Iron Porphyrazines as Sustainable Catalysts of Rapid Chlorite Dismutation

Abstract

Chlorine dioxide is a powerful, selective oxidant with a range of applications that exploit its efficacy as a biocide and a bleach. However, current industrial methods of production are plagued by hazardous conditions, inefficiencies, and toxic waste. In recent years, several catalysts of chlorite dismutation to chlorine dioxide have been developed; however these complexes require extended time to conduct this conversion and suffer from deterioration. In this thesis, several iron porphyrazines were found to catalyze chlorite dismutation. In particular, the water-soluble iron (II) tetra-N-methyl-2,3-pyridinoporphyrazine (FeTM23PyPz) rapidly produced chlorine dioxide at a rate second only to its highly unstable manganese-based analog, MnTM23PyPz. In addition to fast catalytic rates, FeTM23PyPz is unparalleled in its durability, as this porphyrazine was capable of sustaining reactivity for at least 10 times as many turnovers as currently known catalysts before degradation. The distribution of all known oxygen- and chlorine-containing products of chlorite dismutation catalyzed by these iron porphyrazines was also determined, unveiling several potential future methods to further optimize chlorine dioxide generation catalyzed by FeTM23PyPz. Ultimately, the results presented in this thesis demonstrate that FeTM23PyPz is a candidate catalyst for rapid and sustainable chlorine production on a large scale.