title: Reversible trapping and reaction acceleration within dynamically self-assembling nanoflasks.
abstract: The chemical behaviour of molecules can be significantly modified by confinement to volumes comparable to the dimensions of the molecules. Although such confined spaces can be found in various nanostructured materials, such as zeolites, nanoporous organic frameworks and colloidal nanocrystal assemblies, the slow diffusion of molecules in and out of these materials has greatly hampered studying the effect of confinement on their physicochemical properties. Here, we show that this diffusion limitation can be overcome by reversibly creating and destroying confined environments by means of ultraviolet and visible light irradiation. We use colloidal nanocrystals functionalized with light-responsive ligands that readily self-assemble and trap various molecules from the surrounding bulk solution. Once trapped, these molecules can undergo chemical reactions with increased rates and with stereoselectivities significantly different from those in bulk solution. Illumination with visible light disassembles these nanoflasks, releasing the product in solution and thereby establishes a catalytic cycle. These dynamic nanoflasks can be useful for studying chemical reactivities in confined environments and for synthesizing molecules that are otherwise hard to achieve in bulk solution.
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Hui
authors.initials: H
authors.lastname: Zhao
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Soumyo
authors.initials: S
authors.lastname: Sen
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: T
authors.initials: T
authors.lastname: Udayabhaskararao
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Michał
authors.initials: M
authors.lastname: Sawczyk
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Kristina
authors.initials: K
authors.lastname: Kučanda
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Debasish
authors.initials: D
authors.lastname: Manna
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Pintu K
authors.initials: PK
authors.lastname: Kundu
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Ji-Woong
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607, USA.|Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60607, USA.|Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, Illinois 60607, USA.
authors.forename: Petr
authors.initials: P
authors.lastname: Král
authors.affiliation: Department of Organic Chemistry, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Rafal
authors.initials: R
authors.lastname: Klajn