Bis[1]benzothieno[1,4]thiaborins as a Platform for BODIPY Singlet Oxygen Photosensitizers

Marek‐Urban, Paulina H.; Urbanowicz, Karolina A.; Wrochna, Karolina; Pander, Piotr; Blacha‐Grzechnik, Agata; Hauer, Simone T.; Berens, Henning R. V.; Woźniak, Krzysztof; Müller, Thomas J. J.; Durka, Krzysztof

Abstract

A synthetic approach to two regioisomeric π-electron extended [1,4]thiaborins annulated with two benzothiophene units has been developed. The central thiaborin rings of the boracycles obtained exhibit different electronic properties; this is reflected in their different aromatic characters, boron Lewis acidity and UV-vis spectroscopic behavior. Thiaborins were converted to boron dipyrromethene (BODIPY) complexes. Their emission spectra exhibit two distinct bands resulting from 1LE and 1CT transitions. Strong near-infrared phosphorescence in Zeonex thin films at 77 K indicates efficient intersystem crossing and the formation of triplet states. Separation of HOMO and LUMO orbitals between boracyclic and BODIPY moieties facilitates electron transfer to a 1CT state followed by a transition to the 3LE triplet state located on the ligand. These unique properties of spiro thiaborin-BODIPY complexes were explored for their application as singlet-oxygen photosensitizers. They show excellent photocatalytic performance with singlet oxygen quantum yields reaching 77 % and full conversion of the model organic substrate achieved after 1.5 h with only 0.05 % mol catalyst load.

Citation

Marek‐Urban, P. H., Urbanowicz, K. A., Wrochna, K., Pander, P., Blacha‐Grzechnik, A., Hauer, S. T., …Durka, K. (2023). Bis[1]benzothieno[1,4]thiaborins as a Platform for BODIPY Singlet Oxygen Photosensitizers. Chemistry - A European Journal, 29(36), Article e202300680. https://doi.org/10.1002/chem.202300680

• Journal Article Type: Article
• Acceptance Date: Mar 28, 2023
• Online Publication Date: Mar 29, 2023
• Publication Date: Jun 27, 2023
• Deposit Date: Oct 10, 2023
• Publicly Available Date: Mar 30, 2024
• Journal: Chemistry – A European Journal
• Print ISSN: 0947-6539
• Electronic ISSN: 1521-3765
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 29
• Issue: 36
• Article Number: e202300680
• DOI: https://doi.org/10.1002/chem.202300680
• Public URL: https://durham-repository.worktribe.com/output/1788644