Seminar: Oxidation, Reduction and Radical Chemistry in Plastics and People (Professor Steve Bottle )

Thursday, 12 September 2019 - 12:00pm – Thursday, 12 September 2019 - 1:00pm  |  ChemSci M11

Abstract

Nitroxides are highly versatile EPR probes, powerful antioxidants and very efficient
scavengers of free radicals. They play critically important roles in the stabilization of
polymers to prevent degradation. Significantly, when the nitroxide group is combined with a
conjugated fluorophore, excited state quenching and energy transfer essentially short-circuits
the usual fluorescence emission. When the nitroxide reacts, the natural fluorescent nature of
the conjugated systems returns which allows the monitoring of radical reactions by the level
of fluorescence detected. Nitroxides are also remarkable in that they can be both oxidised (to
the oxoammonium ion) or reduced (to the hydroxylamine). When incorporated within
polymers, nitroxides can provide important electroactive components in organic radical
batteries (ORB).1 The redox chemistry of nitroxides also forms the basis of new
developments in redox flow batteries,2,3 as new fluorescent probes for radicals and as
catalytic antioxidants in biological systems.4,5

This presentation will describe the synthesis, fluorescence and electrochemical properties of
some novel nitroxides, as well as some related analogues and derivatives. Of particular
interest is the oxidation of a novel catechol-based nitroxide and the non-radical
methoxyamine which may prove to have value as a biological antioxidant, or as a charge
carrier in redox flow batteries and other electro-active materials.


References
[1] W. Xiaoliang, W. Xu, M., V. Sprenkle, and W. Wang et al., Adv. Mater. 26, (2014), 7649–7653.
[2] T. Janoschka, N. Martin, M.D. Hager and U.S. Schubert et al., Nature, 527 (2015), 78-81.
[3] K-A. Hansen, J. Nerkar, K. Thomas, S.E. Bottle, A.P. O’Mullane, P.C. Talbot and J.P. Blinco, ACS Applied
Materials & Interfaces (2018), 10 (9), 7982–7988.
[4] K-L. Chong, B.A. Chalmers, J.K. Cullen, A. Kaur, J.L. Kolanowskic, B.J. Morrow, K.E. Fairfull-Smith,
M.J. Lavin, N.L. Barnett, E.J. New M.P. Murphy, S.E. Bottle, Free Radical Biology and Medicine (2018), 128
97-110.
[5] J. Blinco, K.E. Fairfull-Smith, B.J. Morrow, S.E. Bottle, Australian Journal of Chemistry 64 (2011), 373-
389.

Bio Sketch
Professor Steven Bottle is a graduate of the University of Queensland where he did an
Honours degree in medicinal chemistry. After working in various jobs in the pharmaceutical
and mining industry, he undertook a PhD at Griffith University and then an Alexander von
Humboldt Fellowship in Wuerzburg, Germany. On his return to Australia he took up an
academic position at QUT where he has risen to the rank of full professor. Professor Bottle
has held various roles at QUT including Research Director for the School and for the Faculty,
as well as leading QUT’s contribution to the CRC for Polymers and the ARC Centre of
Excellence for Free Radical Chemistry and Biotechnology. Professor Bottle is the co-author
of a popular textbook, a member of the ARC College of Experts and is currently the
President-Elect of the Royal Australian Chemical Institute. His research interests include the
broad chemistry of free radicals, especially in regards to the use of nitroxides in synthesis,
polymers, as analytical tools and as antioxidant drugs.