Two-dimensional self-assembly of benzotriazole on an inert substrateElectronic supplementary information (ESI) available: NEXAFS N K-edge comparison with calculated N LDOS, C 1s and N 1s X-ray photoemission spectra, additional STM images, gas-phase and adsorbed dimer calculations, vibrational spectra calculation and comparison with HREELS. See DOI: 10.1039/c6nr00821f

• Main Authors: Grillo, F, Garrido Torres, J. A, Treanor, M.-J, Larrea, C. R, Götze, J. P, Lacovig, P, Früchtl, H. A, Schaub, R, Richardson, N. V
• Format: Journal Article
• Published: 28.04.2016
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c6nr00821f

The ultra-high vacuum (UHV) room temperature adsorption of benzotriazole (BTAH), a well-known corrosion inhibitor for copper, has been investigated on the pristine Au(111) surface using a combination of surface sensitive techniques. The dimensionality of the molecule is reduced from the 3D crystal structure to a 2-dimensional surface confinement, which induces the formation of hydrogen bonded 1-dimensional molecular chains consisting of alternating pro-S and pro-R enantiomers mainly. The 0-dimensional system is characteristic of gas-phase BTAH, which undergoes a tautomeric equilibrium, with consequences for the resulting adsorbed species. The balance between hydrogen bonding, inter-chain van der Waals interactions and surface-molecule interactions, and the correlation with the dimensionality of the system, are discussed in light of the experimental results and a computational description of the observed features. Fine tuning of experimental conditions allows dimensional control of benzotriazole species adsorbed on Au(111), revealing a subtle interplay between H-bonding, vdW inter-adsorbate and surface-adsorbate interactions, as highlighted both experimentally and theoretically.