Abstract
Photochemical oxidation of dissolved organic matter is a crucial component of carbon cycling in surface waters. Photo-oxidation of iron(III)-carboxylate complexes is of particular interest because complexation with iron(III) can sensitize this functional group to photodecarboxylation. The photo-oxidation mechanism of ferrioxalate has been extensively characterized, but it is unclear whether the mechanism or timing is similar for other more complex carboxylates. In this study, we use time-resolved infrared spectroscopy to demonstrate that Fe(III)-citrate, an aliphatic carboxylate, and Fe(III)-salicylate, an aromatic carboxylate, follow the same photo-oxidation kinetics as ferrioxalate. Hence the data suggest a common mechanism for decarboxylation of iron hydroxy carbonates. Differences in the CO2 yield within 50 ps are qualitatively similar to the long-time-scale quantum yield for Fe(II) production.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 6186-6190 |
| Number of pages | 5 |
| Journal | Journal of Physical Chemistry A |
| Volume | 127 |
| Issue number | 30 |
| DOIs | |
| State | Published - Aug 3 2023 |
Funding
C.J.W. was supported by an NSF Postdoctoral Fellowship from the Division of Earth Sciences under Award # 1854875. B.G. was supported by the Chemical Sciences, Geosciences, and Biosciences Division, of the U.S. Department of Energy (DOE) under Contract No. DE-AC02-05CH11231. R.D.S. and use of the Center for Nanoscale Materials, an Office of Science user facility, were supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry