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Long Range Coherent Energy Transfer in Artificial Multichromophoric Antenna Systems-A Case of Breaking Kasha's Rule
Maryam Nazari Haghighi Pashaki1, Caroline D Bösch2, Florian Garo2
1Institute of Applied Physics, University of Bern, Sidlerstrasse 5, Bern, CH-3012, Switzerland.
Abstract:
Ultrafast long-range energy transfer with unitary quantum-yield has been studied in a novel family of artificial DNA-guided multichromophoric antenna complexes with phenanthrene moieties as light harvesters. By means of femtosecond transient absorption spectroscopy and time-dependent density function theory calculations, we demonstrate that the highly efficient long-range energy transfer occurs via a coherent mechanism. It is enabled by photoexcitation of higher lying delocalized excited states of phenanthrene, and hence, can be labelled anti-Kasha in nature. Moreover, we show the important contribution of exciplex formation between acceptor and closest donor.
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