Kinetics of Formation of Long-Chain n-Alkanethiolate Monolayers on Polycrystalline Gold

• DOI: 10.1021/la970052a
• Publication Date: 2002-07-26T05:15:42Z
• Authors: Farid Bensebaa; Raluca Voicu; Laurent Huron; Thomas H. Ellis; Erik Kruus
• Keywords: Immersion

The effect of immersion time on the ordering properties self-assembled docosanethiolate (C22) monolayers has been studied by reflection/absorption infrared spectroscopy (RAIRS). Starting with a chemically cleaned polycrystalline gold surface, we have found that an 45 s in micromolar thiol solutions is sufficient to produce ordered "monolayer" films. These films RAIR spectral features (peak position, line width, and integrated intensity) similar those obtained much longer times. Decreasing below gradually increases disorder. temperature dependence CH2 antisymmetric stretching (d-) peak position 120 identical ones very long (0.5 h several days). In contrast, 5 disorder at lower temperature. Apart from temperature, large solvent observed based real-time RAIRS measurements continuing film during aging vacuum. Finally, new assignment shoulder appearing around 2931 cm-1 proposed. We present arguments suggesting generally accepted Fermi resonance this should be modified include contribution another vibrational mode.