摘要：

Equilibrium ultracentrifugations and emf (acidity) measurements were carried out in chloride solutions for hydroxyl numbers n (average number of hydroxyls bound per uranyl) up to 1.4. Weight average degrees of polymerization between 1 and 2 were found for n < 0.8, and from 2 to somewhat less than 3 for higher values of n. A few centrifugations of uranyl perchlorate and nitrate solutions indicated that polymerization is similar in these media. These results indicated that hydrolysis schemes previously proposed which include species no higher than dimers cannot be complete. Further, the intepretation earlier reported of emf (acidity) data by a core-link mechanism, whether a continuous or limited series of polymers is involved, conflicts with present results. An interpretation involving polymers no larger than trimers which are compatible with ultracentrifugation and emf measurements is presented. Comparison of acidity measurements in chloride and perchlorate solutions suggests that there is some difference in the hydrolysis schemes for the two media. Volume and refractive index increments for U(VI) in chloride are presented as a function of n. (auth)

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