THE INFRARED SPECTRA OF SOME URANYL COMPOUNDS

The infrared spectra for the di- and hexa-hydrates of uranyl nitrate, for anhydrous uranyl acetate, and for sodium zinc uranyl acetate hexahydrate have been obtained using the potassium bromide pressed disk technique. Where possible, samples were prepared by freeze-drying aqueous solutions of the appropriate compound and potassium bromide. The uranyl nitrate hydrates gave spectra with peaks characteristic of both nitrate and nitrato groups. For uranyl acetate the type of spectra obtained depended upon the ratio of uranyl acetate to potassium bromide in the freeze-dried mixture. It is postulated that, for relatively large ratios of uranyl acetate to potassium bromide, the carbonyl oxygen atoms of the acetate groups are chelated to the uranium atom. The spectrum of sodium zinc uranyl acetate hexahydrate is quite similar to that reported by Jones for sodium uranyl acetate. Using the 933 cm −1 peak, the Beer–Lambert law was obeyed for samples prepared by freeze-drying solutions containing uranyl nitrate and potassium bromide.