Radical-promoted room-temperature terminal alkyne activation on Au (111)

Exploring on-surface reactions of terminal alkyne derivatives are of primary importance for controlled synthesis of graphyne and graphdiyne-type materials. In this study, room-temperature (RT) adsorption of ethynylphenanthrene (EP) and ethynyl-iodophenanthrene (EIP) precursors on Au(111) were investigated by combined scanning tunneling microscopy and density functional theory (DFT) modeling. In contrast to inert adsorption of EP on Au(111), RT deposited EIP molecules are partially deiodinated, which gives rise to various kinds of reaction products. Surprisingly, polymeric chains with length up to similar to 15 nm were identified. Our DFT modeling evidences that the alkyne activation and covalent coupling on Au(111) are more favored for the deiodinated precursors.

Automated summary

In this study, the adsorption behavior of ethynylphenanthrene (EP) and ethynyl-iodophenanthrene (EIP) precursors on Au(111) was investigated using scanning tunneling microscopy and density functional theory (DFT) modeling. It was found that the partially deiodinated EIP molecules can undergo various reactions, including the formation of polymeric chains up to a length of approximately 15 nm. DFT modeling suggests that the deiodinated precursors favor alkyne activation and covalent coupling on Au(111).