The local adsorption geometry and electronic structure of alanine on Cu{110}
The local adsorption geometry and electronic structure of alanine on Cu{110}
复制标题
DOI：
10.1016/j.susc.2006.02.033
复制
发表时间：
2006-05-01
期刊：
影响因子：
1.9
通讯作者：
Held, G.
中科院分区：
文献类型：
--
作者：
Jones, G.;Jones, L. B.;Held, G.
采用近边x射线吸收精细结构（NEXAFS）光谱、x射线光电子能谱（XPS）和密度泛函理论（DFT）相结合的方法研究了丙氨酸在Cu{110}上的吸附。在丙氨酸多层膜和化学吸附的[图形]和伪（3 × 2）丙氨酸层之间发现了较大的c1s、n1s和o1s XP光谱的化学位移。从C、N和O k壳层的NEXAFS光谱中，可以确定羧酸基的倾斜角度（相对于[1 (1)/ bar0]在平面上约为26度，平面外约为45度）和C-N键相对于[1 (1)/ bar0]的角度。利用这些信息，可以从5个p（3 × 2）结构中消除3种吸附几何形状，这些结构在DFT计算中导致几乎相同的吸附热在1.40和1.47 eV/分子之间。由于其余两种结构之间的能量差很小，它们在室温下共存于表面是不可能的。(c) 2006 Elsevier B.V.版权所有
The adsorption of alanine on Cu {110} 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[GRAPHICS]and pseudo-(3 x 2) alaninate layers. From C, N, and O K-shell NEXAFS spectra the tilt angles of the carboxylate group (approximate to 26 degrees in plane with respect to [1 (1) over bar0] and approximate to 45 degrees out of plane) and the C-N bond angle with respect to [1 (1) over bar0] could be determined for the pseudo-(3 x 2) overlayer. Using this information three adsorption geometries could be eliminated from five p(3 x 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. (c) 2006 Elsevier B.V. All rights reserved.