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

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.

SUBMITTER: Farias G

PROVIDER: S-EPMC8612374 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature

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

Farias Giliandro G Salla Cristian A M CAM Aydemir Murat M Sturm Ludmilla L Dechambenoit Pierre P Durola Fabien F de Souza Bernardo B Bock Harald H Monkman Andrew P AP Bechtold Ivan H IH

Chemical science 20211101 45

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 configuratio ...[more]

PMID: 34909153

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