Conformer-Selective Adsorption of 1-Propanol on the Ag(111) Surface

Abstract

Reflection absorption infrared spectra (RAIRS) were simulated with density functional theory calculations for five different rotational conformers of 1-propanol on the Ag(111) surface for comparison to the corresponding experimental spectra. The experimental RAIR spectra were obtained by adsorbing multilayers of 1-propanol at 90 K and then annealing the surface to 180 K to desorb the multilayer and produce the most stable 1-propanol monolayer structure on Ag(111). The multilayer spectrum features a broad O–H stretch characteristic of hydrogen bonding between the molecules as well as broad and complex peaks in the C–H stretch and C–H deformation regions. After annealing to 180 K, the O–H stretch peak disappears, and the remaining peaks are unusually sharp. Comparison of the experimental and simulated spectra indicates that 1-propanol adsorbs as only one of the five conformers.

Conformer-Specific Desorption in Propanol Ices Probed by Chirped-Pulse Millimeter-Wave Rotational Spectroscopy

“…In addition to these gas-phase measurements, DFT computational studies applied to understand the results of experimental work employing reflection absorption infrared spectra to study 1propanol deposited on a Ag(111) surface reveal that only one of the five conformers of 1-propanol adsorbs. 4 This Letter reports our first new scientific insight, whereas our previous paper described the buffer gas cell and spectrometer. A forthcoming paper will describe ice generation, electron irradiation, and detection of the resulting product species following temperature-programmed desorption (TPD).…”

“…They observed significant differences in the relaxation cross sections for 1,2-propanediol. In addition to these gas-phase measurements, DFT computational studies applied to understand the results of experimental work employing reflection absorption infrared spectra to study 1-propanol deposited on a Ag(111) surface reveal that only one of the five conformers of 1-propanol adsorbs …”

Adsorption of acrolein and its hydrogenation products on Cu(111)

“…On the Ag(111) surface, we attributed the simplicity of the spectrum consisting of just a few extremely sharp peaks to the presence of only one of the five possible conformers of 1-propanol on the surface. 33 While the 160 and 180 K anneals have a somewhat similar effect on the spectra for 1-propanol on Cu(111), the evidence for the presence of only one conformer is not as compelling due to the greater number of peaks, particularly in the region below 1100 cm À1 , and their higher FWHM. The 180 K spectrum in Fig.…”