Structural and spectroscopic characterization of a charge-separated uranium benzophenone ketyl radical complex.
The reaction of [((t-Bu)ArO) 3tacn)U (III)] ( 1) with 4,4'-di- tert-butylbenzophenone affords a unique isolable U(IV) ketyl radical species [((t-Bu)ArO) 3tacn)U (IV)(OC* (t-Bu)Ph 2)] (2) supported by XRD data, magnetization measurements, and DFT calculations. Isolation and full characterization of the corresponding diphenyl methoxide complex [((t-Bu)ArO) 3tacn)U (IV)(OCH ( t-Bu )Ph 2)] (3) is also presented. The one-electron reduction of benzophenone by [((Ad)ArO) 3tacn)U (III)] (4) leads to a purple U(IV) ketyl radical intermediate [((Ad)ArO) 3tacn)U (IV)(OC*Ph 2)] (5). This species is highly reactive, and attempts at isolation were unsuccessful and resulted in methoxide complex [((Ad)ArO) 3tacn)U (IV)(OCHPh 2)] (6) from H abstraction and dinuclear para-coupled complex [((Ad)ArO) 3tacn)U (IV)(OCPhPhCPh 2O)U (IV)((Ad)ArO) 3tacn)] (7).
Lam
Oanh P
OP
Department of Chemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
Anthon
Christian
C
Heinemann
Frank W
FW
O'Connor
Joseph M
JM
Meyer
Karsten
K
D001577:Benzophenones / Q000737:chemistry*; D005449:Fluorenes / Q000737:chemistry; D007659:Ketones / Q000737:chemistry; D008024:Ligands; D008280:Magnetics; D008958:Models, Molecular; D014501:Uranium / Q000737:chemistry*; D014961:X-Ray Diffraction
D001577:Benzophenones; D005449:Fluorenes; D007659:Ketones; D008024:Ligands; D014501:Uranium