On-surface synthesis recently enabled access to generate a series of cycloncarbons (Cn, up to C26) via delicately designed precursors. However, for larger cyclocarbons, synthesis of the corresponding precursors is being challenged. Here, we report another strategy for synthesizing larger cyclocarbons via the coupling and ring-opening reactions from smaller ones. We chose C10 as the precursor, and induce the coupling and ring-opening reactions via tip manipulation to successfully generate C20 and C30. Bond-resolved atomic force microscopy imaging unambiguously reveals the polyynic structure of C30, aligning with theoretical prediction. This approach establishes a new pathway to access larger cyclocarbons, and potentially enables controlled polymerization of cyclocarbons.
Guo et al. (Sat,) studied this question.