Erlangen 2018 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 21: Advanced Time-Resolved Spectroscopy
MO 21.2: Vortrag
Donnerstag, 8. März 2018, 14:15–14:30, PA 2.150
Diffusion Controlled Singlet Fission of a Tetracene Derivative in Solution — •Nikolaus Wollscheid1, Nicolò Alagna1, José Luis Perez Lustres1, Tiago Buckup1, Sebastian Hahn2, Uwe Bunz2, and Marcus Motzkus1 — 1Physikalisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg — 2Organisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg
Singlet fission (SF) is the process by which one excited singlet state yields two triplet states upon close interaction of two chromophores. This ultrafast photoreaction was first observed in solid state and has strong implications in organic photovoltaics [1]. SF was also reported in concentrated solutions, where the diffusion of the reaction partners extends the dynamics to longer timescales [2]. This eases the identification of the involved species and helps to disentangle the mechanism. In this work, we use ultrafast transient absorption (TA) spectroscopy to investigate concentrated solutions of an aza-substituted tetracene derivative in toluene. Measurements at different concentrations show: a) the correlation between singlet decay and triplet formation and b) acceleration of the reaction dynamics with increasing concentration. Both observations together indicate a diffusion mediated SF process. Spectral analysis suggests a kinetic model involving an intermediate TT state.
M. Smith and J. Michl, Chem. Rev., 110, 6891, (2010)
B. Walker, A. J. Musser, D. Beljonne, R. Friend, Nat. Chem., 5, 1019 (2013)