Structural Periodicity in Plutonium(IV) Sulfates

The chemistry of tetravalent Pu with sulfate is explored in a series of single-crystal X-ray diffraction studies of the alkali metal plutonium sulfate compounds. Five new structures of Pu(IV) sulfates are presented including the structure for the α-phase of Pu(SO4)2(H2O)4, Na10Pu2(SO4)9(H2O)4, K8Pu2(SO4)8(H2O)5, Rb8Pu2(SO4)8(H2O)4, and Cs4Pu(SO4)4(H2O)2. Changes in structure and stoichiometry are seen down the alkali-metal series despite identical reaction conditions for each of the complexes. Comparison to the other known An(IV) sulfates, Group IV sulfates, and Ce(IV) reveals limited similarity in stoichiometry and structure across the actinide series and their homologues. Marked color changes are observed down the series indicating strong interactions between the plutonium ions and the ligands in these complexes.本研究通过一系列碱金属硫酸钚化合物的单晶X射线衍射（single-crystal X-ray diffraction）实验，系统探究了四价钚与硫酸盐的配位化学行为。本文报道了五种新型四价钚硫酸盐晶体结构，涵盖Pu(SO4)2(H2O)4的α相、Na10Pu2(SO4)9(H2O)4、K8Pu2(SO4)8(H2O)5、Rb8Pu2(SO4)8(H2O)4以及Cs4Pu(SO4)4(H2O)2的晶体结构。尽管各配合物的合成反应条件完全一致，但沿碱金属元素序列，其晶体结构与化学计量比均呈现出显著变化。将所得结构与已报道的四价锕系（An(IV)）硫酸盐、第四族金属硫酸盐以及四价铈（Ce(IV)）硫酸盐进行对比后发现，锕系元素及其同系物之间，在化学计量比与晶体结构层面的相似性较为有限。沿碱金属序列可观察到明显的颜色变化，这表明该类配合物中钚离子与配体间存在较强的相互作用。