Adsorption and Ordering of Resorcinare Layers on Planar and Colloidal Gold and the Influence of Surface Modification: A SERS and IRRAS Study

Abstract

Near-infrared surface-enhanced Raman spectroscopy and infrared re¯ection-absorption spectroscopy have been applied to investigate adsorption and ordering processes of resorcin arene cavitands at interfaces. Colloidal gold was applied in the case of NIR-Ram an m easurem ents, and planar gold substrates were used for re¯ection spectroscopy. Selected cavitands substituted on their upper rim with different functionalities were em ployed as probe m olecules. An assignment of vibrational bands is presen ted. Interactions between probe m olecules and substrates are present in all cases. From Raman measurements, it is dif® cult to deduce an orientation of the probe molecule adsorbed onto the gold particle, as the selection rules for SERS cannot be applied straightforwardly. Furtherm ore, an orientation depends on a proper assignment of vibrational bands. Infrared spectroscopy shows that the orientation of the resorcinarene m olecules deposited on a planar gold or gold/m onolayer interface is in¯uenced by the underlying substrate. The directing effect, however, does not extend into the adjoining bulk of the sample layer.

Dispersion and Stability Studies of Resorcinarene-Encapsulated Gold Nanoparticles

“…29 The remaining peaks in the spectra could not be reliably assigned due to the scarcity of empirical data for the vibrational modes of pentasubstituted aromatic systems. 30 We note that the Raman and SERS spectra in this study bear few similarities to those of closely related resorcinarenes, 31 indicative of the present limitations of Raman spectral assignments based on structural correlations. In the case of tetraarylthiol 2, a strong SERS signal with a maximum at 255 cm -1 and a shoulder between 275 and 300 cm -1 is observed.…”

In situ characterisation of the aqueous gold colloid interface using CO as a surface probe: IR spectroscopic studies

“…In the chemical literature, in situ IR evidence for surface interactions of CO with dispersed Au colloids per se is lacking. This is despite the prevalence of surface enhanced Raman scattering (SERS)-based studies of adsorbates to gold and silver colloids [12,13]. The Au colloid surface is more difficult to study by IR because CO adsorption on gold surfaces is much weaker than adsorption on Pt and Pd owing to Au having a filled d 10 electron configuration.…”

Cyclic hydrogen bond arrays: vibrational spectroscopic study of aminomethyl‐substituted resorcinarene‐based cavitands and their clathrates with THF

“…3 Later, FTIR spectroscopy was used to characterize host-guest complexes of calixarenes [8][9][10] and resorcarene-based cavitands [11][12][13] in the solid state and in solution, especially with a focus on hydrogenbonded [14][15][16][17] or surface-bound systems. 18,19 Resorcinarene-based cavitands 1 and 2 (Scheme 1) seem to be predestined for inter-and intramolecular hydrogen bonds and also show a rich host-guest chemistry. 20 Therefore, we decided to use FTIR spectro-scopy to study in cavitands 1 and 2 the weak supramolecular interactions which have a formative influence on the supramolecular, three-dimensional structure.…”