التفاصيل البيبلوغرافية
العنوان: |
Investigating the molecule-substrate interaction of prototypic tetrapyrrole compounds: Adsorption and self-metalation of porphine on Cu(111). |
المؤلفون: |
Diller, K., Klappenberger, F., Allegretti, F., Papageorgiou, A. C., Fischer, S., Wiengarten, A., Joshi, S., Seufert, K., Écija, D., Auwärter, W., Barth, J. V. |
المصدر: |
Journal of Chemical Physics; 4/21/2013, Vol. 138 Issue 15, p154710, 9p, 1 Color Photograph, 1 Diagram, 4 Graphs |
مصطلحات موضوعية: |
TETRAPYRROLES, METALATION, COPPER surfaces, X-ray photoelectron spectroscopy, X-ray absorption near edge structure, SUBSTRATES (Materials science), CHARGE exchange, SCANNING tunneling microscopy |
مستخلص: |
We report on the adsorption and self-metalation of a prototypic tetrapyrrole compound, the free-base porphine (2H-P), on the Cu(111) surface. Our multitechnique study combines scanning tunneling microscopy (STM) results with near-edge X-ray absorption fine-structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS) data whose interpretation is supported by density functional theory calculations. In the first layer in contact with the copper substrate the molecules adsorb coplanar with the surface as shown by angle-resolved NEXAFS measurements. The quenching of the first resonance in the magic angle spectra of both carbon and nitrogen regions indicates a substantial electron transfer from the substrate to the LUMO of the molecule. The stepwise annealing of a bilayer of 2H-P molecules sequentially transforms the XP and NEXAFS signatures of the nitrogen regions into those indicative of the coordinated nitrogen species of the metalated copper porphine (Cu-P), i.e., we observe a temperature-induced self-metalation of the system. Pre- and post-metalation species are clearly discriminable by STM, corroborating the spectroscopic results. Similar to the free-base porphine, the Cu-P adsorbs flat in the first layer without distortion of the macrocycle. Additionally, the electron transfer from the copper surface to the molecule is preserved upon metalation. This behavior contrasts the self-metalation of tetraphenylporphyrin (2H-TPP) on Cu(111), where both the molecular conformation and the interaction with the substrate are strongly affected by the metalation process. [ABSTRACT FROM AUTHOR] |
|
Copyright of Journal of Chemical Physics is the property of American Institute of Physics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) |
قاعدة البيانات: |
Complementary Index |