| Autor: |
Yuanhao Lyu, Feng Gao, Peng Cheng, Lan Chen, Svetlana Klyatskaya, Mario Ruben, Johanna Rosen, Johannes V. Barth, Jonas Björk, Kehui Wu, Yi‐Qi Zhang |
| Jazyk: |
angličtina |
| Rok vydání: |
2024 |
| Předmět: |
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| Zdroj: |
Advanced Materials Interfaces, Vol 11, Iss 26, Pp n/a-n/a (2024) |
| Druh dokumentu: |
article |
| ISSN: |
2196-7350 |
| DOI: |
10.1002/admi.202400222 |
| Popis: |
Abstract On‐surface reactions of terminal alkynes in ultrahigh vacuum have attracted widespread attention due to their high technological promise. However, employing different precursors and substrate materials often intricate reaction schemes appear far from being well‐understood. Thus, recent investigations of alkyne coupling on noble metal surfaces suggest non‐dehydrogenative scenarios, contradicting earlier reports. Herein, the study employs noncontact atomic force microscopy (nc‐AFM) with high spatial resolution to conclusively characterize exemplary alkyne coupling products. Contrary to initial interpretations proposing dehydrogenative homocoupling on Ag(111), bond‐resolved AFM imaging reveals the expression of enyne motifs. Based on complementary, extensive density functional theory calculations, the pertaining reaction mechanisms are explored. It is proposed that enyne formation initiates with a direct carbon–carbon coupling between two alkyne groups, followed by surface‐assisted dehydrogenation‐hydrogenation processes. Thereby consecutive steps of atomic hydrogen cleavage, surface migration and recombination to a different carbon atom enable bridging via carbon–carbon double bonding. The new results shed light on subtle, but crucial surface‐mediated hydrogen transfer processes involved in the chemical bond formation, which are suggested to be of general relevance in on‐surface synthesis. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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