Reduction of (pddi)Cr reveals redox noninnocence via C-C bond formation amidst competing electrophilicity: [(cpta)CrMen]- (n = 0, 1) and [(pta)Cr].

Reversible cyclopropane formation is probed as a means of redox noninnocence in diimine/diamide chelates via reduction and complex anion formation. Competition from imine attack renders complications in the latter approach, and electrochemical measurements with calculational support provide the rationale.

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

A homologous series of electronically tuned 2,2',2''-nitrilotris(N-arylacetamide) pre-ligands (H3LR ) were prepared (R = 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.