Self-assembled monolayers of aromatic omega-aminothiols on gold: surface chemistry and reactivity

Langmuir. 2010 Mar 16;26(6):3949-54. doi: 10.1021/la903293b.

Abstract

Amino-terminated self-assembled monolayers on gold substrates were studied by X-ray photoelectron spectroscopy (XPS), near-edge X-ray absorption fine structure (NEXAFS) measurements, and atomic force microscopy (AFM). Two different omega-amino-4,4'-terphenyl substituted alkanethiols of the general structure H(2)N-(C(6)H(4))(3)-(CH(2))(n)-SH (ATPn) were used: 2-(4''-amino-1,1':4',1''-terphenyl-4-yl)ethane-1-thiol (n = 2, ATP2) and 3-(4''-amino-1,1':4',1''-terphenyl-4-yl)propane-1-thiol (n = 3, ATP3). Moreover, the addressability of amino groups within the films was investigated by chemical derivatization of ATPn SAMs with 3,5-bis(trifluoromethyl)phenyl isothiocyanate (ITC) forming fluorinated thiourea ATPn-F films. Evaluation of high-resolution C 1s and N 1s XPS data revealed successful derivatization of at least 50% of surface amino species. Furthermore, it could be demonstrated by angle-resolved NEXAFS spectroscopy that chemical derivatization with ITC has no noticeable influence on the preferential upright orientation of the molecules in the SAMs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gold / chemistry*
  • Microscopy, Atomic Force
  • Spectrum Analysis / methods
  • Sulfhydryl Compounds / chemistry*
  • Surface Properties

Substances

  • Sulfhydryl Compounds
  • Gold