Metal‐free organic triplet emitters are an emerging class of organic semiconducting material. Among them, molecules with tunable emission responsive to environmental stimuli have shown great potential in solid‐state lighting, sensors, and anti‐counterfeiting systems. Here, a novel excited‐state intramolecular proton transfer (ESIPT) system is proposed showing the activation of thermally activated delayed fluorescence (TADF) or room‐temperature phosphorescence (RTP) simultaneously from both keto and enol tautomers. The prototype ESIPT triplet emitters exhibit up to 50% delayed emission quantum yield. Their enol–keto tautomerization can be switched by controlling the matrix acidity in doped polymer films. Taking advantage of these unique properties, “on‐off” switchable triplet emission systems controlled by acid vapor annealing, as well as photopatterning systems capable of generating facile and high‐contrast emissive patterns, are devised.
- Award ID(s):
- 1800187
- NSF-PAR ID:
- 10289356
- Date Published:
- Journal Name:
- Chemical Science
- Volume:
- 12
- Issue:
- 1
- ISSN:
- 2041-6520
- Page Range / eLocation ID:
- 188 to 195
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Ultralong afterglow emissions due to room‐temperature phosphorescence (RTP) are of paramount importance in the advancement of smart sensors, bioimaging and light‐emitting devices. We herein present an efficient approach to achieve rarely accessible phosphorescence of heavy atom‐free organoboranes via photochemical switching of sterically tunable fluorescent Lewis pairs (LPs). LPs are widely applied in and well‐known for their outstanding performance in catalysis and supramolecular soft materials but have not thus far been exploited to develop photo‐responsive RTP materials. The intramolecular LP
M1BNM not only shows a dynamic response to thermal treatment due to reversible N→B coordination but crystals ofM1BNM also undergo rapid photochromic switching. As a result, unusual emission switching from short‐lived fluorescence to long‐lived phosphorescence (rad ‐M1BNM ,τ RTP=232 ms) is observed. The reported discoveries in the field of Lewis pairs chemistry offer important insights into their structural dynamics, while also pointing to new opportunities for photoactive materials with implications for fast responsive detectors. -
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Abstract Ultralong afterglow emissions due to room‐temperature phosphorescence (RTP) are of paramount importance in the advancement of smart sensors, bioimaging and light‐emitting devices. We herein present an efficient approach to achieve rarely accessible phosphorescence of heavy atom‐free organoboranes via photochemical switching of sterically tunable fluorescent Lewis pairs (LPs). LPs are widely applied in and well‐known for their outstanding performance in catalysis and supramolecular soft materials but have not thus far been exploited to develop photo‐responsive RTP materials. The intramolecular LP
M1BNM not only shows a dynamic response to thermal treatment due to reversible N→B coordination but crystals ofM1BNM also undergo rapid photochromic switching. As a result, unusual emission switching from short‐lived fluorescence to long‐lived phosphorescence (rad ‐M1BNM ,τ RTP=232 ms) is observed. The reported discoveries in the field of Lewis pairs chemistry offer important insights into their structural dynamics, while also pointing to new opportunities for photoactive materials with implications for fast responsive detectors. -
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D0SC04715E
