Adsorption properties of decyl thiocyanate and decanethiol on platinum substrates studied by sum-frequency generation spectroscopy

• Published in: Surface science Vol. 601; no. 5; pp. 1259 - 1264
• Main Authors: Sartenaer, Yannick, Dreesen, Laurent, Humbert, Christophe, Volcke, Cédric, Tourillon, Gérard, Louette, Pierre, Thiry, Paul A., Peremans, André
• Format: Journal Article Web Resource
• Language: English
• Published: Lausanne Elsevier B.V 01.03.2007; Amsterdam Elsevier Science; New York, NY Elsevier
• Subjects: Catalysis; Chemical Sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Decanethiol; Decyl thiocyanate; Environment and Society; Environmental Sciences; Exact sciences and technology; Physical, chemical, mathematical & earth Sciences; Physics; Physique; Physique, chimie, mathématiques & sciences de la terre; Platinum surfaces; Scanning tunnelling microscopy; Self-assembled monolayers; Sum-frequency generation spectroscopy; X-ray photoelectron spectroscopy; Decanethiol; Sum-frequency generation spectroscopy; Self-assembled monolayers; Scanning tunnelling microscopy; Decyl thiocyanate; Platinum surfaces; X-ray photoelectron spectroscopy; Sum frequency; Self-assembled layers; Scanning tunneling microscopy; Platinum; Transition elements; X-ray photoelectron spectra; "Self-assembled monolayers"; "Decyl thiocyanate"; "X-ray photoelectron spectroscopy"; "Sum-frequency generation spectroscopy"; "Decanethiol"; "Scanning tunnelling microscopy"; "Platinum surfaces"
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2006.12.066

Recently, thiocyanate groups were successfully used as precursors for thiolate assemblies. Indeed, they provide a useful alternative to thiol groups for self-assembly on metallic substrates. In order to check the adsorption properties and the quality of the thiocyanate-based self-assembled monolayers (SAMs), we use sum-frequency generation spectroscopy (SFG) and apply it to characterize the ad-layers of two similar molecules: decanethiol (DT) and decyl thiocyanate (DTCN) adsorbed on platinum surfaces. By comparing the SFG signals of the methyl and methylene vibration modes, we show that DTCN SAMs are less ordered than DT ones. These effects are related to the SAMs quality which depends on the molecular packing as highlighted by scanning tunnelling microscopy and X-ray photoelectron spectroscopy.