Wilson Richard E, Stegman Samantha, Tarlton Michael L
Chemical Sciences and Engineering Division, Argonne National Laboratory (ANL), 9700 South Cass Avenue, Lemont, Illinois 60439, United States.
Inorg Chem. 2021 Dec 6;60(23):17480-17486. doi: 10.1021/acs.inorgchem.1c01858. Epub 2021 Nov 12.
The preparation of two new neptunium hydroxide compounds synthesized in concentrated potassium and rubidium hydroxide is reported. The phases K[(NpO)(OH)]·4HO and Rb[(NpO)(OH)]·2HO were prepared and their chemical structures determined using single-crystal X-ray diffraction. Raman spectra of the compounds are also presented. The newly synthesized phases are structurally related to NpO and Na[NpO(OH)]. The potassium-containing phase reported here consists of infinite chains of edge-sharing neptunium hydroxide polyhedra but lacking the cation-cation interactions (CCIs) observed in NpO and Na[NpO(OH)]. Rb[(NpO)(OH)]·2HO is a an expanded three-dimensional framework based on NpO CCIs like those observed in NpO and Na[NpO(OH)]. Together these complexes begin to develop a structural series of neptunium(V) oxides and hydroxides of varying dimensionalities within the alkali-metal series. The potential roles of the alkali-metal cations and neptunyl(V) CCIs in directing the resulting structures are discussed.
