Submonolayer growth of H 2 -phthalocyanine on Ag(111)
Submonolayer growth of H 2 -phthalocyanine on Ag(111)
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H 2 -酞菁在Ag(111)上的亚单层生长
DOI：
10.1103/physrevb.86.195412
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发表时间：
2012
影响因子：
3.7
通讯作者：
C. Kumpf
中科院分区：
文献类型：
--
作者：
Ingo Kröger;P. Bayersdorfer;B. Stadtmüller;C. Kleimann;G. Mercurio;F. Reinert;C. Kumpf
本文对H${}_{2}$-酞菁（H${}_{2}$Pc）在Ag（111）表面的吸附物体系的结构和电子性质进行了全面的研究。与铜酞菁（CuPc）在Ag（111）上的比较使我们能够阐明分子中的中心金属原子对吸附物-基底相互作用的影响。该金属原子是可以改变以改变酞菁分子的性质的一个基本参数，因此其对吸附行为的影响是高度相关的。从高分辨电子衍射，我们得到了一个亚单层覆盖的相图，结果是类似的CuPc/Ag（111）。最显著的区别是一个相称相的更高的稳定性，表明更强和更多的吸附位点特异性键的H${}_{2}$Pc分子。此外，紫外光电子能谱和X射线驻波证明分子和衬底之间的化学吸附相互作用和氮原子接近表面的分子的显着弯曲。我们的结论是，金属酞菁分子与Ag（111）的吸引力的相互作用主要是由分子的芳香体（特别是四氮杂卟啉环），而不是由中心的金属原子（在铜酞菁的情况下）已经显示泡利排斥介导的。
We present a comprehensive study of structural and electronic properties of the adsorbate system H${}_{2}$-phthalocyanine (H${}_{2}$Pc) on Ag(111). A comparison with copper-phthalocyanine (CuPc) on Ag(111) allows us to elucidate the impact of the central metal atom in the molecule on the adsorbate-substrate interaction. This metal atom is one fundamental parameter which can be changed in order to modify the properties of phthalocyanine molecules, and therefore its influence on the adsorption behavior is highly relevant. From high-resolution electron diffraction, we obtained a phase diagram for submonolayer coverages which turns out to be similar to that of CuPc/Ag(111). The most striking difference is a higher stability of a commensurate phase, indicating a stronger and more adsorption site-specific bonding of the H${}_{2}$Pc molecules. Furthermore, ultraviolet photoelectron spectroscopy and x-ray standing waves prove chemisorptive interaction between molecules and substrate and a significant bending of the molecules with the nitrogen atoms approaching the surface. We conclude that the attractive interaction of metal-phthalocyanine molecules with Ag(111) is mainly mediated by the aromatic body of the molecule (the tetraazaporphyrin ring in particular) rather than by the central metallic atom which (in the case of CuPc) already shows Pauli repulsion.