Niobium oxide phosgene

As a specific example of the correlations we have observed, our experimental results demonstrate that the reactions of vanadium and niobium oxide cluster cations with methanol lead to dehydrogenation of methanol under single collision conditions producing neutral formaldehyde [16]. Formaldehyde is, indeed, a major product formed from methanol over condensed-phase vanadia surfaces [17]. Another study conducted in our laboratory showed that,, Clj products were formed during the reaction between certain clusters and CCl, leaving phosgene (COClj) as the most likely neutral product [15, 18]. The decomposition of... 

Niobium(V) oxide trichloride is a significant impurity in niobium(V) chloride, which is used for the preparation of niobium metal. Indeed oxygen impurities in the high-purity niobium produced in this way originate largely with NbOCl 3, and the feasibility of its removal by phosgene treatment has been examined between 380 and 450 C [223,224] ... 

The fact that this reaction proceeds rapidly and quantitatively at room temperature demonstrates the tremendous affinity that phosgene has for the oxide ion, even when bound to such a powerful oxide scavenger as niobium(V). Analogous results have been found for the tantalum system, in both room-temperature [120a] and high-temperature ionic liquids [1977c]. 

Tungsten(VI) oxide tetrachloride is a common impurity in tungsten(VI) chloride. By anaiogy with niobium(V) oxide trichloride (Section 9.2.2), phosgene might have been expected to convert WOCi to WClj, according to ... 

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