Supramolecular Photosystems with Precise Spatial Organization of Dyes

Prof. Frank Würthner

Institut für Organische Chemie & Center for Nanosystems Chemistry
Universität Würzburg, Germany               

Natural photosynthesis provides a blueprint for a future technology that may deliver clean energy for a sustainable hydrogen and/or carbon based cycle. In natural photosynthesis various molecular components are properly assembled to accomplish light harvesting, charge separation and catalytic water splitting into hydrogen (NADH) and oxygen. Understanding the operating principles of the natural photosynthetic apparatus and designing artificial counterparts that accomplish the elemental steps of natural photosynthesis are therefore topics of considerable scientific interest [1].
In this lecture I will highlight some recent achievements of my laboratory with regard to photophysical processes occurring in dye aggregates with exactly tailored size and supramolecular arrangement [2,3]. In the first part of my lecture I will show that the interaction of two dyes in cyclophanes opens up entirely new relaxation pathways such as excimer formation, symmetry-breaking charge separation (SB-CS), and triplet state population. The second part of my talk will deal with larger macrocyclic and self-assembled nanostructures. Here I will give insights into exciton transport and light-harvesting, and furthermore discuss recent achievements in “living” supramolecular polymerization to give highly fluorescent J-aggregates with exciton diffusion lengths up to 100 nm [4].

[1] P. Frischmann, K. Mahata, F. Würthner, Chem. Soc. Rev.2013, 42, 1847–1870.
[2] F. Würthner, C. R. Saha-Möller, B. Fimmel, S. Ogi, P. Leowanawat, D. Schmidt, Chem. Rev. 2016, 116, 962–1052.
[3] P. Spenst, F. Würthner, J. Photochem. Photobiol. C 2017, 31, 114–138.
[4] W. Wagner, M. Wehner, V. Stepanenko, S. Ogi, F. Würthner, Angew. Chem. Int. Ed. 2017, 56, 16008–16012