Three-coordinate copper(I) amido and aminyl radical complexes. J Am Chem Soc 2009 Mar 25;131(11):3878-80
Date
03/04/2009Pubmed ID
19253942Pubmed Central ID
PMC3110787DOI
10.1021/ja809834kScopus ID
2-s2.0-67849127122 (requires institutional sign-in at Scopus site) 100 CitationsAbstract
A three-coordinate Cu-NR(2) system (R = p-tolyl) supported by the anionic bis(phosphino)borate ligand [Ph(2)B(CH(2)P(t)Bu(2))(2)](-) has been isolated and structurally characterized in both its anionic Cu(I) and neutral (formally) Cu(II) oxidation states. A large rate constant for the self-exchange electron-transfer reaction (k(S) >or= 10(7) M(-1) s(-1)) makes this system a functional model for the type-1 active sites in blue copper proteins. Multiedge X-ray absorption spectroscopy, multifrequency electron paramagnetic resonance, and density functional theory analyses collectively indicate that the oxidized form is best regarded as a Cu(I)-aminyl radical complex rather than a Cu(II)-amido species, with about 70% localization of the unpaired electron on the NR(2) unit. Hydrogen-atom transfer and C-C coupling reactions are presented as examples of chemical reactivity manifested by this unusual electronic structure.
Author List
Mankad NP, Antholine WE, Szilagyi RK, Peters JCMESH terms used to index this publication - Major topics in bold
AmidesAmines
Copper
Electron Transport
Free Radicals
Kinetics
Metalloproteins
Models, Biological
Models, Chemical
Oxidation-Reduction
