Vanadium complexes adipates

Finally, although cobalt complexes alone give several products, mixtures of cobalt and vanadium complexes give high yields ( 76%) of adipic acid [296-298]. 

The roles of vanadium and copper are complex and not fully understood. A large number of intermediates, including the nitroso and the diketo compound as shown by reaction 8.21 are formed. The ion V02 stoichiometrically oxidizes the diketo compound to adipic acid. This is shown by reaction 8.22. 

Most of the catalysts employed in the chemical technologies are heterogeneous. The chemical reaction takes place on surfaces, and the reactants are introduced as gases or liquids. Homogeneous catalysts, which are frequently metalloorganic molecules or clusters of molecules, also find wide and important applications in the chemical technologies [24]. Some of the important homogeneously catalyzed processes are listed in Table 7.44. Carbonylation, which involves the addition of CO and H2 to a C olefin to produce a + 1 acid, aldehyde, or alcohol, uses rhodium and cobalt complexes. Cobalt, copper, and palladium ions are used for the oxidation of ethylene to acetaldehyde and to acetic acid. Cobalt(II) acetate is used mostly for alkane oxidation to acids, especially butane. The air oxidation of cyclohexane to cyclohexanone and cyclohexanol is also carried out mostly with cobalt salts. Further oxidation to adipic acid uses copper(II) and vanadium(V) salts as catalysts. The... 

Vanadium(IV) complexes, 487 acetates, 513 acetylacetonates, 504 electrochemistry, 505 ESR spectra, 505 adenine, 568 adipates, 516 alcohols, 502 amines, 489 amino adds, 544 equilibria, 544 ammonia, 489 arsenates, 513 arsenic ligands, 496 arsines, 498 ascorbic add, 502 benzilato, 522 biguanide, 496 binucleating ligands, 561 bipyridyl, 492,494... 

There are few examples of ketone oxidation. Copper(II) and its amine complexes are useful catalysts and vanadium heteropoly acids have been employed. Cyclohexanone can be converted to the 1,2-dione, which is cleaved and dioxygenated to adipic acid. 

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