Electrochemical surface derivation of glassy carbon by the reduction of triaryl- and alkyldiphenylsulfonium salts

K.H. Vase, A.H. Holm, Kion Norrman, S.U. Pedersen, K. Daasbjerg

    Research output: Contribution to journalJournal articleResearchpeer-review

    Abstract

    The range of materials susceptible to electrochemically assisted grafting onto carbon materials has been expanded to include a new group of compounds. This new approach is based on the reduction of symmetrical or unsymmetrical triarylsulfonium salts and alkyldiphenylsulfonium salts. Our findings suggest that it is possible to form layers of aryl moieties on the surface and that the unsymmetrical triarylsulfonium salts cleave upon reduction in a direction dictated by the substituent on the rings.(i.e., (4-methoxyphenyl)diphenylsulfonium salt leads to a film made predominantly of phenyl groups, whereas (4-chlorophenyl)diphenylsulfonium salt leads to a mixture of phenyl and chlorophenyl groups). These relationships may be understood by considering the inductive nature of the substituent with regard to the aryl-S bonds and are supported by preparative experiments. Upon reduction, the alkyldiphenylsulfonium salts are found to cleave almost exclusively to an alkyl radical and diphenyl sulfide. As judged from the electrochemical blocking properties of the films made from such species, either relatively thick or compact films are formed. The mass spectrometric analysis indicates that the films are made of a combination of alkyl and aryl groups and possibly related structural derivatives. Importantly, our findings provide evidence that it is possible to graft electrode surfaces with reactive aryl radicals even using precursors reduced at potentials that are substantially more negative than the estimated reduction potential of the grafting radical.
    Original languageEnglish
    JournalLangmuir
    Volume24
    Issue number1
    Pages (from-to)182-188
    ISSN0743-7463
    DOIs
    Publication statusPublished - 2008

    Fingerprint Dive into the research topics of 'Electrochemical surface derivation of glassy carbon by the reduction of triaryl- and alkyldiphenylsulfonium salts'. Together they form a unique fingerprint.

    Cite this