Chapter 19: Structural Chemistry of Transuranium Phosphonates Check Access

In this chapter, 13 transuranium phosphonates are described that were synthesized via in situ hydrothermal reduction reactions. The majority of these compounds contain actinides in the +4 oxidation state, with only two being exceptions. Under mild hydrothermal conditions An⁶⁺ (An=Np, Pu) can be reduced to An⁴⁺ even in the presence of certain oxidation agents so long as this process is also driven by the formation of highly insoluble products. The structures vary from 1D chains to 3D frameworks, representing an amazingly diverse group of compounds. Some of these compounds are further characterized by magnetic susceptibility measurements and UV–vis–NIR spectroscopy. The comparisons between transuranium elements and their possible surrogates, thorium, uranium, and cerium, are discussed in this work. In most cases each element displays unique chemistry. Therefore the study of transuranium elements is essential for developing a deep understanding of their chemistry and predicting their behavior in the environment. The preparation of structurally rich heterobimetallic compounds by reacting redox-inactive actinides and in situ hydrothermal reductive transuranics is also demonstrated.