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.
Surendhran, Roshaan; D'Arpino, Alexander A.; Sciscent, Bao Y.; Cannella, Anthony F.; Friedman, Alan E.; MacMillan, Samantha N.; Gupta, Rupal; and Lacy, David C., "Deciphering the mechanism of O2 reduction with electronically tunable non-heme iron enzyme model complexes" (2018). CUNY Academic Works.