title: A switchable self-assembling and disassembling chiral system based on a porphyrin-substituted phenylalanine-phenylalanine motif.
abstract: Artificial light-harvesting systems have until now not been able to self-assemble into structures with a large photon capture cross-section that upon a stimulus reversibly can switch into an inactive state. Here we describe a simple and robust FLFL-dipeptide construct to which a meso-tetraphenylporphyrin has been appended and which self-assembles to fibrils, platelets or nanospheres depending on the solvent composition. The fibrils, functioning as quenched antennas, give intense excitonic couplets in the electronic circular dichroism spectra which are mirror imaged if the unnatural FDFD-analogue is used. By slightly increasing the solvent polarity, these light-harvesting fibres disassemble to spherical structures with silent electronic circular dichroism spectra but which fluoresce. Upon further dilution with the nonpolar solvent, the intense Cotton effects are recovered, thus proving a reversible switching. A single crystal X-ray structure shows a head-to-head arrangement of porphyrins that explains both their excitonic coupling and quenched fluorescence.
authors: Department of Chemistry, Bioinorganic Chemistry Laboratory, University of Crete, Vassilika Vouton, Heraklion, 70013 Crete, Greece.
authors: Georgios
authors: 0000-0003-1237-9962
authors: G
authors: Charalambidis
authors: Department of Materials Science and Technology, University of Crete, Vassilika Vouton, Heraklion, 70013 Crete, Greece.|Institute of Electronic Structure and Laser (I.E.S.L.) Foundation for Research and Technology Hellas (FO.R.T.H.) Vassilika Vouton, Heraklion, 70013 Crete, Greece.
authors: Evangelos
authors: E
authors: Georgilis
authors: Department of Chemistry, Bioinorganic Chemistry Laboratory, University of Crete, Vassilika Vouton, Heraklion, 70013 Crete, Greece.
authors: Manas K
authors: 0000-0002-6297-2070
authors: MK
authors: Panda
authors: Karlsruhe Institute of Technology (KIT), Institute of Inorganic Chemistry, Engesserstrasse 15, D-76131 Karlsruhe, Germany.
authors: Christopher E
authors: CE
authors: Anson
authors: Karlsruhe Institute of Technology (KIT), Institute of Inorganic Chemistry, Engesserstrasse 15, D-76131 Karlsruhe, Germany.|Karlsruhe Institute of Technology (KIT), Institute for Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
authors: Annie K
authors: 0000-0003-3944-7427
authors: AK
authors: Powell
authors: Karlsruhe Institute of Technology, Institute for Synchrotron Radiation and ANKA, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
authors: Stephen
authors: S
authors: Doyle
authors: Karlsruhe Institute of Technology, Institute for Synchrotron Radiation and ANKA, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
authors: David
authors: D
authors: Moss
authors: Karlsruhe Institute of Technology, Institute for Synchrotron Radiation and ANKA, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany.
authors: Tobias
authors: T
authors: Jochum
authors: School of Chemistry, EPSRC National Crystallography Service, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
authors: Peter N
authors: PN
authors: Horton
authors: School of Chemistry, EPSRC National Crystallography Service, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
authors: Simon J
authors: SJ
authors: Coles
authors: Department of Physics, Chemistry and Biology, Linköping University, SE-581 83 Linköping, Sweden.|Swedish e-Science Research Centre (SeRC), Linköping University, SE-581 83 Linköping, Sweden.
authors: Mathieu
authors: M
authors: Linares
authors: Département de Chimie, Chimie des Matériaux Nouveaux and Centre d'Innovation et de Recherche en Matériaux Polymères, Université de Mons-UMONS/Materia Nova, Place du Parc, 20, B-7000 Mons, Belgium.
authors: David
authors: D
authors: Beljonne
authors: Aix Marseille Université, CNRS FR 1739, Spectropole, Avenue Escadrille Normandie Niemen, F-13397 Marseille, France.
authors: Jean-Valère
authors: JV
authors: Naubron
authors: Karlsruhe Institute of Technology (KIT), Institute of Applied Physics and Center for Functional Nanostructures (CFN), D-76131 Karlsruhe, Germany.
authors: Jonas
authors: J
authors: Conradt
authors: Karlsruhe Institute of Technology (KIT), Institute of Applied Physics and Center for Functional Nanostructures (CFN), D-76131 Karlsruhe, Germany.
authors: Heinz
authors: 0000-0002-3698-1512
authors: H
authors: Kalt
authors: Department of Materials Science and Technology, University of Crete, Vassilika Vouton, Heraklion, 70013 Crete, Greece.|Institute of Electronic Structure and Laser (I.E.S.L.) Foundation for Research and Technology Hellas (FO.R.T.H.) Vassilika Vouton, Heraklion, 70013 Crete, Greece.
authors: Anna
authors: A
authors: Mitraki
authors: Department of Chemistry, Bioinorganic Chemistry Laboratory, University of Crete, Vassilika Vouton, Heraklion, 70013 Crete, Greece.
authors: Athanassios G
authors: AG
authors: Coutsolelos
authors: Aix Marseille Univ, CNRS, Centrale Marseille, Institut des Sciences Moléculaires de Marseille (iSm2), UMR 7313, Chirosciences, Avenue Escadrille Normandie Niemen, Service 442, F-13397 Marseille, France.
authors: Teodor Silviu
authors: 0000-0003-4614-2461
authors: TS
authors: Balaban