Structures of homoleptic eight- and nine-coordinate uranium(IV) perchlorate complexes with sulfoxide molecules as ligands

Perrhenate and Pertechnetate Complexes of U(IV), Np(IV), and Pu(IV) with Dimethyl Sulfoxide as an O-Donor Ligand

A series of new dimethyl-sulfoxide-containing pertechnetates and perrhenates of tetravalent U, Np, and Pu were synthesized and structurally characterized by the X-ray diffractometry. In all the synthesized compounds, the actinide atoms were coordinated by eight DMSO molecules with or without an extra XO₄^- anion in the coordination sphere. This resulted in the square antiprismatic or capped square antiprismatic coordination of An atoms. Three or four XO₄^- anions play the role of outer-sphere anions. The electron and IR spectra of the compounds correlated with their crystal structure.

Hydration Structure and Hydrolysis of U(IV) and Np(IV) Ions: A Comparative Density Functional Study Using a Modified Continuum Solvation Approach

We studied the hydration and the first hydrolysis reaction of U(IV) and Np(IV) ions in an aqueous environment, applying a relativistic density functional method together with a recently proposed variant of a continuum solvation model where the solute cavities are constructed with effective atomic radii, based on charge-dependent scaling factors. In this way, one obtains improved solvation energies of charged species. We demonstrate that solute cavities, constructed with scaled atomic radii as described, permit one to calculate hydrolysis constants of acceptable accuracy. As a consequence, one is also able to estimate free hydration energies of U(IV) and Np(IV) in adequate agreement with empirical data. According to the model calculations, U(IV) is coordinated by eight to nine water molecules, while the preferred coordination number of Np(IV) is 8. For the highly charged ions under study, the modified solvation model simultaneously yields improved geometries, hydration energies, and hydrolysis constants.

Crystal Structure of Regularly Th -Symmetric [U(NO3 )6 ]2- Salts with Hydrogen Bond Polymers of Diamide Building Blocks

Hexanitratouranate(IV), [U(NO₃ )₆ ]^2- , has been crystallized with anhydrous H⁺ -involving hydrogen bond polymers connected by selected diamide building blocks. Thanks to the significant moderation of electrostatic interactions between the anions and cations, the molecular structure of [U(NO₃ )₆ ]^2- in these compounds is regularly T_h -symmetric. The f-f transitions stemming from 5f² configuration of U⁴⁺ are strictly forbidden by the Laporte selection rule in such a centrosymmetric system, so that the obtained compounds are nearly colourless in contrast to other U^IV species usually coloured in green.

Novel uranyl(vi) complexes incorporating propylene-bridged salen-type N2O2-ligands: a structural and computational approach

Synthesis of uranyl complex, [UO₂L(CH₃OH)] showing distorted pentagonal bipyramidal geometry and derived from a tetradentate dianionic ligand is reported. The computational study of the reported complex shows that its LUMO is featured with uranium f orbital character.

The reactions of TiCl3, and of UF4with TiCl3in liquid ammonia: unusual coordination spheres in [Ti(NH3)8]Cl3·6NH3and [UF(NH3)8]Cl3·3.5NH3

TiCl₃and NH₃form octaammine titanium(iii) chloride ammonia (1/6), [Ti(NH₃)₈]Cl₃·6NH₃, which is the first structurally characterized octaammine complex of a transition metal.