title: Light-Induced Conversion of Chemical Permeability to Enhance Electron and Molecular Transfer in Nanoscale Assemblies.
abstract: In this paper, we demonstrate how photochemically enhancing the permeability of metal-organic assemblies results in a significant enhancement of the electrochemical activity of metal complexes located within the assembly. The molecular assemblies consist of different layers of redox-active metal complexes ([M(mbpy-py)3][PF6]2; M = Ru or Os) that are separated by redox-inactive spacers consisting of 1,4-bis[2-(4-pyridyl)ethenyl]benzene (BPEB) and PdCl2of variable thicknesses (0-13.4 nm). UV-irradiation (λ = 254 nm) of our assemblies induces a photochemical reaction in the redox-inactive spacer increasing the permeability of the assembly. The observed increase was evident by trapping organic (nBu4NBF4) and inorganic (NiCl2) salts inside the assemblies, and by evaluating the electrochemical response of quinones absorbed inside the molecular assemblies before and after UV irradiation. The increase in permeability is reflected by higher currents and a change in the directionality of electron transfer, i.e., from mono- to bidirectional, between the redox-active metal complexes and the electrode surface. The supramolecular structure of the assemblies dominates the overall electron transfer properties and overrules possible electron transfer mediated by the extensive π-conjugation of its individual organic components.
authors.affiliation: Department of Organic Chemistry, The Weizmann Institute of Science , 7610001 Rehovot, Israel.
authors.forename: Renata
authors.initials: R
authors.lastname: Balgley
authors.affiliation: Department of Organic Chemistry, The Weizmann Institute of Science , 7610001 Rehovot, Israel.
authors.forename: Graham
authors.initials: G
authors.lastname: de Ruiter
authors.affiliation: Department of Materials Science and Engineering, Northwestern University , Evanston, Illinois 60208, United States.
authors.forename: Guennadi
authors.initials: G
authors.lastname: Evmenenko
authors.affiliation: Department of Chemical Research Support, The Weizmann Institute of Science , Rehovot 7610001, Israel.
authors.forename: Tatyana
authors.initials: T
authors.lastname: Bendikov
authors.affiliation: Department of Organic Chemistry, The Weizmann Institute of Science , 7610001 Rehovot, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Lahav
authors.affiliation: Department of Organic Chemistry, The Weizmann Institute of Science , 7610001 Rehovot, Israel.
authors.forename: Milko E
authors.identifier: 0000-0003-4102-4220
authors.initials: ME
authors.lastname: van der Boom