Room Temperature Phosphorescence in Solution from Thiophene-Bridged Triply Donor-Substituted Tristriazolotriazines

Hugo Marchi Luciano; Giliandro Farias; Cristian M Salla; Larissa G Franca; Suman Kuila; Andrew P Monkman; Fabien Durola; Ivan H Bechtold; Harald Bock; Hugo Gallardo

doi:10.1002/chem.202203800

Room Temperature Phosphorescence in Solution from Thiophene-Bridged Triply Donor-Substituted Tristriazolotriazines

Chemistry. 2023 Apr 21;29(23):e202203800. doi: 10.1002/chem.202203800. Epub 2023 Mar 15.

Authors

Affiliations

¹ Departamento de Química, Universidade Federal de Santa Catarina Trindade, 88040-900, Florianópolis, SC, Brazil.
² Centre de Recherche Paul Pascal, Université Bordeaux, 115 av. Schweitzer, 33600, Pessac, France.
³ Departamento de Física, Universidade Federal de Santa Catarina Trindade, 88040-900, Florianópolis, SC, Brazil.
⁴ Department of Physics, Durham University, Durham, DH1 3LE, UK.
⁵ Centre de Recherche Paul Pascal, CNRS, 115 av. Schweitzer, 33600, Pessac, France.

PMID: 36648938
DOI: 10.1002/chem.202203800

Abstract

Most organic room-temperature phosphorescence (RTP) emitters do not show their RTP in solution. Here, we incorporated sulfur-containing thiophene bridges between the donor and acceptor moieties in D₃ A-type tristriazolotriazines (TTTs). The thiophene inclusion increased the spin-orbit coupling associated with the radiative T₁ →S₀ pathway, allowing RTP to be observed in solution for all compounds, likely assisted by protection of the emissive TTT-thiophene core from the environment by the bulky peripheral donors.

Keywords: delayed fluorescence; heavy atom effect; phosphorescence; room temperature tristriazolotriazine.