Freiburg 2024 – scientific programme

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MO: Fachverband Molekülphysik

MO 7: Poster: Spectroscopy

MO 7.9: Poster

Tuesday, March 12, 2024, 17:00–19:00, Tent C

Time-Resolved Spectroscopic Studies on the Net Heterolysis of Homopolar Selenium-Carbon Bonds — •Daniel Jan Grenda, Anna Franziska Tiefel, Carina Allacher, Elias Harrer, Roger Jan Kutta, Julia Rehbein, Alexander Breder, and Patrick Nuernberger — Universität Regensburg, 93040 Regensburg

When thinking about chemical bonds, one considers polarity as the major factor determining if a bond cleavage occurs homolytically or heterolytically, as bonds with a negligible dipole moment exclusively undergo homolysis, whereas heterolysis requires a sufficiently high dipole moment or some kind of external bond activation [1]. We demonstrate that by combining photochemistry [2] with the radical chemistry of organoselenium compounds [3] and the properties of the solvent hexafluoroisopropanol [3, 4], net heterolysis of the homopolar selenium-carbon bond can be achieved and utilized in a subsequent S_N1-type substitution. The mechanism of this reaction is disclosed using transient absorption spectroscopy with streak-camera detection [5] and other advanced spectroscopic techniques, as well as theoretical and synthetic investigations.

[1] H. Brueckner, Reaktionsmechanismen Springer Spektrum (2008).
[2] B. Koenig et al., Eur. J. Org. Chem., 15, 1979-1981 (2017).
[3] I. Colomer et al., Nat. Rev. Chem., 1, 0088 (2017).
[4] S. Park et al., Angew. Chem. Int. Ed., 61, e202208611 (2022).
[5] R. J. Kutta et al., Appl. Phys. B, 111, 203-216 (2013).

Keywords: Photochemistry; Spectroscopy; Synthesis; Theoretical Chemistry