Synthesis of Coordinatively Unsaturated Tetravalent Actinide Complexes with η⁵ Coordination of Pyrrole

Abstract

The synthesis of new actinide complexes utilizing bridged α-alkyl-pyrrolyl ligands is presented. Lithiation of the ligands followed by treatment with 1 equiv of actinide tetrachloride (uranium or thorium) produces the desired complex in good yield. X-ray diffraction studies reveal unique η(5):η(5) coordination of the pyrrolyl moieties; when the nonsterically demanding methylated ligand is used, rapid addition of the lithiated ligand solution to the metal precursor forms a bis-ligated complex that reveals η(5):η(1) coordination as determined by crystallographic analysis.

Unique Four-Electron Metal-to-Cage Charge Transfer of Th to a C82 Fullerene Cage: Complete Structural Characterization of Th@C3v(8)-C82

“…The short Th–cage contacts also occur between Th1 and cage carbons C03E, C14E, and C16E with the distances ranging from 2.411(9) to 2.494(10) Å, suggesting a significant metal–cage interaction. Note that such a Th···C orientation is very different from that observed for conventional (C 5 Me 5 ) 3 ThH or (C 5 Me 5 ) 2 ThX 2 complexes, in which the metal is centered over the cyclopentadienide ring with a Th–(ring centroid) distance of around 2.5 Å. − The metal···cage orientation in Th@C 82 is also unlike that observed for the majority of lanthanide EMFs (i.e., M@ C 2 v (9)-C 82 , M = La, Ce, Gd, Sm, etc. ), ,− in which the endohedral metal is residing under a hexagon.…”

Reactivity of Multimetallic Thorium Nitrides Generated by Reduction of Thorium Azides

“…Because thorium siloxide complexes were not reported to date, we first prepared the heteroleptic complex, [Th­(OSi­(O t Bu) 3 ) 3 Cl­(THF) 2 ], 1 , by reacting a THF solution of KOSi­(O t Bu) 3 (3 equiv) with ThCl 4 (DME) 2 at −40 °C for 16 h. Complex 1 was isolated in 69% yield from a concentrated reaction mixture in toluene at −40 °C (Scheme S1 and Figure ). The synthesis of 1 requires the use of low temperature to prevent ligand scrambling which is common in actinide alkoxide, aryloxide, and amide chemistry and has resulted in a scarce number of synthetic and reactivity studies of heteroleptic complexes of thorium …”

Computational Study of Reduction Potentials of Th4+ Compounds and Hydrolysis of ThO2(H2O)n, n = 1, 2, 4

“…With the increasing energy dependence of our standard of living and quality of life, the environmental impacts of energy production weigh heavily on continued development. One proposal to reduce overall environmental atmospheric emissions and anthropogenic climate change is to increase the amount of civilian energy production based on nuclear fission; however, the extraction and use of nuclear fuels leads to many additional problems of storage, waste reduction, contamination, and remediation. , A recent resurgence in environmentalism has led to an increase of interest in the solution and coordination behavior of the actinides. − All of the actinide series are radioactive and have unique chemistry. Significant areas of fundamental research remain to be explored in actinide science and actinide coordination chemistry, in particular, if you compare the amount of research in this area to that of the early first row transition metals…”