Structural and spectroscopic characterization of a charge-separated uranium benzophenone ketyl radical complex

Oanh P Lam; Christian Anthon; Frank W Heinemann; Joseph M O'Connor; Karsten Meyer

doi:10.1021/ja801007q

Structural and spectroscopic characterization of a charge-separated uranium benzophenone ketyl radical complex

J Am Chem Soc. 2008 May 21;130(20):6567-76. doi: 10.1021/ja801007q. Epub 2008 Apr 26.

Authors

Oanh P Lam¹, Christian Anthon, Frank W Heinemann, Joseph M O'Connor, Karsten Meyer

Affiliation

¹ Department of Chemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.

PMID: 18439015
DOI: 10.1021/ja801007q

Abstract

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).

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Benzophenones / chemistry*
Fluorenes / chemistry
Ketones / chemistry
Ligands
Magnetics
Models, Molecular
Uranium / chemistry*
X-Ray Diffraction

Substances

Benzophenones
Fluorenes
Ketones
Ligands
Uranium