Monolayers of trimesic and isophthalic acid on Cu and Ag: the influence of coordination strength on adsorption geometry

Self-Assembled Monolayers of Oligophenylenecarboxylic Acids on Silver Formed at the Liquid–Solid Interface

“…With the need of using a combination of microscopy and spectroscopy highlighted by the study of TMA 37 and BPTCA 38 , here we report the results of scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS) and near-edge X-ray adsorption fine structure (NEXAFS) spectroscopy in combination with DFT calculations to assist the interpretation of the data. For the studies Au/mica substrates were used, which have been modified by an underpotential deposited (UPD) bilayer of Ag.…”

“…The C 1s spectra have been decomposed into components characteristic of emissions from COOH (~288.5 eV), COO -(~287 eV) and the aromatic ring carbons (284-284.5 eV). 24,[35][36][37][65][66] Following previous work on SAMs of molecules featuring an isophthalic acid moiety, all spectra were fitted with one component for each signal with the exception of the main emission, which has an additional small component located at2 85.2 eV with an area of 2-6 % of the main peak. [35][36][37][38] The origin of this small feature is not fully clear.…”

“…The weaker coordination bond between the carboxylate and Ag compared to Cu results in a very different balance between molecule-substrate and intermolecular interactions. [37][38] This, in particular, is pinpointed by pronouncedly different adsorption geometries of TMA and BPTCA on Ag where a monopodal configuration is realised compared to Cu which yields a bipodal configuration.…”

“…[32][33][34] To this small set of spectroscopic studies, benzene-1,3-dicarboxylic acid (isophthalic acid, IPA), benzene-1,3,5-tricarboxylic acid (trimesic acid, TMA) and biphenyl-3,4′,5-tricarboxylic acid (BPTCA) have recently been added. [35][36][37][38] Employing a combination of X-ray spectroscopies and scanning tunneling microscopy at molecular resolution, these studies revealed that ordered layers are formed on Cu and Ag prepared as underpotential deposited layers on Au. Apart from providing insights into the very initial stages of thin film * There are varying interpretations of the term self-assembled monolayer.…”

Adsorption and charge transfer interactions of bi-isonicotinic acid on Ag(111)

“…Firstly, for the case of partial deprotonation of the monolayer molecules, we would expect a third, lower binding energy peak in the O 1s and a further peak in the C 1s region close to the carboxylic group binding energy. Cebula et al 14 have recently studied similar small organic molecules featuring carboxylic acid groups and have seen this behaviour when using electrochemical underpotential deposition. While their XPS findings may not translate directly to the present study (where the deposition technique does not create ionised species by design), the comparison is still of value.…”