Laser Raman spectra and normal coordinate analysis of some uranyl tetrachloride complexes

Laser Raman spectra of uranyl tetrachloride complexes [K2UO2Cl4, Rb2UO2Cl4, Cs2UO2Cl4, (NH4)2UO2Cl4] have been measured in the region from 3500 to 10 cm-1. Vibrational assignments as well as normal coordinate analyses have been carried out with the assumption that all the complexes contain discrete (UO2Cl4)2- ions belonging to a point group D/sub 4h/. To understand the nature of the uranyl bonds in the complexes, approximate π-bonding energies of such bonds have been estimated from the U--O stretching force constants. The reliability of the values obtained are discussed in detail on the basis of Mulliken's magic formula