The electronic structure and adsorption geometry of L-histidine on Cu(110).
The adsorption of L-histidine on clean and oxygen-covered Cu(110) surfaces has been studied by soft X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The valence band spectra, carbon, nitrogen and oxygen 1 s XPS and N K edge absorption spectra were measured for submonolayer, monolayer, and multilayer films. The spectra provide a detailed picture of the electronic structure and adsorption geometry at each coverage. In the monolayer, the histidine molecules are randomly oriented, in contrast to the submonolayer regime, where the molecules are coordinated to the copper surface with the imidazole functional group nearly parallel to, and strongly interacting with, the surface. The pi*/sigma* intensity ratio in NEXAFS spectra at the nitrogen edge varies strongly with angle, showing the imidazole ring is oriented. Adsorption models are proposed.
Sincrotrone Trieste S.C.p.A., Area Science Park, Strada Statale 14, km 163.5, I-34012 Basovizza, Trieste, Italy. vitaliy.feyer@elettra.trieste.it
Vitaliy
V
Feyer
Oksana
O
Plekan
Tomás
T
Skála
Vladimír
V
Cháb
Vladimír
V
Matolín
Kevin C
KC
Prince
D000327:Adsorption; D000596:Amino Acids / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry; D008958:Models, Molecular; D010100:Oxygen / Q000737:chemistry; D014961:X-Ray Diffraction
D000596:Amino Acids; D007093:Imidazoles; D006639:Histidine; D003300:Copper; D010100:Oxygen