Tungsten Compounds and Their Application

A short, general discussion at the beginning emphasizes that the chemistry of tungsten compounds is rather complicated and complex. The following important facts must be taken into account. 

Examples of compounds for different valence states are given in Table 4.1 [4.1]. The following abbreviations are used throughout the chapter  

TABLE 4.1. Typical Examples of Tungsten Compounds for the Diiferent Valence States [4.1]. 

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A considerable amount of literature has appeared which describes the use of heteropolymolybdates and their tungsten analogs in various applications. Of these, the main applications have centered on catalysis. Of particular importance to the catalytic behavior of heteropoly compounds is the solubility and solvolytic behavior in both aqueous and organic media and the thermal stability and oxidation-reduction behavior. 

This volume is devoted to the four elements chromium, molybdenum, tungsten, and uranium. The study of each of these provides much that is fascinating to the chemist, and much that calls for elucidation and further research. The growing importance of the metals and their compounds in industry, especially in the manufacture of steels and special alloys, and in the production of glazes and pigments, emphasises their claims to interest. The use of tmigsten in electrical work is continually finding wider application. 

G. Winter, Tungsten and Special Tungsten Compounds—Their Application in Modem Technology, paper presented at the Annual ITIA Meeting, Huntsville, USA transcript of papers ITIA, London (1994). 

Despite the fact that sulfur metal compounds poison many metallic catalysts, transition-metal compounds such as molybdenum and tungsten, while converting to sulfides during use, retain their ability to hydrogenate aromatic compounds (6) because their exceptional resistance to poisons. TMS find their application in removal of sulfur (HDS), removal of nitrogen (HDN), and petroleum feedstock upgrading (hydrogenation). 

Such vinylsilver compounds ought to And many applications in synthesis. Reports already emerging deal with their useinattachingthe CF,-CF C(CFj)— group to a metal such as iron or tungsten. ... 

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