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Highly emissive excitons with reduced exchange energy in thermally activated delayed fluorescent molecules.

ABSTRACT: Unlike conventional thermally activated delayed fluorescence chromophores, boron-centered azatriangulene-like molecules combine a small excited-state singlet-triplet energy gap with high oscillator strengths and minor reorganization energies. Here, using highly correlated quantum-chemical calculations, we report this is driven by short-range reorganization of the electron density taking place upon electronic excitation of these multi-resonant structures. Based on this finding, we design a series of ?-extended boron- and nitrogen-doped nanographenes as promising candidates for efficient thermally activated delayed fluorescence emitters with concomitantly decreased singlet-triplet energy gaps, improved oscillator strengths and core rigidity compared to previously reported structures, permitting both emission color purity and tunability across the visible spectrum.

SUBMITTER: Pershin A

PROVIDER: S-EPMC6363735 | biostudies-literature | 2019 Feb

REPOSITORIES: biostudies-literature

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Highly emissive excitons with reduced exchange energy in thermally activated delayed fluorescent molecules.

Pershin Anton A Hall David D Lemaur Vincent V Sancho-Garcia Juan-Carlos JC Muccioli Luca L Zysman-Colman Eli E Beljonne David D Olivier Yoann Y

Nature communications 20190205 1

Unlike conventional thermally activated delayed fluorescence chromophores, boron-centered azatriangulene-like molecules combine a small excited-state singlet-triplet energy gap with high oscillator strengths and minor reorganization energies. Here, using highly correlated quantum-chemical calculations, we report this is driven by short-range reorganization of the electron density taking place upon electronic excitation of these multi-resonant structures. Based on this finding, we design a series ...[more]

PMID: 30723203

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