Interfacial Oxidative Oligomerization of Catechol.

Authors

Marcelo I. Guzman, University of Kentucky
Elizabeth A. Pillar-Little, University of Kentucky
Alexis J. Eugene, University of Kentucky

Abstract

The heterogeneous reaction between thin films of catechol exposed to O₃(g) creates hydroxyl radicals (HO^•) in situ, which in turn generate semiquinone radical intermediates in the path to form heavier polyhydroxylated biphenyl, terphenyl, and triphenylene products. Herein, the alteration of catechol aromatic surfaces and their chemical composition are studied during the heterogeneous oxidation of catechol films by O₃(g) molar ratios ≥ 230 ppbv at variable relative humidity levels (0% ≤ RH ≤ 90%). Fourier transform infrared micro-spectroscopy, atomic force microscopy, electrospray ionization mass spectrometry, and reverse-phase liquid chromatography with UV–visible and mass spectrometry detection provide new physical insights into understanding the surface reaction. A Langmuir–Hinshelwood mechanism is accounted to report reaction rates, half-lives, and reactive uptake coefficients for the system under variable relative humidity levels. The reactions reported explain how the oligomerization of polyphenols proceeds at interfaces to contribute to the formation of brown organic carbon in atmospheric aerosols.

Document Type

Article

Publication Date

9-22-2022

Notes/Citation Information

Published in ACS Omega, 2022, v. 7, no. 40, p. 36009–36016

Digital Object Identifier (DOI)

10.1021/acsomega.2c05290

Funding Information

Support from the U.S. National Science Foundation under Award 1903744 to M.I.G. is gratefully acknowledged.

Repository Citation

Guzman, Marcelo I.; Pillar-Little, Elizabeth A.; and Eugene, Alexis J., "Interfacial Oxidative Oligomerization of Catechol." (2022). Chemistry Faculty Publications. 196.
https://uknowledge.uky.edu/chemistry_facpub/196