Raman and infrared spectroscopic studies of the uranyl ion: the symmetric stretching frequency, force constants, and bond lengths

Abstract

The symmetric stretching frequency of the uranyl ion has been measured for some uranyl compounds with the use of Raman excitation. The symmetric and asymmetric stretching frequencies have been used in the calculation of stretching and interaction force constants from which have been derived an estimate of the uranium–oxygen bond lengths by use of Badger's rule. These bond lengths are in good agreement with the few crystallographic data available. Previous calculations of force constants have ignored interaction constants, and bond-length determinations have relied upon an estimate of the bending frequency of the uranyl ion or upon force constants derived from the asymmetric stretching frequency only. The present measurements confirm that the uranyl ion is linear or very nearly so. The overtone and combination bands of some uranyl nitrate complexes have been re-investigated.