The absorption spectrum of the uranyl ion in perchlorate media: Part II. The effects of hydrolysis on the resolved spectral bands

Abstract

The uranyl ion absorption spectrum was found to become more complex throughout the visible region when the uranyl ion hydrolyzes. The visible region (3300 Å–5000 Å) of the spectrum of the uranyl ion at various stages of hydrolysis has, for the first time, been resolved into individual bands. Hydrolysis was found not to affect the transition frequencies observed for uranyl ion in acidic media. However, the intensities and half-band widths of all the bands were observed to increase with hydrolysis. This information supports the idea that the observed transitions involve the OUO bonds and that hydrolysis of the uranyl ion involves the water of hydration in the equitorial positions. Over the range of conditions studied, hydrolysis was found to have no effect on the uranyl ion structure, and evidence is given against calculating thermodynamic quantities from visible spectral data for uranyl ion hydrolysis.