Deciphering the mechanism of O2 reduction with electronically tunable non-heme iron enzyme model complexes

Authors

Roshaan Surendhran, SUNY University at Buffalo
Alexander A. D'Arpino, SUNY University at Buffalo
Bao Y. Sciscent, SUNY University at Buffalo
Anthony F. Cannella, SUNY University at Buffalo
Alan E. Friedman, SUNY University at Buffalo
Samantha N. MacMillan, Cornell University
Rupal Gupta, CUNY College of Staten IslandFollow
David C. Lacy, SUNY University at Buffalo

Document Type

Article

Publication Date

6-5-2018

Abstract

A homologous series of electronically tuned 2,20,200-nitrilotris(N-arylacetamide) pre-ligands (H3LR) were prepared (R ¼ NO2, CN, CF3, F, Cl, Br, Et, Me, H, OMe, NMe2) and some of their corresponding Fe and Zn species synthesized. The iron complexes react rapidly with O2, the final products of which are diferric mu-oxo bridged species. The crystal structure of the oxidized product obtained from DMA solutions contain a structural motif found in some diiron proteins. The mechanism of iron mediated O2 reduction was explored to the extent that allowed us to construct an empirically consistent rate law. A Hammett plot was constructed that enabled insightful information into the rate-determining step and hence allows for a differentiation between two kinetically equivalent O2 reduction mechanisms.

Comments

This article was originally published in Chemical Science, available at DOI: 10.1039/c8sc01621f.

This is an open access article licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.