Spectroscopic properties and electronic structure of uranyl complex compounds (Review)

Fundamental problems of the photophysics of uranyl complex compounds are considered. Works on the spectroscopy of uranyl compunds in a wide spectral range from the visible to the vacuum UV region of the spectrum are reviewed. The characteristics of their electronic structure are discussed. It is shown that the optical properties of uranyl compounds are determined by electronic transitions from three occupied molecular orbitals. The highest occupied orbital of the uranyl complex is predominantly ligand in character; the lower-lying occupied orbitals have a significant contribution from uranyl orbitals. Intiation of electronic transitions from shielded valent orbitals increases the probability of nonradiative deactivation of electronic excitation of the uranyl complex. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 6, pp. 818–831, November–December, 1998