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Varying the Interpentacene Electronic Coupling to Tune Singlet Fission
- Source :
- Journal of the American Chemical Society. 141(15)
- Publication Year :
- 2019
-
Abstract
- We have designed and used four different spacers, denoted A-D, to connect two pentacenes and to probe the impact of intramolecular forces on the modulation of pentacene-pentacene interactions and, in turn, on the key steps in singlet fission (SF), that is, the 1(S1S0)-to-1(T1T1) as well as 1(T1T1)-to-5(T1T1) transitions by means of transient absorption and electron paramagnetic resonance measurements. In terms of the 1(S1S0)-to-1(T1T1) transition, a superexchange mechanism, that is, coupling to a higher-lying CT state to generate a virtual intermediate, enables rapid SF in A-D. Sizeable electronic coupling in A and B opens, on one hand, an additional pathway, that is, the population of a real intermediate, and changes, on the other hand, the mechanism to that of hopping. In turn, A and B feature much higher 1(T1T1) quantum yields than C and D, with a maximum value of 162% for A. In terms of the 1(T1T1)-to-5(T1T1) transition, the sizable electronic coupling in A and B is counterproductive, and C and D give rise to higher 5(T1T1)-to-(T1 + T1) quantum yields than A and B, with a maximum value of 85% for D.
- Subjects :
- Coupling
education.field_of_study
Chemistry
Population
General Chemistry
010402 general chemistry
01 natural sciences
Biochemistry
Molecular physics
Catalysis
0104 chemical sciences
law.invention
Colloid and Surface Chemistry
Superexchange
law
Intramolecular force
Singlet fission
Ultrafast laser spectroscopy
Electron paramagnetic resonance
education
Quantum
Subjects
Details
- ISSN :
- 15205126
- Volume :
- 141
- Issue :
- 15
- Database :
- OpenAIRE
- Journal :
- Journal of the American Chemical Society
- Accession number :
- edsair.doi.dedup.....fbf640a168aff7fadf18a88a024f492a