5 years ago

On the Way to a Trisanionic {Cu3O2} Core for Oxidase Catalysis: Evidence of an Asymmetric Trinuclear Precursor Stabilized by Perfluoropinacolate Ligands

On the Way to a Trisanionic {Cu3O2} Core for Oxidase Catalysis: Evidence of an Asymmetric Trinuclear Precursor Stabilized by Perfluoropinacolate Ligands
Steven F. Hannigan, Nicole Orth, Arnold L. Rheingold, James A. Golen, Alexander Hoffmann, Ivana Ivanović-Burmazović, Thomas Rösener, Patricia Liebhäuser, June S. Lum, Linda H. Doerrer, Sarah E. Neville, Sonja Herres-Pawlis, Julia Stanek, Amanda I. Arnoff
CuI complexes of the form K[(R3P)Cu(pinF)], in which (pinF)2− is the bidentate, oxygen-donating ligand perfluoropinacolate, were synthesized and characterized. Low-temperature oxygenation of the K[(R3P)Cu(pinF)(PR3)] species resulted in a trisanionic bis(μ3-oxo) trinuclear copper(II,II,III) core characterized by UV/Vis spectroscopy (λmax [nm] = 330, 535, 630), cryospray-ionization mass spectrometry, and X-band electron paramagnetic resonance spectroscopy (derivative resonance at 3300 G, Δms=2 at 1500 G). The kinetic behavior of the trimeric {Cu3O2} species was quantified by stopped-flow spectroscopy and the associated electronic structures were investigated by DFT calculations. An asymmetric {Cu3O2} species, AsTpinF, which bears a structure similar to multicopper oxidases, forms prior to full formation of the symmetric trinuclear core, SyTpinF. The trimer catalytically oxidizes para-hydroquinone to benzoquinone (a form of oxidase chemistry). Three is a magic number: A trinuclear {Cu-O2} species stabilised by dianionic ligands has been characterised by UV/Vis stopped-flow spectroscopy in solution. A bis(μ-oxo) dicopper core forms initially, followed by an asymmetric trinuclear species that converts to a symmetric one as the final oxygenation product. For the first time, this rare biorelated, asymmetric species could be stabilised using perfluoropinacolate dianionic ligands. The trinuclear core is a functional model for the active site of multi-copper oxidases. DFT calculations yielded further insights into the electronic structure and catalytic hydroquinone oxidation proves the oxidase capability of the symmetric trinuclear core.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/chem.201605926

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.