Tungsten complexes dioxide

As in the monoene chapter, the stoichiometric and catalytic reactions of dienes with carbon dioxide will be discussed in the sequence of the transition metal applied. It is remarkable, that almost the same metals are described both in monoene and in diene/C02 chemistry. Two differences, however, should be stressed In the presence of molybdenum and tungsten complexes no interactions between dienes and carbon dioxide are reported (until now). On the other hand, palladium is a much more versatile and effective metal in diene/C02 than in monoene/CO chemistry. 

Figure 2 provides a record of the infrared intensity at 1350 cm l of sulfur dioxide with increasing temperature for Indiana coal with and without a diluent. A low flow rate of oxygen was necessary to avoid direct combustion (flashing) of the undiluted coal sample. This sample shows intense sulfur dioxide evolution over a rather short range (exotherm) followed by rather weak evolution at higher temperatures. In contrast, coal samples diluted with tungsten trioxide or other diluents to reduce the exothermic behavior show a more complex sulfur dioxide evolution curve. 

OjNSCyH, 1,2-Benzi othiazol-3(2H)one, 1,1-dioxide, chromium and vanadium complex, 27 307, 309 OjNjWCijHis, Tungsten, tricarbonyltris-(propanenitrile)-, 27 4 0jNaWC,H,2C4Hi 02, Tungstate(l -), tri-carbonyl(n -cyclopentadienyl)-, sodium, compd. with 1,2-dimethoxy-ethane(l 2), 26 343... 

Molybdenum phthalocyanine has been mentioned in the literature a number of times (143, 226, 250, 356) but has not been adequately characterized. However, molybdenum dioxide is reported to react with phthalonitrile, at 260°C, to yield a polymeric oxymolybdenum phthalocyanine (252). An early attempt to prepare tungsten phthalocyanine failed (11). There has been no mention of the complex since. 

Darensbourg DJ, Frost BJ, I-arkms DL (2001) An experimental and theoretical investigation of the carbon dioxide insertion process into the tungsten-nitrogen bond of an anionic W (0) complex. Inorg Chem 40 1993-1999... 

Galindo A, Pastor A, Perez PJ, Carmona E (1993) Bis(ethylene)complexes of molybdenum and tungsten and their reactivity towards CO2. New examples of acrylate formation by coupling of ethylene and carbon dioxide. Organometallics 12 4443 1451... 

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