Synthesis of Hexabenzocoronene-Cored Graphdiyne Nanosheets through Dehydrogenative Coupling on Au(111) Surface

LN Wang and Y Han and M Xie and XC Li and Q Chen and YN Tang and Y Liu and HT Ge and HL Li and LSH Cai and K Meerholz and HM Zhang and K Müllen and LF Chi, ANGEWANDTE CHEMIE-INTERNATIONAL EDITION, 63, e202411722 (2024).

DOI: 10.1002/anie.202411722

Thermally-induced dehydrogenative coupling of polyphenylenes on metal surfaces is an important technique to synthesize pi $\pi $ -conjugated carbon nanostructures with atomic precision. However, this protocol has rarely been utilized to fabricate structurally defined carbon nanosheets composed of sp- and sp2-hybridized carbon atoms. Here, we present the synthesis of butadiyne-linked hexabenzocoronenes (HBCs) on Au(111) surfaces as core-expanded graphdiynes. The reaction started from hexa(4-ethylphenyl)benzene, which undergoes dehydrogenation toward hexa(4-vinylphenyl)benzene, followed by planarization to hexabenzocoronene, coupling between the vinyl groups, and further dehydrogenation. In addition to butadiyne linkages, benzene groups were also found as another type of linker. The reaction sequences were monitored by scanning tunneling microscopy and bond-resolved non-contact atomic force microscopy, which disclose the structures of intermediates and final products. In combination with density functional theory simulations, the key steps from ethyl substituents to butadiyne and benzene linkers were elucidated. This is a new on-surface synthesis of core-expanded graphdiynes with unprecedented electronic properties.

Return to Publications page