TY - JOUR
T1 - Polymorph acceptor-based triads with photoinduced TADF for UV sensing
AU - Gužauskas, Matas
AU - Narbutaitis, Edgaras
AU - Volyniuk, Dmytro
AU - Baryshnikov, Glib V.
AU - Minaev, Boris F.
AU - Ågren, Hans
AU - Chao, Yu Chiang
AU - Chang, Chia Chih
AU - Rutkis, Martins
AU - Grazulevicius, Juozas V.
N1 - Publisher Copyright:
© 2021 Elsevier B.V.
PY - 2021/12/1
Y1 - 2021/12/1
N2 - In contrast to many donor–acceptor type organic luminophores exhibiting thermally activated delayed fluorescence (TADF), two deep blue TADF emitters designed in this work contain only typical electron accepting moieties with different electron accepting abilities. Derivatives of benzophenone and diphenylsulfone substituted with phenothiazine-5,5-dioxide donor moieties were synthesized and studied. In addition to the TADF, green to blue emission color switching and strong fluorescence intensity enhancement by more than 60 times was detected for THF solution of the derivative of phenothiazine-5,5-dioxide and benzophenone under increase of UV excitation dose. We proved by a variety of experimental and theoretical studies that the unusual photophysical properties of the derivative of benzophenone are mainly related to the formation of different conformers. The photostimulated intensity enhancement of the compound is due to the rise of the quantity of triplet states and their further crossing to singlet states. To our knowledge, this is the first observation of a combination of photoinduced color switching and triplet-dependent emission intensity enhancement. These properties are shown to be useful for UV sensing with very low detection limits (less than 10 μW/cm2 for the toluene solution). Under gradual increase of UV excitation dose, the DMF solution demonstrated a green → blue color swishing from (0.34; 0.44) to (0.17; 0.18) of CIE coordinates that can be detected by naked eye.
AB - In contrast to many donor–acceptor type organic luminophores exhibiting thermally activated delayed fluorescence (TADF), two deep blue TADF emitters designed in this work contain only typical electron accepting moieties with different electron accepting abilities. Derivatives of benzophenone and diphenylsulfone substituted with phenothiazine-5,5-dioxide donor moieties were synthesized and studied. In addition to the TADF, green to blue emission color switching and strong fluorescence intensity enhancement by more than 60 times was detected for THF solution of the derivative of phenothiazine-5,5-dioxide and benzophenone under increase of UV excitation dose. We proved by a variety of experimental and theoretical studies that the unusual photophysical properties of the derivative of benzophenone are mainly related to the formation of different conformers. The photostimulated intensity enhancement of the compound is due to the rise of the quantity of triplet states and their further crossing to singlet states. To our knowledge, this is the first observation of a combination of photoinduced color switching and triplet-dependent emission intensity enhancement. These properties are shown to be useful for UV sensing with very low detection limits (less than 10 μW/cm2 for the toluene solution). Under gradual increase of UV excitation dose, the DMF solution demonstrated a green → blue color swishing from (0.34; 0.44) to (0.17; 0.18) of CIE coordinates that can be detected by naked eye.
KW - Benzophenone
KW - Diphenylsulfone
KW - Phenothiazine-5,5-dioxide
KW - UV sensor
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U2 - 10.1016/j.cej.2021.131549
DO - 10.1016/j.cej.2021.131549
M3 - Article
AN - SCOPUS:85112276277
SN - 1385-8947
VL - 425
JO - Chemical Engineering Journal
JF - Chemical Engineering Journal
M1 - 131549
ER -