Anti-Kasha fluorescence and persistent room-temperature phosphorescence from a nearly flat non-symmetric polycyclic hydrocarbon
Abstract
Polycyclic aromatic hydrocarbons are molecular frameworks that enable the development of efficient emitters owing to their extensive conjugation and rigid structure. Here, we introduce monohomotruxene (MHTX), designed by reducing the symmetry of homotruxene (HTX) and truxene (TX). This partial planarization greatly enhances the complex photophysics over symmetric, triply twisted HTX, substantially increasing the photoluminescence quantum yield (PLQY), a result we attribute to its enhanced molecular rigidity and symmetry breaking. MHTX displays an unconventional violation of Kasha’s rule, yielding excitation-dependent dual emission. Excitation of the S ₂ state under anaerobic conditions produces intense, 455–480 nm, ultralong room-temperature phosphorescence (RTP), lasting over 12 s at room temperature. In contrast, excitation into the S ₁ state yields prompt fluorescence and weak delayed fluorescence (DF) by triplet-triplet annihilation (TTA) in the neat film. Aggregate species also present a complex emissive behavior with weak orange phosphorescence and TTA-DF. These findings establish MHTX as a promising emissive scaffold, highlighting the potential for accessing complex excited-state dynamics and advanced photophysical functionalities.
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BibTeX
@article{kutz2026antikasha,
title = {{Anti-Kasha fluorescence and persistent room-temperature phosphorescence from a nearly flat non-symmetric polycyclic hydrocarbon}},
author = {Monike da Silva Kutz and Carolina Francener and Wataru Ota and Manuela Santos Corrêa and Daniel Crane and Emiko Fujiwara and Tohru Sato and Ivan H. Bechtold and Andrew P. Monkman and Eduard Westphal and Harald Bock},
journal = {Nature Communications},
year = {2026},
month = oct,
doi = {10.1038/s41467-026-78107-6},
url = {https://www.nature.com/articles/s41467-026-78107-6},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Anti-Kasha fluorescence and persistent room-temperature phosphorescence from a nearly flat non-symmetric polycyclic hydrocarbon
AU - Monike da Silva Kutz
AU - Carolina Francener
AU - Wataru Ota
AU - Manuela Santos Corrêa
AU - Daniel Crane
AU - Emiko Fujiwara
AU - Tohru Sato
AU - Ivan H. Bechtold
AU - Andrew P. Monkman
AU - Eduard Westphal
AU - Harald Bock
PY - 2026
DA - 2026/10/02
JO - Nature Communications
DO - 10.1038/s41467-026-78107-6
UR - https://www.nature.com/articles/s41467-026-78107-6
AB - Polycyclic aromatic hydrocarbons are molecular frameworks that enable the development of efficient emitters owing to their extensive conjugation and rigid structure. Here, we introduce monohomotruxene (MHTX), designed by reducing the symmetry of homotruxene (HTX) and truxene (TX). This partial planarization greatly enhances the complex photophysics over symmetric, triply twisted HTX, substantially increasing the photoluminescence quantum yield (PLQY), a result we attribute to its enhanced molecular rigidity and symmetry breaking. MHTX displays an unconventional violation of Kasha’s rule, yielding excitation-dependent dual emission. Excitation of the S ₂ state under anaerobic conditions produces intense, 455–480 nm, ultralong room-temperature phosphorescence (RTP), lasting over 12 s at room temperature. In contrast, excitation into the S ₁ state yields prompt fluorescence and weak delayed fluorescence (DF) by triplet-triplet annihilation (TTA) in the neat film. Aggregate species also present a complex emissive behavior with weak orange phosphorescence and TTA-DF. These findings establish MHTX as a promising emissive scaffold, highlighting the potential for accessing complex excited-state dynamics and advanced photophysical functionalities.
SN - 2041-1723
ER -