Halogenation of a twisted non-polar π-system as a tool to modulate phosphorescence at room temperature

Farias, Giliandro; Salla, Cristian A.M.; Aydemir, Murat; Sturm, Ludmilla; Dechambenoit, Pierre; Durola, Fabien; de Souza, Bernardo; Bock, Harald; Monkman, Andrew P.; Bechtold, Ivan H.

Abstract

Halogenation of a twisted three-fold symmetric hydrocarbon with F, Cl or Br leads to strong modulation of triplet–triplet annihilation and dual phosphorescence, one thermally activated and the other very persistent and visible by eye, with different relative contributions depending on the halide. The room temperature phosphorescence is highly unusual given the absence of lone-pair-contributing heteroatoms. The interplay between the spin–orbit coupling matrix elements and the spatial configuration of the triplet state induces efficient intersystem crossing and thus room temperature phosphorescence even without relying on heteroatomic electron lone pairs. A ninefold increase of the ISC rate after introduction of three bromine atoms is accompanied by a much higher 34-fold increase of phosphorescence rate.

Citation

Farias, G., Salla, C. A., Aydemir, M., Sturm, L., Dechambenoit, P., Durola, F., …Bechtold, I. H. (2021). Halogenation of a twisted non-polar π-system as a tool to modulate phosphorescence at room temperature. Chemical Science, 12(45), https://doi.org/10.1039/d1sc04936d

• Journal Article Type: Article
• Acceptance Date: Oct 28, 2021
• Online Publication Date: Nov 1, 2021
• Publication Date: 2021
• Deposit Date: Feb 1, 2022
• Publicly Available Date: Feb 1, 2022
• Journal: Chemical Science
• Print ISSN: 2041-6520
• Electronic ISSN: 2041-6539
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 45
• DOI: https://doi.org/10.1039/d1sc04936d