Abstract
Although it has been established that covalent functionalization of the U-O bonds in the uranyl dication (UO22+) generally requires use of strong reductants and electrophiles, little work has examined how interactions between the individual reaction components could affect final outcomes in solution. Here, the patterns of such reactivity have been studied in a UO22+-containing model system supported by a workhorse pentadentate ligand, 2,2′-[(methylimino)bis(2,1-ethanediylnitrilomethylidyne)]bis-phenol. Oxo activation and functionalization have been tested with (i) electrochemical and chemical reduction, and (ii) coordinating and noncoordinating solvents. In acetonitrile, uranyl reduction was achieved cleanly, but treatment of the reduced species with tris(pentafluorophenyl)borane (BCF) resulted in a mixture of products arising from direct electron transfer to BCF. In dichloromethane (CH2Cl2), electrochemical reduction of uranyl was achieved cleanly, but clean chemical reactivity was inaccessible. Despite these challenges, one trinuclear and oxo-deficient uranium-containing product was crystallized from CH2Cl2 solution and characterized; thus, desirable electrophilic reactivity can proceed to some degree in CH2Cl2 with BCF. Computational studies were used to investigate the properties of the trinuclear uranium product and the changes that could be inducible by further reduction. Taken together, the reactivity patterns identified here could inform design of improved systems for actinyl oxo functionalization.
| Original language | English |
|---|---|
| Pages (from-to) | 5827-5845 |
| Number of pages | 19 |
| Journal | Inorganic Chemistry |
| Volume | 64 |
| Issue number | 12 |
| DOIs | |
| State | Published - Mar 31 2025 |
Funding
This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences through the Early Career Research Program (DE-SC0019169). E.R.M. was supported by a U.S. National Science Foundation Research Traineeship (NRT) at the University of Kansas (DGE-1922649). M.Z.M. and V.-A.G. were supported by ORNL\u2019s Laboratory Directed Research and Development (LDRD) program. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated under contract no. DE-AC02-05CH11231, as well as resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under contract no. DE-AC05-00OR22725. A preprint reflecting a preliminary version of the findings reported here was posted to a preprint server.(120) This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences through the Early Career Research Program (DE-SC0019169). E.R.M. was supported by a U.S. National Science Foundation Research Traineeship (NRT) at the University of Kansas (DGE-1922649). M.Z.M. and V.-A.G. were supported by ORNL\u2019s Laboratory Directed Research and Development (LDRD) program. This research used resources of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility located at Lawrence Berkeley National Laboratory, operated under contract no. DE-AC02-05CH11231, as well as resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy under contract no. DE-AC05-00OR22725. A preprint reflecting a preliminary version of the findings reported here was posted to a preprint server.