Computational Design and Synthesis of a Deeply Red-Shifted and Bistable Azobenzene

Konrad, David B.; Savasci, Gökcen; Allmendinger, Lars; Trauner, Dirk; Ochsenfeld, Christian und Ali, Ahmed M. (2020): Computational Design and Synthesis of a Deeply Red-Shifted and Bistable Azobenzene. In: Journal of the American Chemical Society, Bd. 142, Nr. 14: S. 6538-6547

Abstract

We computationally dissected the electronic and geometrical influences of ortho-chlorinated azobenzenes on their photophysical properties. X-ray analysis provided the insight that trans-tetra-ortho-chloro azobenzene is conformationally flexible and thus subject to molecular motions. This allows the photoswitch to adopt a range of red-shifted geometries, which account for the extended n → π* band tails. On the basis of our results, we designed the di-ortho-fluoro di-ortho-chloro (dfdc) azobenzene and provided computational evidence for the superiority of this substitution pattern to tetra-ortho-chloro azobenzene. Thereafter, we synthesized dfdc azobenzene by ortho-chlorination via 2-fold C–H activation and experimentally confirmed its structural and photophysical properties through UV–vis, NMR, and X-ray analyses. The advantages include near-bistable isomers and an increased separation of the n → π* bands between the trans- and cis-conformations, which allows for the generation of unusually high levels of the cis-isomer by irradiation with green/yellow light as well as red light within the biooptical window.

• Dokumententyp: Zeitschriftenartikel
• EU Funded Grant Agreement Number: 765739
• EU-Projekte: Horizon 2020 > Marie Skłodowska Curie Actions > Marie Skłodowska-Curie Innovative Training Networks > 765739: COSINE - Training network for COmputational Spectroscopy In Natural sciences and Engineering
• Fakultät: Chemie und Pharmazie > Department Chemie
• Themengebiete: 500 Naturwissenschaften und Mathematik > 540 Chemie
• ISSN: 0002-7863
• Sprache: Englisch