Identifying On-Surface Site-Selective Chemical Conversions by Theory-Aided NEXAFS Spectroscopy: The Case of Free-Base Corroles on Ag(111).
Identifying On-Surface Site-Selective Chemical Conversions by Theory-Aided NEXAFS Spectroscopy: The Case of Free-Base Corroles on Ag(111).
复制标题
DOI：
10.1002/chem.201705921
复制
发表时间：
2018-05
期刊：
影响因子：
--
通讯作者：
H. Aldahhak;M. Paszkiewicz;E. Rauls;F. Allegretti;S. Tebi;A. Papageorgiou;Yanmei Zhang;Liding Zhang;Tao Lin;T. Paintner;R. Koch;Wolf Gero Schmidt;J. Barth;W. Schöfberger;S. Müllegger;F. Klappenberger;U. Gerstmann
中科院分区：
文献类型：
--
作者：
H. Aldahhak;M. Paszkiewicz;E. Rauls;F. Allegretti;S. Tebi;A. Papageorgiou;Yanmei Zhang;Liding Zhang;Tao Lin;T. Paintner;R. Koch;Wolf Gero Schmidt;J. Barth;W. Schöfberger;S. Müllegger;F. Klappenberger;U. Gerstmann
我们在这里证明了理论辅助的近边缘x射线吸收精细结构（NEXAFS）光谱能够对表面化学反应进行现场敏感监测，从而提供其他技术无法获得的信息。作为一个原型例子，我们使用了吸附在Ag（111）上的游离碱5,10,15-三（五氟苯基）对应物（3H-TpFPC），并详细研究了该分子物种的角度依赖性NEXAFS及其热诱导衍生物。为此，我们记录了实验C和N k边缘NEXAFS光谱，并基于XAS横截面计算，使用连续分数方法和DFT内包含多投影仪PAW伪势的岩心孔来解释它们。我们对低温（200 K）沉积相进行了表征，并揭示了脱氢（330 K）和环闭合反应（430 K）引起的后续变化。通过举例获得对吸附在贵金属上的自由碱腐蚀物质的表面化学的深刻见解，这项工作强调了依赖角度的XAS与精确的理论建模相结合如何用于表面反应的研究，从而甚至可以区分高度相似的分子结构，如互变异构体和异构体。
We demonstrate here that theory-assisted near-edge X-ray absorption fine-structure (NEXAFS) spectroscopy enables the site-sensitive monitoring of on-surface chemical reactions, thus, providing information not accessible by other techniques. As a prototype example, we have used free-base 5,10,15-tris(pentafluorophenyl)corroles (3H-TpFPC) adsorbed on Ag(111) and present a detailed investigation of the angle-dependent NEXAFS of this molecular species as well as of their thermally induced derivatives. For this, we have recorded experimental C and N K-edge NEXAFS spectra and interpret them based on XAS cross-section calculations by using a continuous fraction approach and core-hole including multiprojector PAW pseudopotentials within DFT. We have characterized the as-deposited low temperature (200 K) phase and unraveled the subsequent changes induced by dehydrogenation (at 330 K) and ring-closure reactions (at 430 K). By exemplarily obtaining profound insight into the on-surface chemistry of free-base corrolic species adsorbed on a noble metal this work highlights how angle-dependent XAS combined with accurate theoretical modeling can serve for the investigation of on-surface reactions, whereby even highly similar molecular structures, such as tautomers and isomers, can be distinguished.