Hydrothermal Syntheses, Structures, and Properties of New Iodate and Selenite Compounds of Transition Metals, Lanthanides, and Actinides

Abstract

Iodate and selenite anions possessing a nonbonding, but stereochemically active lone pairs of electrons, were selected as building blocks to produce new compounds with noncentrosymmetric structures, a prerequisite for nonlinear optics (NLO). A broad range of other elements, including transition metals, lanthanides, and even actinides, were utilized to synthesize new compounds and new structures under mild hydrothermal or supercritical conditions. Another important reason for investigating iodate chemistry of actinides is to gain a better understanding of the chemistry involved with spent nuclear fuel. The success of intercalating iodic acid molecules into an existing uranyl phase provides a great example of the immobilization of 129I which is a key long-lived radionuclide in spent nuclear fuel. Single crystal X-ray diffraction measurements were carried out to determine the structures of prepared new compounds. Spectroscopic, second harmonic generation, thermal, and magnetic characterizations are additionally utilized to investigate structure-property relationships.