کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5425770 | 1395865 | 2006 | 12 صفحه PDF | دانلود رایگان |

The adsorption of alanine on Cu{1 1 0} was studied by a combination of near edge X-ray absorption fine structure (NEXAFS) spectroscopy, X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT). Large chemical shifts in the C 1s, N 1s, and O 1s XP spectra were found between the alanine multilayer and the chemisorbed 2-253 and pseudo-(3 Ã 2) alaninate layers. From C, N, and O K-shell NEXAFS spectra the tilt angles of the carboxylate group (â26° in plane with respect to [11¯0] and â45° out of plane) and the C-N bond angle with respect to [11¯0] could be determined for the pseudo-(3 Ã 2) overlayer. Using this information three adsorption geometries could be eliminated from five p(3 Ã 2) structures which lead to almost identical heats of adsorption in the DFT calculations between 1.40 and 1.47 eV/molecule. Due to the small energy difference between the remaining two structures it is not unlikely that these coexist on the surface at room temperature.
Journal: Surface Science - Volume 600, Issue 9, 1 May 2006, Pages 1924-1935