Tungsten metal vapor synthesis

Bis(benzamidinate)zirconium catalysts, for stereoselective propylene polymerization, 11, 708 Bis(r -benzene)tungsten, as metal vapor synthesis milestone, 1, 236... 

The metal vapor technique, in which a metal is vaporized from a resistively heated tungsten container under high vacuum and is cocondensed with a potential ligand at -125 to -196°C, had proven useful in the synthesis of a variety of unusual low-valent transition metal complexes (67-71). With lanthanide metals, this method not only has generated low oxidation state species, but it has also provided the opportunity to study zero-valent lanthanide chemistry on an atomic/molecular basis for the first time. These studies have been important in identifying new directions in organolanthanide chemistry. 

Vapor deposition techniques have been extensively studied for the fabrication of metal and metal oxide structures. Indeed, the first reported tungsten oxide nanorods were essentially grown by this method. This groundbreaking synthesis of W02.72 leaves room for improvement, however, as it requires a reaction temperature of 1600°C in an argon atmosphere. Additionally, the researchers found the reaction product to be commingling WO2.72 nanorods and WO3 platelets rather than pure nanorods. Later,... 

The IF structures and nanotubes for WS2 were first observed during hydrodesulfurization using thin films of tungsten [50]. Tenne and coworkers [59-62] developed a precursor synthetic method for obtaining both IF-MS2 (M = Mo, W) and nanotubes. The method is based on a gas-phase reaction between partially reduced metal oxides and hydrogen sulfide. The synthesis consists of three steps. First is the formation of the oxide MO3. For M = W, this step involves the preparation of WO3 by heating a mngsten filament in the presence of wate vapor. The second step is the partial reduction of the oxide to an amorphous suboxide MO3 c. For W, the reduction of WO3 produces in the form of needle-... 

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