Chemical Reactions Involving Species with Unpaired Electrons
Georg Gescheidt
Institute of Physical and Theoretical Chemistry,
Graz University of Technology,
Stremayrgasse 9, 8010 Graz, Austria
Quite a number of chemical reactions proceed via intermediates with unpaired
electrons. To obtain insight into the mechanisms of such reactions, we have been
performing investigations comprising (para)magnetic-resonance spectroscopy (timeresolved EPR, NMR/CIDNP), laser-flash photolysis, and theoretical calculations.
In this lecture, I will present an overview on our work. I will report on initial stages in
photo-induced radical polymerization and end-group conversion in photopolymers.
Moreover I will show examples on our work on antioxidants, particularly polyphenols.
Finally, I will present examples from our work on Cu(II)-catalyzed Diels-Alder
reactions indicating structural features of intermediates.
References
(1)
Geier, R.; Wappl, C.; Freiszmuth, H.; Slugovc, C.; Gescheidt, G., Thermal
effects in polymerisations - a live view differentiating between bulk effects, thermal
diffusion, and oxygen inhibition. Polymer Chem. 2015, 6 (13), 2488-2492
(2)
Bellinazzi, M.; Batchelor, S. N.; Gescheidt, G., Probing Radical Chemistry in
Salmonella typhimurium Cells Under Oxidative Stress Using Spin Traps and Nitroxyl
Radicals. Appl. Magn. Reson. 2015, 46 (3), 239-24910.1007/s00723-014-0631-6.
(3)
Zalibera, M.; Stebe, P.-N.; Dietliker, K.; Gruetzmacher, H.; Spichty, M.;
Gescheidt, G., The Redox Chemistry of Mono- and Bis(acyl)phosphane Oxides. Eur.
J. Org. Chem. 2014, (2), 331-337
(4)
Umamaheswari, V.; Cias, P.; Poeppl, A.; Kaupp, M.; Gescheidt, G., Ligand
spheres in asymmetric hetero Diels-Alder reactions catalyzed by Cu(II) box
complexes: experiment and modeling. Dalton Trans. 2014, 43 (2), 698-705
(5)
Neshchadin, D.; Batchelor, S. N.; Bilkis, I.; Gescheidt, G., Short-lived
Phenoxyl Radicals Formed from Green-Tea Polyphenols and Highly Reactive
Oxygen Species: An Investigation by Time-Resolved EPR Spectroscopy. Angew.
Chem. Int. Ed. 2014, 53 (48), 13288-1329210.1002/anie.201407995.
(6)
Zalibera, M.; Nesvadba, P.; Gescheidt, G., Reaction of Benzopinacol with
Non-ionic Bases: Reversing the Pinacol Coupling. Org. Lett. 2013, 15 (18), 4627462910.1021/ol402253s.
(7)
Neshchadin, D.; Rosspeintner, A.; Griesser, M.; Lang, B.; MosqueraVazquez, S.; Vauthey, E.; Gorelik, V.; Liska, R.; Hametner, C.; Ganster, B.; Saf, R.;
Moszner, N.; Gescheidt, G., Acylgermanes: Photoinitiators and Sources for GeCentered Radicals. Insights into their Reactivity. J. Am. Chem. Soc. 2013, 135 (46),
17314-17321
(8)
Neshchadin, D.; Palumbo, F.; Sinicropi, M. S.; Andreu, I.; Gescheidt, G.;
Miranda, M. A., Topological control in radical reactions of cholesterol in model dyads.
Chem. Sci. 2013, 4 (4), 1608-1614