Department of Physics, Norwegian University of Science and Technology, Høgskoleringen 5, NO-7491 Trondheim, Norway.
J Phys Condens Matter. 2010 Oct 6;22(39):395004. doi: 10.1088/0953-8984/22/39/395004. Epub 2010 Sep 10.
Methylamine adsorption on the ordered Ni(3)Al(111) and NiAl(110) surfaces has been investigated by high resolution photoelectron spectroscopy and density functional theory calculations. Methylamine adsorbs molecularly at both surfaces at low temperature (90 K). The experiments show that methylamine interacts with the surface aluminium atoms on both surfaces, resulting in a positive binding energy shift relative to the Al 2p bulk contributions. A shift towards lower binding energy is also observed on NiAl(110) attributed to first and second layer surface Al atoms not bonded to methylamine. According to total energy calculations methylamine binds through its N atom to Al on-top sites on NiAl(110) while the Ni on-top site is found to be slightly preferred over the Al on-top site on Ni(3)Al(111). Calculated adsorbate induced shifts are, however, in good agreement with the experimental values only when methylamine is situated in the Al on-top site on both surfaces. In both cases, a lone pair bonding mechanism is found.
采用高分辨率光电子能谱和密度泛函理论计算研究了甲胺在有序 Ni(3)Al(111)和 NiAl(110)表面上的吸附。甲胺在低温（90 K）下在两个表面上以分子形式吸附。实验表明，甲胺与两个表面上的表面铝原子相互作用，导致相对于 Al 2p 体相贡献的结合能正移。在 NiAl(110)上也观察到向更低结合能的位移，这归因于未与甲胺键合的第一层和第二层表面 Al 原子。根据总能量计算，甲胺通过其 N 原子与 NiAl(110)上的 Al 顶位结合，而在 Ni(3)Al(111)上，Ni 顶位略微优先于 Al 顶位。然而，只有当甲胺位于两个表面上的 Al 顶位时，计算出的吸附诱导位移才与实验值非常吻合。在这两种情况下，都发现了孤对键合机制。
