发布时间：2016-11-04 14:17:45 点击：1132
题 目：Light-controlled supramolecular interactions between ligand-functionalized nanoparticles
The Weizmann Institute of Science, Department of Organic Chemistry，Israel
地 点：化学楼 H201（蒋雯若报告厅）
联系人：强琚莉 (firstname.lastname@example.org)，王乐勇 (email@example.com)
Education：08/2004 - 10/2009 :Northwestern University, Ph.D. in Chemical and Biological Engineering
09/2001 - 07/2004 :University of Warsaw, Undergraduate studies and M.Sc. in Chemistry, Summa cum Laude
This talk will present two approaches we have recently developed to control supramolecular interactions between ligand-functionalized nanoparticles using light.
In the first approach, metallic nanoparticles are functionalized with monolayers of the photoswitchable azobenzene and spiropyran ligands. We have demonstrated that as these nanoparticles self-assemble, they can readily 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 “dynamic nanoflasks”, releasing the product in solution and thereby establishes a catalytic cycle.
The second approach eliminates the need to functionalize the surfaces of nanoparticles with light-sensitive ligands, and is based on the use of a photoswitchable medium that responds to light in such a way that it modulates the interparticle interactions. We have shown that assembly proceeds quantitatively and without apparent fatigue, both in methanolic solutions and in gels. Exposing the gels to light in a spatially controlled manner allowed us to draw images that spontaneously disappeared after a specific period of time.
Finally, a newly developed system will be discussed, which operates in pure water as the solvent.
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