The crystal structures of uranyl minerals and inorganic uranyl compounds are important for understanding the genesis of U deposits, the interaction of U mine and mill tailings with the environment, transport of actinides in soils and the vadose zone, the performance of geological repositories for nuclear waste, and for the development of advanced materials with novel applications. Over the past decade, the number of inorganic uranyl compounds (including minerals) with known structures has more than doubled, and reconsideration of the structural hierarchy of uranyl compounds is warranted. Here, 368 inorganic crystal structures that contain essential U6+ are considered (of which 89 are minerals). They are arranged on the basis of the topological details of their structural units, which are formed by the polymerization of polyhedra containing higher-valence cations. Overarching structural categories correspond to those based upon isolated polyhedra (8), finite clusters (43), chains (57), sheets (204), and frameworks (56) of polyhedra. Within these categories, structures are organized and compared upon the basis of either their graphical representations, or in the case of sheets involving sharing of edges of polyhedra, upon the topological arrangement of anions within the sheets.

U6+ minerals and inorganic compounds: insights into an expanded structural hierarchy of crystal structures

https://escholarship.org/content/qt1kp1t47g/qt1kp1t47g.pdf?t=o0hb1w

Radical ligand-containing single-molecule magnets

Uranyl bearing hybrid materials: synthesis, speciation, and solid-state structures.

The crystal chemistry of uranium carboxylates

Preface. Acknowledgements. Foreword. I. Introductory material. Introduction Standards, conventions, and contents of tables. II. Tables of selected data. Selected neptunium data. Selected plutonium data. Selected auxiliary data. III. Discussion of neptunium data selection. Elemental neptunium. Neptunium aqua ions. Neptunium oxygen and hydrogen compounds and complexes. Neptunium group 17 (halogen) compounds and complexes. Neptunium group 16 compounds and complexes. Neptunium group 15 compounds and complexes. Neptunium group 14 compounds and complexes. Neptunium group 2 (alkaline-earth) compounds. Neptunium group 1 (alkali) compounds. IV. Discussion of plutonium data selection. Elemental plutonium. Plutonium aqua ions. Plutonium oxygen and hydrogen compounds and complexes. Plutonium group 17 (halogen) compounds and complexes. Plutonium group 16 compounds and complexes. Plutonium group 15 compounds and complexes. Plutonium group 14 compounds and complexes. Plutonium group 2 (alkaline-earth) compounds. Plutonium group 1 (alkali) compounds. Bibliography. List of cited authors. V. Appendices. Discussion of selected references. Ionic strength corrections. Assigned uncertainties. Index.

Chemical thermodynamics of neptunium and plutonium

The published data on the structures and properties of crystalline actinide compounds having mutually coordinated AnO2+ or AnO22+ cations as structural elements are surveyed. This cation—cation interaction is an important structure-forming factor for many crystalline compounds of Np(V) and U(VI). It strongly affects their UV-Vis and IR spectra as well as other properties. Differences and similarities between the cation—cation interactions of actinide ions in solutions and crystals are discussed. The bibliography includes 114 references.

https://iopscience.iop.org/article/10.1070/RC2004v073n01ABEH000852/pdf

Cation—cation interaction in crystalline actinide compounds

Heptavalent state of neptunium and plutonium.

The centrosymmetric title compound, [(NpO2)2(C7H4FO2)2(C10H8N2)2], contains the dimeric dioxocation (NpO2+)2 in which two of the four O atoms bridge the Np atoms Two bidentate chelating-bridging fluoro­benzoate anions link the Np atoms of the dimeric cation The N atoms of the 2,2′-bipyridine ligand occupy two positions in the equatorial plane of the distorted penta­gonal bipyramid, forming a five-membered metallacycle

Dimeric dioxocations, (NpO2+)2, in the structure of bis­(μ‐2‐fluoro­benzoato‐κ2O:O′)di‐μ‐oxo‐bis­[(2,2′‐bipyridine‐κ2N,N′)oxoneptunium(V)]

