Actinide coordination chemistry – a unique example of a homoleptic complex of nine-coordinate thorium(IV)

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.

Structure, Stability, and Electronic Properties of Dimethyl Sulfoxide and Dimethyl Formammide Clusters Containing Th(4.)

By using accurate density functional theory calculations, we have studied the complexes of Th(4+) with dimethyl-sulfoxide (DMSO) and dimethyl-formammide (DMF) molecules. These solvents are prototypes for oxygen-donor organic environments in which the oxygen atom is connected to S and C atom, respectively. Extended structural, energetic, and electronic structure analysis has been performed to provide a complete picture of the physical properties at the basis of the interaction of Th(4+) with the two solvents. By using a cluster grow approach, we have found that, very likely, the first solvation shell contains nine molecules in the case of DMSO, while it contains eight molecules for DMF. The theoretical results shown here are in agreement with experimental data taken from the literature.

New Efficient Synthesis of [UI4(MeCN)4]. X-ray Crystal Structures of [UI2(MeCN)7][UI6], [UI4(py)3], and [U(dmf)9]I4

Reaction of UCl4 and excess Me3Sil in acetonitrile provides a convenient route to [Ul4(MeCN)4] (1), which was isolated in excellent yield and crystallized in acetonitrile as the ion pair complex [Ul2(MeCN)7][Ul6] (2). Compound 1 was transformed in pyridine (py) and dimethylformamide (dmf) into the Lewis base adducts [Ul4(py)3] (3) and [Ul4(dmf)6] (4). Crystals of 3 and [U(dmf)9]l4 (5) were obtained by slow diffusion of diethyl ether into pyridine or dmf solutions of 1; compound 5 is the first tetracationic {U4+} entity to have been crystallographically characterized.