of these molecular orbitals in a three-orbital interaction diagram and by the presence of the S···O interaction which re-
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