Very Low Energy Vibrational Modes as a Fingerprint of H-Bond Network Formation: L-Cysteine on Au(111)
| Autor: | Maurizio Canepa, U. del Pennino, L. Lavagnino, V. De Renzi, Roberto Biagi, V. Corradini |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
Chemistry
Hydrogen bond Intermolecular force Analytical chemistry Surfaces Coatings and Films Electronic Optical and Magnetic Materials X RAY PHOTOELECTRON-SPECTROSCOPY Crystallography General Energy Adsorption TERAHERTZ SPECTROSCOPY X-ray photoelectron spectroscopy Cysteine/Au Interfaces Electron Spectroscopy HREESL SELF-ASSEMBLING MONOLAYERS Molecular vibration Monolayer Molecule REFLECTION-ABSORPTION Physical and Theoretical Chemistry Deposition (law) |
| Zdroj: | Journal of physical chemistry. C 112 (2008): 14439–14445. doi:10.1021/jp802206r info:cnr-pdr/source/autori:De Renzi, V; Lavagnino, L; Corradini, V; Biagi, R; Canepa, M; del Pennino, U/titolo:Very low energy vibrational modes as a fingerprint of H-bond network formation: L-cysteine on Au(111)/doi:10.1021%2Fjp802206r/rivista:Journal of physical chemistry. C/anno:2008/pagina_da:14439/pagina_a:14445/intervallo_pagine:14439–14445/volume:112 |
| DOI: | 10.1021/jp802206r |
| Popis: | The ultrahigh vacuum adsorption of cysteine layers on the Au(111) surface has been studied by means of X-ray photoelectron (XPS) and high-resolution energy loss spectroscopies (HREELS). Room-temperature deposition determined the formation of a quite heterogeneous first layer, where both weakly and strongly bound molecules coexist. Deposition at a slightly higher temperature (330 K) led instead to the formation of a homogeneous, self-assembled monolayer made of molecules chemisorbed through a thiolate bond. In the latter case, HREELS measurements have been interpreted in terms of a well-organized H-bond network made of zwitterionic molecules. Two vibrational modes, denoted as N and H modes, respectively, have been identified as distinguishing features of the homogeneous monolayer obtained at 330 K. The N mode lies at 3350 cm(-1) and is attributed to a stretching vibration of the N-H center dot center dot center dot O bond. The H mode, observed at 74 cm(-1) for full monolayer coverage, is assigned to a collective vibration of the two-dimensional H-bond network. At half-monolayer coverage, the H mode has been observed at 55 cm(-1). This red-shift indicates a coverage dependence of the H-mode frequency, which clearly supports its intermolecular origin. This finding is a nice example of the extreme sensitivity of low-frequency vibrational modes to the details of molecule-molecule interactions. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|