Ferrocenylalkylthiolates as a probe of heterogeneity in binary self-assembled monolayers on gold

Yoon Suk Lee, Todd C. Sutherland, Simona Rucareanu, R. Brace Lennox

Research output: Journal article publicationJournal articleAcademic researchpeer-review

132 Citations (Scopus)

Abstract

The oft-cited complexity of tethered ferrocene electrochemistry in single component (FcRS-) or binary (FcRS-/ CH3R′S-) self-assembled monolayers (SAMs) on gold has been investigated. The complex voltammetry is shown to be linked to local electrostatics caused by the formation of the ferrocenium ion. This conclusion is reached by studying model effects in binary SAMs, where a cationic alkylthiolate (H3N+C11S-Au) is mixed with FcC12S-Au. A fitting procedure involving both a Gaussian and a Lorentzian distribution is used for deconvolution of the two peaks which are consistently observed in the SAMs when χFcsurf≥0.2. The lower-potential (Eo′ = 250 mV) and higherpotential (Eo′ = 350 mV) voltammetric peaks are assigned to Fc moieties in "isolated" and "clustered" states, respectively. Use of this method to better understand SAM structure is demonstrated by distinguishing the degree of homogeneity in two binary SAMs of similar composition.
Original languageEnglish
Pages (from-to)4438-4444
Number of pages7
JournalLangmuir
Volume22
Issue number9
DOIs
Publication statusPublished - 25 Apr 2006
Externally publishedYes

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Surfaces and Interfaces
  • Spectroscopy
  • Electrochemistry

Cite this