title: Self-assembled monolayers of aromatic omega-aminothiols on gold: surface chemistry and reactivity.
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.
authors.affiliation: BAM Bundesanstalt für Materialforschung und -prüfung, D-12203 Berlin, Germany.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Dietrich
authors.forename: Nora
authors.initials: N
authors.lastname: Graf
authors.forename: Thomas
authors.initials: T
authors.lastname: Gross
authors.forename: Andreas
authors.initials: A
authors.lastname: Lippitz
authors.forename: Björn
authors.initials: B
authors.lastname: Schüpbach
authors.forename: Asif
authors.initials: A
authors.lastname: Bashir
authors.forename: Christof
authors.initials: C
authors.lastname: Wöll
authors.forename: Andreas
authors.initials: A
authors.lastname: Terfort
authors.forename: Wolfgang E S
authors.initials: WE
authors.lastname: Unger
mesh_terms: D006046:Gold / Q000737:chemistry*; D018625:Microscopy, Atomic Force; D013057:Spectrum Analysis / Q000379:methods; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D013438:Sulfhydryl Compounds; D006046:Gold