Erlangen 2022 – scientific programme

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MO: Fachverband Molekülphysik

MO 8: Poster 1

MO 8.22: Poster

Tuesday, March 15, 2022, 16:30–18:30, P

Juxtaposition of the photolysis of diphenyldiselenide Ph₂Se₂ and diphenylselenide Ph₂Se and the subsequent recombination dynamics of the transient radicals — •Daniel Grenda¹, Carina Allacher¹, Elias Harrer¹, Roger Jan Kutta¹, Alexander Breder², and Patrick Nuernberger¹ — ¹Institut für Physikalische und Theoretische Chemie, Universität Regensburg, 93040 Regensburg — ²Institut für Organische Chemie, Universität Regensburg, 93040 Regensburg

Organoselenium compounds can be used as effective catalysts in organic synthesis [1], they are building up polymers with dynamic covalent bonds [2] and they are working as antioxidants in vivo [3]. This rich chemistry is possible by virtue of the low bond energy of selenium bonds [2] and recombination of selenium-centered radicals.
By transient absorption spectroscopy on a nano- to microsecond timescale, we follow the dynamics of Ph₂Se and Ph₂Se₂ after photodissociation of the carbon-selenium or the selenium-selenium bond, respectively, forming the radicals PhSe^• and Ph^•. Both species photodegrade over prolonged illumination and partially interconvert into each other due to bimolecular radical pair recombination. Comparison of the differences and analogies of the photochemistry of Ph₂Se₂ and Ph₂Se allows a specific identification of the entire reaction pathways, intermediates and products.
[1] J. Trenner et al., Angew. Chem. Int. Ed. 52, 8952 (2013).
[2] S. Ji et al., Angew. Chem. Int. Ed. 53, 6781 (2014).
[3] L. P. Borges et al., Chem.-Biol. Interact., 160, 99 (2006).