title: Plasmonic scissors for molecular design.
abstract: Heterogeneous catalysts play an important role in surface catalytic reactions, but selective bond breaking and control of reaction products in catalytic processes remain significant challenges. High-vacuum tip-enhanced Raman spectroscopy (HV-TERS) is one of the best candidates to realize surface catalytic reactions. Herein, HV-TERS was employed in a new method to control dissociation by using hot electrons, generated from plasmon decay, as plasmonic scissors. In this method, the N=N bond in 4,4'-dimercaptoazobenzene was selectively dissociated by plasmonic scissors, and the reaction products formed from the radical fragment (SC6H5N) were controlled by varying the pH value. Under acidic conditions, p-aminothiophenol was produced from the radical fragment by attachment of hydrogen ions, whereas under alkaline conditions, 4-nitrobenzenethiol was obtained by attachment of oxygen ions to the substrate.
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P. O. Box 603-146, Beijing, 100190 (P. R. China). mtsun@iphy.ac.cn.
authors.forename: Mengtao
authors.initials: M
authors.lastname: Sun
authors.forename: Zhenglong
authors.initials: Z
authors.lastname: Zhang
authors.forename: Zee Hwan
authors.initials: ZH
authors.lastname: Kim
authors.forename: Hairong
authors.initials: H
authors.lastname: Zheng
authors.forename: Hongxing
authors.initials: H
authors.lastname: Xu
keywords: Raman spectroscopy; chemoselectivity; plasmon chemistry; radical reactions; surface chemistry