Single crystals of the Np(V) and Pu(V) benzoate complexes with 2, 2'-bipyridine were prepared. According to X-ray diffraction analysis data, they are isostructural neutral dimers with the [AnO 2 (C 10 H 8 N 2 )(OOCC 6 H 5 )] 2 (An=Np or Pu) composition. In crystals of these compounds the AnO 2 + are linked to each other in pairs, acting simultaneously as ligands and coordinating centers. Due to the cation-cationic interaction the dimeric An 2 O 4 2+ cations are formed with the very short An···An distance equal to 3.4281(5) and 3.4088(14)A for Np and Pu, respectively. The [NpO 2 (C 10 H 8 N 2 )(OOCC 6 H 5 )] 2 complex is a new representative of compounds containing a very rare system of cation-cation bonds in the structure. The cation-cation bonds and the Pu 2 O 4 2+ dimeric cations in the [PuO 2 (C 10 H 8 N 2 )(OOCC 6 H 5 )] 2 structure have been found for the first time.

Cation–cation interaction in crystal structures of Np(V) and Pu(V) benzoate complexes with 2,2′-bipyridine, [NpO2(C10H8N2)(OOCC6H5)]2 and [PuO2(C10H8N2)(OOCC6H5)]2

Single crystals of [NpO 2 L(H 2 O)].1/3H 2 O (I) and [PuO 2 L(H 2 O)].H 2 O (II) (H 2 L - orthophthalic acid) have been synthesized, their structures have been determined by X-ray structural analysis. Actinide atoms in both compounds are seven-coordinated. The interaction between actinide dioxocations and phthalate anions results in formation of infinite tubes in I and layers in II. The structures are compared with those of other phthalate compounds of hexa- and pentavalent actinides, in particular, with the structure of [UO 2 L(H 2 O)].H 2 O which differs from the structure II.

N. N. Krot

Papers

Cation—cation interaction in crystalline actinide compounds

Heptavalent state of neptunium and plutonium.

Dimeric dioxocations, (NpO2+)2, in the structure of bis(μ‐2‐fluorobenzoato‐κ2O:O′)di‐μ‐oxo‐bis[(2,2′‐bipyridine‐κ2N,N′)oxoneptunium(V)]

Cation–cation interaction in crystal structures of Np(V) and Pu(V) benzoate complexes with 2,2′-bipyridine, [NpO2(C10H8N2)(OOCC6H5)]2 and [PuO2(C10H8N2)(OOCC6H5)]2

Crystal structures of Np(VI) and Pu(VI) phthalates, [NpO2{(OOC)2C6H4}H2O]·1/3H2O and [PuO2{(OOC)2C6H4}H2O]·H2O

N. N. Krot

Papers

Cation—cation interaction in crystalline actinide compounds

Heptavalent state of neptunium and plutonium.

Dimeric dioxocations, (NpO2+)2, in the structure of bis­(μ‐2‐fluoro­benzoato‐κ2O:O′)di‐μ‐oxo‐bis­[(2,2′‐bipyridine‐κ2N,N′)oxoneptunium(V)]

Cation–cation interaction in crystal structures of Np(V) and Pu(V) benzoate complexes with 2,2′-bipyridine, [NpO2(C10H8N2)(OOCC6H5)]2 and [PuO2(C10H8N2)(OOCC6H5)]2

Crystal structures of Np(VI) and Pu(VI) phthalates, [NpO2{(OOC)2C6H4}H2O]·1/3H2O and [PuO2{(OOC)2C6H4}H2O]·H2O

Dimeric dioxocations, (NpO2+)2, in the structure of bis(μ‐2‐fluorobenzoato‐κ2O:O′)di‐μ‐oxo‐bis[(2,2′‐bipyridine‐κ2N,N′)oxoneptunium(V)]