title: Paramagnetism of aqueous actinide cations. Part I: Perchloric acid media.
abstract: A comprehensive study of actinide cation paramagnetism in acidic aqueous solution has been completed in perchlorate media. Employing the Evans method, all the readily accessible actinide cations have been studied using our specially outfitted NMR spectrometer equipped for use with radioactive samples. The effective magnetic moments observed, ranging from 0 to 13 μB, differ from the isoelectronic lanthanides, previous solid actinide studies, and older solution studies. Actinide (IV) and (V) ions show less paramagnetic character, while some actinide (III) ions exhibit greater paramagnetic behavior than predicted from free-ion calculation. Temperature dependence of actinide magnetic susceptibilities from 5 to 80 °C are in good agreement with a Curie-like law except for U(VI), which appears to be temperature-independent. Diamagnetic behavior of Th(IV) exhibits a very low temperature dependence of the magnetic susceptibility. Some explanations for the observations are offered, and the 5f electron behavior is compared to the 4f analogues.
authors: Department of Chemistry, Washington State University , Pullman, Washington 99163, United States.
authors: Thomas F
authors: TF
authors: Wall
authors: Steve
authors: S
authors: Jan
authors: Matthieu
authors: M
authors: Autillo
authors: Kenneth L
authors: KL
authors: Nash
authors: Laetitia
authors: L
authors: Guerin
authors: Claire Le
authors: CL
authors: Naour
authors: Philippe
authors: P
authors: Moisy
authors: Claude
authors: C
authors: Berthon