Self-assembly of a pyridine-terminated thiol monolayer on Au(111).
Self-assembled monolayers (SAMs) of 3-(4-pyridine-4-yl-phenyl)-propane-1-thiol (PyP3) on Au(111)/mica have been studied by scanning tunneling microscopy (STM), polarization-modulated infrared reflection absorption spectroscopy (PM-IRRAS), high-resolution X-ray photoemission spectroscopy (HRXPS), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The quality of the SAM is found to be strongly dependent on the solvent. Substantial gold corrosion is observed if pure ethanol is used. In contrast, highly ordered and densely packed SAMs are formed from acetonitrile or a KOH/ethanol mixture. The structure is described by a 2 radical3 x radical3 unit cell with the aromatic moiety oriented nearly perpendicular to the surface. The PyP3 films form with the pyridine moiety deprotonated. Variation of pH allows reversible protonation without measurable damage of the SAM.
Silien
Christophe
C
EaStChem School of Chemistry, University of St. Andrews, North Haugh, St. Andrews KY16 9ST, UK. cjcs@st-andrews.ac.uk
Buck
Manfred
M
Goretzki
Gudrun
G
Lahaye
Dorothée
D
Champness
Neil R
NR
Weidner
Tobias
T
Zharnikov
Michael
M
D000538:Aluminum Silicates / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D008567:Membranes, Artificial; D016252:Microscopy, Scanning Tunneling; D015394:Molecular Structure; D010316:Particle Size; D011725:Pyridines / Q000138:chemical synthesis / Q000737:chemistry*; D013057:Spectrum Analysis; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013499:Surface Properties; D014965:X-Rays
C535262:3-(4-pyridine-4-yl-phenyl)-propane-1-thiol; D000538:Aluminum Silicates; D008567:Membranes, Artificial; D011725:Pyridines; D013438:Sulfhydryl Compounds; D006046:Gold; C011934:mica