title: Photoproduction of proton gradients with pi-stacked fluorophore scaffolds in lipid bilayers.
abstract: Rigid p-octiphenyl rods were used to create helical tetrameric pi-stacks of blue, red-fluorescent naphthalene diimides that can span lipid bilayer membranes. In lipid vesicles containing quinone as electron acceptors and surrounded by ethylenediaminetetraacetic acid as hole acceptors, transmembrane proton gradients arose through quinone reduction upon excitation with visible light. Quantitative ultrafast and relatively long-lived charge separation was confirmed as the origin of photosynthetic activity by femtosecond fluorescence and transient absorption spectroscopy. Supramolecular self-organization was essential in that photoactivity was lost upon rod shortening (from p-octiphenyl to biphenyl) and chromophore expansion (from naphthalene diimide to perylene diimide). Ligand intercalation transformed the photoactive scaffolds into ion channels.
authors.affiliation: Department of Organic Chemistry, University of Geneva, Geneva, Switzerland.
authors.forename: Sheshanath
authors.initials: S
authors.lastname: Bhosale
authors.forename: Adam L
authors.initials: AL
authors.lastname: Sisson
authors.forename: Pinaki
authors.initials: P
authors.lastname: Talukdar
authors.forename: Alexandre
authors.initials: A
authors.lastname: Fürstenberg
authors.forename: Natalie
authors.initials: N
authors.lastname: Banerji
authors.forename: Eric
authors.initials: E
authors.lastname: Vauthey
authors.forename: Guillaume
authors.initials: G
authors.lastname: Bollot
authors.forename: Jiri
authors.initials: J
authors.lastname: Mareda
authors.forename: Cornelia
authors.initials: C
authors.lastname: Röger
authors.forename: Frank
authors.initials: F
authors.lastname: Würthner
authors.forename: Naomi
authors.initials: N
authors.lastname: Sakai
authors.forename: Stefan
authors.initials: S
authors.lastname: Matile
mesh_terms: D001555:Benzene Derivatives / Q000737:chemistry; D016227:Benzoquinones / Q000737:chemistry*; D004492:Edetic Acid; D004583:Electrons; D007094:Imides; D008024:Ligands; D008027:Light; D008051:Lipid Bilayers; D015394:Molecular Structure; D009281:Naphthalenes; D010084:Oxidation-Reduction; D010618:Phenanthrolines / Q000737:chemistry*; D010777:Photochemistry; D011522:Protons; D013696:Temperature; D013816:Thermodynamics
chemical_list: D001555:Benzene Derivatives; D016227:Benzoquinones; D007094:Imides; D008024:Ligands; D008051:Lipid Bilayers; D009281:Naphthalenes; D010618:Phenanthrolines; D011522:Protons; C542131:naphthalenediimide; C004532:quinone; D004492:Edetic Acid