Spectroscopic Study of Thiophene–Pyrrole-Containing S,N-Heteroheptacenes Compared to Acenes and Phenacenes

Title data

Rudnick, Alexander ; Wetzel, Christoph ; Tscheuschner, Steffen ; Schmalz, Holger ; Vogt, Astrid ; Greiner, Andreas ; Bässler, Heinz ; Mena-Osteritz, Elena ; Bäuerle, Peter ; Köhler, Anna:
Spectroscopic Study of Thiophene–Pyrrole-Containing S,N-Heteroheptacenes Compared to Acenes and Phenacenes.
In: The Journal of Physical Chemistry B. Vol. 121 (2017) Issue 31 . - pp. 7492-7501.
ISSN 1520-5207
DOI: https://doi.org/10.1021/acs.jpcb.7b02935

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Abstract in another language

In this study, we report a detailed spectroscopic study concerning the energy levels and vibrational structure of thiophene–pyrrole-containing S,N-heteroacenes. The aim of the study is first, to understand the differences in the photoluminescence (PL) efficiencies in this structurally similar series and second, to compare the electronic structure of S,N-heteroacenes to that of linear acenes and phenacenes, with a view to derive guidelines for the design of singlet fission materials. For S,N-heteroacenes comprising seven fused heterocyclic rings, we observe a higher PL quantum yield for derivatives with terminal thienothiophene units than for thienopyrrole-capped ones. This is assigned to a stronger tendency of the thienopyrrole-capped derivatives to form nonemissive associates in dilute solution, producing emissive excimers at higher concentration. By conducting time-resolved PL studies at 77 K, we further determine the lowest singlet and triplet energies for the S,N-heteroacenes with three, five, and seven fused rings. We show that their energies evolve with oligomer length analogously to those of phenacenes, yet in a fundamentally different way from that of linear acenes. This difference in evolution is attributed to the increasingly biradical character in acenes with increasing chain length in contrast to the S,N-heteroacenes and phenacenes.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Additional notes:	Preprint
Institutions of the University:	Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics II - Optoelectronics of Soft Matter > Chair Experimental Physics II - Optoelectronics of Soft Matter - Univ.-Prof. Dr. Anna Köhler Faculties Faculties > Faculty of Mathematics, Physics und Computer Science Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics Faculties > Faculty of Mathematics, Physics und Computer Science > Department of Physics > Chair Experimental Physics II - Optoelectronics of Soft Matter
Result of work at the UBT:	Yes
DDC Subjects:	500 Science > 530 Physics
Date Deposited:	04 Aug 2017 05:56
Last Modified:	08 Feb 2022 13:24
URI:	https://eref.uni-bayreuth.de/id/eprint/39047