Dissemin is shutting down on January 1st, 2025

Published in

Royal Society of Chemistry, Physical Chemistry Chemical Physics, 9(18), p. 6430-6440

DOI: 10.1039/c5cp05009j

Links

Tools

Export citation

Search in Google Scholar

Donor-driven conformational flexibility in a real-life catalytic dicopper(ii) peroxo complex

Journal article published in 2016 by A. Hoffmann, S. Herres-Pawlis ORCID
This paper is available in a repository.
This paper is available in a repository.

Full text: Download

Green circle
Preprint: archiving allowed
Orange circle
Postprint: archiving restricted
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

The conformers of the real-life tyrosinase model [Cu2O2{HC(3-tBuPz)2(Py)}2](2+) which displays catalytic hydroxylation reactivity were investigated by density functional theory (DFT) studies including second-order perturbation theory and charge decomposition analysis (CDA). We elucidated the donor competition between pyrazolyl and pyridinyl moieties and found that pyrazolyl units are the stronger donors in bis(pyrazolyl)pyridinylmethane copper complexes. Geometry optimisations and TD-DFT calculations on all conformers proved to be robust in the prediction of the experimental data: the XAS distances and both charge-transfer bands are well reproduced. The CDA analyses gave insights into the electronic structure of the real-life peroxo dicopper species. The donor interplay as well as the multitude of interactions within two prototypical conformers have now been dissected in detail for the first time for a catalytic real-life system without simplifications. We find that the N donor interactions to the core are extremely stabilising and that in the conformer with both pyrazolyl units in equatorial position, these interactions are more stabilising than the axial ones. In the conformer with pyridinyl/pyrazolyl equator, the picture is more mixed but the general trend keeps consistent. We relate the extraordinary catalytic activity of the [Cu2O2{HC(3-tBuPz)2(Py)}2](2+) system to the subtle interplay of the different donor moieties.