TY - JOUR
T1 - Synergetic Role of Conformational Flexibility and Electronic Coupling for Quantitative Intramolecular Singlet Fission
AU - Nakamura, Shunta
AU - Sakai, Hayato
AU - Nagashima, Hiroki
AU - Fuki, Masaaki
AU - Onishi, Kakeru
AU - Khan, Ramsha
AU - Kobori, Yasuhiro
AU - Tkachenko, Nikolai V.
AU - Hasobe, Taku
N1 - Funding Information:
This work was partially supported by JSPS KAKENHI grant numbers of JP19H00888 and JP20K21174 and Grant-in-Aid for Transformative Research Areas, “Dynamic Exciton” (JP20H05832) to Y.K. and by JSPS KAKENHI grant nos. JP18H01957, JP18K19063, JP20H05234, JP20KK0120, JP21H01908, and JP21K19011 to T.H., JP20K05652 to H.S., and JP20J13133 to S.N. JP19K15506 to H.N. R.K. acknowledges Doctoral program of Tampere University for financial support. We are grateful to Dr. Tatsuo Nakagawa and Hiroaki Hanada (Unisoku Co., Ltd.) for picosecond transient absorption measurements by the Randomly Interleaved Pulse Train Method. This work was partially carried out by the joint research program of Molecular Photoscience Research Center, Kobe University, and the Research Program of “Five-star Alliance” in “NJRC Mater. & Dev.”
Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/8/26
Y1 - 2021/8/26
N2 - We present a novel design concept of molecular dimers for quantitative individual triplet yield (φT) through intramolecular singlet fission. We synthesized a series of tetracene (Tc) dimers bridged by different phenylene-based linkers, focusing on the conformational flexibility in addition to the electronic coupling. In transient absorption measurements, a 4,4′-biphenyl-bridged Tc dimer with weaker electronic coupling and larger conformational flexibility exhibited the quantitative φT: 196 ± 12% at high excitation energy. Moreover, decoupled spins associated with conformational change were directly characterized by time-resolved electron paramagnetic resonance. Strong interplay of the geometry change and electronic localization was revealed on the triplet pair dissociation through magnitudes of spin-spin exchange couplings. Thus, a synergetic role of conformational flexibility and electronic coupling in quantitative φT was clarified.
AB - We present a novel design concept of molecular dimers for quantitative individual triplet yield (φT) through intramolecular singlet fission. We synthesized a series of tetracene (Tc) dimers bridged by different phenylene-based linkers, focusing on the conformational flexibility in addition to the electronic coupling. In transient absorption measurements, a 4,4′-biphenyl-bridged Tc dimer with weaker electronic coupling and larger conformational flexibility exhibited the quantitative φT: 196 ± 12% at high excitation energy. Moreover, decoupled spins associated with conformational change were directly characterized by time-resolved electron paramagnetic resonance. Strong interplay of the geometry change and electronic localization was revealed on the triplet pair dissociation through magnitudes of spin-spin exchange couplings. Thus, a synergetic role of conformational flexibility and electronic coupling in quantitative φT was clarified.
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U2 - 10.1021/acs.jpcc.1c04734
DO - 10.1021/acs.jpcc.1c04734
M3 - Article
AN - SCOPUS:85114009615
SN - 1932-7447
VL - 125
SP - 18287
EP - 18296
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 33
ER -