Structural, Mechanistic, and Ultradilute Catalysis Portrayal of Substrate Inhibition in the TAML-Hydrogen Peroxide Catalytic Oxidation of the Persistent Drug and Micropollutant, Propranolol.

TAML activators enable unprecedented, rapid, ultradilute oxidation catalysis where substrate inhibitions might seem improbable. Nevertheless, while TAML/HO rapidly degrades the drug propranolol, a micropollutant (MP) of broad concern, propranolol is shown to inhibit its own destruction under concentration conditions amenable to kinetics studies ([propranolol] = 50 μM). Substrate inhibition manifests as a decrease in the second-order rate constant k for HO oxidation of the resting Fe-TAML (RC) to the activated catalyst (AC), while the second-order rate constant k for attack of AC on propranolol is unaffected.

Homogeneous Catalysis Under Ultradilute Conditions: TAML/NaClO Oxidation of Persistent Metaldehyde.

TAML activators enable homogeneous oxidation catalysis where the catalyst and substrate (S) are ultradilute (pM-low μM) and the oxidant is very dilute (high nM-low mM). Water contamination by exceptionally persistent micropollutants (MPs), including metaldehyde (Met), provides an ideal space for determining the characteristics and utilitarian limits of this ultradilute catalysis. The low MP concentrations decrease throughout catalysis with S oxidation (k) and catalyst inactivation (k) competing for the active catalyst.

TAML/H2O2 Oxidative Degradation of Metaldehyde: Pursuing Better Water Treatment for the Most Persistent Pollutants.

The extremely persistent molluscicide, metaldehyde, widely used on farms and gardens, is often detected in drinking water sources of various countries at concentrations of regulatory concern. Metaldehyde contamination restricts treatment options. Conventional technologies for remediating dilute organics in drinking water, activated carbon, and ozone, are insufficiently effective against metaldehyde.

Activation of Dioxygen by a TAML Activator in Reverse Micelles: Characterization of an Fe(III)Fe(IV) Dimer and Associated Catalytic Chemistry.

Iron TAML activators of peroxides are functional catalase-peroxidase mimics. Switching from hydrogen peroxide (H2O2) to dioxygen (O2) as the primary oxidant was achieved by using a system of reverse micelles of Aerosol OT (AOT) in n-octane. Hydrophilic TAML activators are localized in the aqueous microreactors of reverse micelles where water is present in much lower abundance than in bulk water.