|
1
|
Straub MD, Ouellette ET, Boreen MA, Britt RD, Chakarawet K, Douair I, Gould CA, Maron L, Del Rosal I, Villarreal D, Minasian SG, Arnold J. A Uranium(II) Arene Complex That Acts as a Uranium(I) Synthon. J Am Chem Soc 2021; 143:19748-19760. [PMID: 34787416 DOI: 10.1021/jacs.1c07854] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Two-electron reduction of the amidate-supported U(III) mono(arene) complex U(TDA)3 (2) with KC8 yields the anionic bis(arene) complex [K[2.2.2]cryptand][U(TDA)2] (3) (TDA = N-(2,6-di-isopropylphenyl)pivalamido). EPR spectroscopy, magnetic susceptibility measurements, and calculations using DFT as well as multireference CASSCF methods all provide strong evidence that the electronic structure of 3 is best represented as a 5f4 U(II) metal center bound to a monoreduced arene ligand. Reactivity studies show 3 reacts as a U(I) synthon by behaving as a two-electron reductant toward I2 to form the dinuclear U(III)-U(III) triiodide species [K[2.2.2]cryptand][(UI(TDA)2)2(μ-I)] (6) and as a three-electron reductant toward cycloheptatriene (CHT) to form the U(IV) complex [K[2.2.2]cryptand][U(η7-C7H7)(TDA)2(THF)] (7). The reaction of 3 with cyclooctatetraene (COT) generates a mixture of the U(III) anion [K[2.2.2]cryptand][U(TDA)4] (1-crypt) and U(COT)2, while the addition of COT to complex 2 instead yields the dinuclear U(IV)-U(IV) inverse sandwich complex [U(TDA)3]2(μ-η8:η3-C8H8) (8). Two-electron reduction of the homoleptic Th(IV) amidate complex Th(TDA)4 (4) with KC8 gives the mono(arene) complex [K[2.2.2]cryptand][Th(TDA)3(THF)] (5). The C-C bond lengths and torsion angles in the bound arene of 5 suggest a direduced arene bound to a Th(IV) metal center; this conclusion is supported by DFT calculations.
Collapse
Affiliation(s)
- Mark D Straub
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Erik T Ouellette
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Michael A Boreen
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - R David Britt
- Department of Chemistry, University of California─Davis, Davis, California 95616, United States
| | - Khetpakorn Chakarawet
- Department of Chemistry, University of California─Davis, Davis, California 95616, United States
| | - Iskander Douair
- Université de Toulouse et CNRS, INSA, UPS, UMR 5215, LPCNO 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Colin A Gould
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Laurent Maron
- Université de Toulouse et CNRS, INSA, UPS, UMR 5215, LPCNO 135 Avenue de Rangueil, 31077 Toulouse, France
| | - Iker Del Rosal
- Université de Toulouse et CNRS, INSA, UPS, UMR 5215, LPCNO 135 Avenue de Rangueil, 31077 Toulouse, France
| | - David Villarreal
- Department of Chemistry, University of California─Davis, Davis, California 95616, United States
| | - Stefan G Minasian
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - John Arnold
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| |
Collapse
|