Earth Abundant Oxidation Catalysts for Removal of Contaminants of Emerging Concern from Wastewater: Homogeneous Catalytic Screening of Monomeric Complexes

Garcia, Leslie; Koper, Makynna R.; Mondal, Somrita; Priddle, Joshua T.; Truong, William A.; Allbritton, Elisabeth M. A.; McAdoo, Ashtyn G.; Cannon-Smith, Desiray J.; Funwie, Neil L.; Hoang, Tuyet; Kim, Inseo; Hubin, David J.; Krause, Jeanette A.; Oliver, Allen G.; Prior, Timothy J.; Hubin, Timothy J.

Abstract

Twenty novel Mn, Fe, and Cu complexes of ethylene cross-bridged tetraazamacrocycles with potentially copolymerizable allyl and benzyl pendant arms were synthesized and characterized. Multiple X-ray crystal structures demonstrate the cis-folded pseudo-octahedral geometry forced by the rigidifying ethylene cross-bridge and show that two cis coordination cites are available for interaction with substrate and oxidant. The Cu complexes were used to determine kinetic stability under harsh acidic and high-temperature conditions, which revealed that the cyclam-based ligands provide superior stabilization with half-lives of many minutes or even hours in 5 M HCl at 50–90 °C. Cyclic voltammetry studies of the Fe and Mn complexes reveal reversible redox processes indicating stabilization of Fe2+/Fe3+ and Mn2+/Mn3+/Mn4+ oxidation states, indicating the likelihood of catalytic oxidation for these complexes. Finally, dye-bleaching experiments with methylene blue, methyl orange, and rhodamine B demonstrate efficient catalytic decolorization and allow selection of the most successful monomeric catalysts for copolymerization to produce future heterogeneous water purification materials.

Citation

Garcia, L., Koper, M. R., Mondal, S., Priddle, J. T., Truong, W. A., Allbritton, E. M. A., …Hubin, T. J. (2023). Earth Abundant Oxidation Catalysts for Removal of Contaminants of Emerging Concern from Wastewater: Homogeneous Catalytic Screening of Monomeric Complexes. Molecules, 28(18), 6466. https://doi.org/10.3390/molecules28186466

• Journal Article Type: Article
• Acceptance Date: Sep 4, 2023
• Online Publication Date: Sep 6, 2023
• Publication Date: Sep 1, 2023
• Deposit Date: Dec 20, 2023
• Publicly Available Date: Dec 21, 2023
• Journal: Molecules
• Electronic ISSN: 1420-3049
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 28
• Issue: 18
• Pages: 6466
• DOI: https://doi.org/10.3390/molecules28186466
• Keywords: Chemistry (miscellaneous); Analytical Chemistry; Organic Chemistry; Physical and Theoretical Chemistry; Molecular Medicine; Drug Discovery; Pharmaceutical Science
• Public URL: https://hull-repository.worktribe.com/output/4386212