ETH, Switzerland

Kris McNeill received his B.A. in Chemistry from Reed College in Portland, OR, USA in 1992 and his Ph.D. in Chemistry from the University of California, Berkeley in 1997. At Berkeley, he was co-advised by...

Professors Robert Bergman and Richard Andersen. Following his PhD, he did postdoctoral research at MIT from 1997 to 1999 with Prof. Philip Gschwend in the department of Civil and Environmental Engineering, he began his independent career as a faculty member at the University of Minnesota in the Department of Chemistry, holding ranks of Assistant Professor (2000-2006) and Associate Professor (2007-2009). In 2009, he joined the faculty of ETH Zurich as Professor of Environmental Chemistry.

 

Abstract


Triplet excited state organic matter and the photochemical degradation of persistent and toxic substances

Kristopher McNeill1, *

1 ETH Zurich, Institute of Biogeochemistry and Pollutant Dynamics, Universitaetstrasse 16, 8092 Zurich, This email address is being protected from spambots. You need JavaScript enabled to view it.

Triplet excited states of dissolved organic matter are important intermediates in the photochemistry of natural waters. They are strong oxidants that are central to many transformation reactions involved in the degradation of persistent and toxic substances. Additionally, these triplet states are the precursors for many other reactive species, including singlet oxygen, superoxide, hydrogen peroxide and hydroxyl radical. The study of these triplet states is made difficult by the fact that the they are not a single species, but a complex mixture of many chemical species. Recent work in our laboratory has focused on laser spectrscopy-based strategies that simplify the complex signal mixture arising from triplet states to yield information their reaction kinetics, oxidation potentials and triplet energies. This presentation will summarize recent progress in these efforts.


 

McNeill K, Canonica S. Triplet state dissolved organic matter in aquatic photochemistry: reaction mechanisms, substrate scope, and photophysical properties. Environmental Science: Processes & Impacts 2016, 18, 1381-99.
Wenk J, Eustis SN, McNeill K, Canonica S. Quenching of excited triplet states by dissolved natural organic matter. Environmental Science & Technology 2013, 47, 12802-10.
Erickson PR, Moor KJ, Werner JJ, Latch DE, Arnold WA, McNeill K. Singlet Oxygen Phosphorescence as a Probe for Triplet-State Dissolved Organic Matter Reactivity. Environmental Science & Technology 2018, 52, 9170-8.
Schmitt M, Erickson PR, McNeill K. Triplet-state dissolved organic matter quantum yields and lifetimes from direct observation of aromatic amine oxidation. Environmental Science & Technology 2017, 51, 13151-60.