We report the on-surface synthesis of a nonmetal porphyrin, namely, silicon tetraphenylporphyrin (Si-TPP), by the deposition of atomic silicon onto a free-base TPP layer on a Ag(100) surface under ultrahigh vacuum (UHV) conditions. Scanning tunneling microscopy provides insights into the self-assembly of the TPP molecules before and after Si insertion. Silicon coordinates with all four nitrogen atoms of the TPP macrocycle and interacts with a silver atom of the substrate as confirmed by scanning tunneling spectroscopy, X-ray photoelectron spectroscopy, and complementary density functional theory calculations. The Si-TPP complex presents a saddle-shaped conformation that is stable under STM manipulation. Our study shows how protocols established for the on-surface metalation of tetrapyrroles can be adopted to achieve nonmetal porphyrins. Complementary experiments yielding Si-TPP and Ge-TPP on Ag(111) highlight the applicability to different main group elements and supports. The success of our nonmetal porphyrin synthesis procedure is further corroborated by a temperature-programmed desorption experiment, revealing the desorption of Ge-TPP. This extension of interfacial complex formation beyond metal elements opens promising prospects for new tetrapyrrole architectures with distinct properties and functionalities.

中文翻译：

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非金属卟啉的表面合成

我们报告了通过在超高真空 (UHV) 条件下将原子硅沉积到 Ag(100) 表面上的游离碱 TPP 层上，在表面合成非金属卟啉，即硅四苯基卟啉 (Si-TPP)。扫描隧道显微镜可以深入了解硅插入前后 TPP 分子的自组装。扫描隧道光谱、X 射线光电子光谱和互补密度泛函理论计算证实，硅与 TPP 大环的所有四个氮原子配位并与基底的银原子相互作用。Si-TPP 复合物呈现出在 STM 操作下稳定的鞍形构象。我们的研究显示了如何采用为四吡咯表面金属化建立的协议来实现非金属卟啉。在 Ag(111) 上产生 Si-TPP 和 Ge-TPP 的互补实验突出了对不同主族元素和载体的适用性。我们的非金属卟啉合成程序的成功得到了程序升温解吸实验的进一步证实，揭示了 Ge-TPP 的解吸。这种超越金属元素的界面复合物形成的扩展为具有独特性质和功能的新型四吡咯结构开辟了广阔的前景。