title: Copolymerization of 2,4-dichlorophenol with humic substances by oxidative and photo-oxidative biomimetic catalysis.
abstract: We evaluated the catalytic activity of a water-soluble iron-porphyrin in an oxidative coupling reaction to form covalent bonds between 2,4-dichlorophenol (2,4-DCP) and humic molecules. The biomimetic catalysis in the presence of H₂O₂ was tested in the dark and in daylight, and changes in reaction products were revealed by high-performance liquid chromatography (HPLC) and nuclear magnetic resonance (NMR) spectroscopy. In all conditions, iron-porphyrin was effective in promoting complete disappearance of 2,4-DCP, although catalyst activity was enhanced in daylight (with a maximum turnover number of 85.13). Further evidence of the occurred covalent coupling between 2,4-DCP and humic molecules was revealed by diffusion-ordered nuclear magnetic resonance (DOSY-NMR) spectroscopy that showed a reduced diffusivity of 2,4-DCP after the catalytic reaction. These findings indicate that iron-porphyrin is an efficient catalyst for the covalent binding of polyhalogenated phenols to humic molecules, thereby suggesting that the copolymerization reactions may become a useful technology to remediate soils and waters contaminated by halogenated phenols and their analogues.
authors.forename: Barbara
authors.initials: B
authors.lastname: Fontaine
authors.forename: Marios
authors.initials: M
authors.lastname: Drosos
authors.forename: Pierluigi
authors.initials: P
authors.lastname: Mazzei
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D002384:Catalysis; D002733:Chlorophenols / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D052918:Environmental Restoration and Remediation / Q000379:methods*; D006812:Humic Substances / Q000032:analysis*; D006861:Hydrogen Peroxide / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008665:Metalloporphyrins / Q000737:chemistry*; D058105:Polymerization
chemical_list: D002733:Chlorophenols; D006812:Humic Substances; D008665:Metalloporphyrins; C035807:ferroporphyrin; D006861:Hydrogen Peroxide; C004762:2,4-dichlorophenol