THE ADSORPTION GEOMETRY OF BENZOIC ACID ON Ni(110)

The adsorption geometry of benzoic acid on Ni(110) was investigated by X-ray photoelectron spectroscopy, angle-resolved near edge X-ray absorption fine structure spectroscopy at the C1s and O1s excitation edges, and thermal desorption spectroscopy. At a substrate temperature of 360 K and saturation coverage the adsorbate forms a benzoate with molecules adsorbed on the surface via two equivalent oxygen atoms. For this dense adsorbate layer the molecular plane was found to be azimuthally rotated by about ± 30° with respect to the [Formula: see text] surface azimuth and tilted by ≈ 30° with respect to the surface normal. At about half the saturation coverage some rearrangement of molecules occurs in such a way that their planes become directed along the [001] surface direction, which is different from the adsorption geometry observed after annealing the saturated layer. At even smaller coverage the benzoate molecules appear to adsorb with their molecular planes nearly parallel to the surface. Semiempirical quantum-mechanical cluster calculations indicate that the carboxylate oxygens favor the highly coordinated sites in the [Formula: see text]-oriented troughs of the Ni(110) surface. Possible adsorption models are discussed.

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Triptycene-terminated thiolate and selenolate monolayers on Au(111)

Beilstein Journal of Nanotechnology ◽

10.3762/bjnano.8.91 ◽

2017 ◽

Vol 8 ◽

pp. 892-905 ◽

Cited By ~ 5

Author(s):

Jinxuan Liu ◽

Martin Kind ◽

Björn Schüpbach ◽

Daniel Käfer ◽

Stefanie Winkler ◽

...

Keyword(s):

Binding Energy ◽

Photoelectron Spectroscopy ◽

High Vacuum ◽

Thermal Desorption Spectroscopy ◽

Ultra High Vacuum ◽

Self Assembled Monolayers ◽

X Ray ◽

Infrared Reflection ◽

Assembled Monolayers ◽

X Ray Absorption

To study the implications of highly space-demanding organic moieties on the properties of self-assembled monolayers (SAMs), triptycyl thiolates and selenolates with and without methylene spacers on Au(111) surfaces were comprehensively studied using ultra-high vacuum infrared reflection absorption spectroscopy, X-ray photoelectron spectroscopy, near-edge X-ray absorption fine structure spectroscopy and thermal desorption spectroscopy. Due to packing effects, the molecules in all monolayers are substantially tilted. In the presence of a methylene spacer the tilt is slightly less pronounced. The selenolate monolayers exhibit smaller defect densities and therefore are more densely packed than their thiolate analogues. The Se–Au binding energy in the investigated SAMs was found to be higher than the S–Au binding energy.

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FORMATION OF ORDERED MOLECULAR OVERLAYERS BY A TEMPERATURE-INDUCED SURFACE REACTION: HEXABUTYLOXYTRIPHENYLENE ON Cu(111)

Surface Review and Letters ◽

10.1142/s0218625x99000214 ◽

1999 ◽

Vol 06 (02) ◽

pp. 183-192 ◽

Cited By ~ 5

Author(s):

H. WEGNER ◽

K. WEISS ◽

CH. WÖLL

Keyword(s):

Chemical Reaction ◽

Photoelectron Spectroscopy ◽

Room Temperature ◽

Thermal Desorption Spectroscopy ◽

Scanning Tunneling ◽

Tunneling Microscopy ◽

X Ray ◽

Molecular Monolayers ◽

Disordered Layer ◽

X Ray Absorption

Molecular monolayers obtained by the adsorption of hexabutyloxytriphenylene (HBT) on Cu (111) were investigated by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and thermal desorption spectroscopy (TDS). Adsorption at room temperature results in the formation of a disordered layer of physisorbed molecules. Annealing at temperatures of 600 K is found to induce a chemical reaction of the molecule with the substrate, leading to a desorption of the butyl fragments. This chemical reaction is accompanied by the formation of a highly ordered, well-defined oxytriphenylene layer which is stable for temperatures of up to 600 K.

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