Lehrstuhl für Festkörperphysik, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstraße 7, 91058 Erlangen, Germany.
J Chem Phys. 2017 Feb 14;146(6):064702. doi: 10.1063/1.4975229.
Using x-ray photoemission spectroscopy, we investigated the self-metalation of free-base tetraphenylporphyrin (2HTPP) on thin MgO(100) films on Ag(100). The deposition of one monolayer 2HTPP on MgO results in the formation of magnesium(ii) tetraphenylporphyrin (MgTPP) at room temperature. We demonstrate that the efficiency of the reaction drastically depends on the morphology of the oxide layers. The latter is changed by varying the substrate temperature during the oxide growth. We observe the complete metalation of the 2HTPP monolayer when the MgO films are grown at 393 K. The increase of the growth temperature to 573 K leads to the reduction of the percentage of metalated molecules to ∼50%. We ascribe these results to the fact that MgTPP formation takes place through the hydroxilation of steps and defects on the MgO surface, which leads to an increase of the OH component in the O 1s line.
使用 X 射线光电子能谱,我们研究了自由碱基四苯基卟啉(2HTPP)在 Ag(100)上的 MgO(100)薄膜上的自金属化。在室温下,将一层 2HTPP 沉积在 MgO 上,会形成镁(ii)四苯基卟啉(MgTPP)。我们证明,反应的效率极大地取决于氧化物层的形态。后者通过在氧化物生长过程中改变基底温度来改变。当 MgO 薄膜在 393 K 下生长时,我们观察到 2HTPP 单层的完全金属化。将生长温度提高到 573 K 会导致金属化分子的百分比降低到约 50%。我们将这些结果归因于这样一个事实,即 MgTPP 的形成是通过 MgO 表面的台阶和缺陷的羟化作用发生的,这导致了 O 1s 线中 OH 成分的增加。