Recently, the novel synthesis of supramolecular 2D sheet materials composed of a pillar[6]arene (a cyclic hexamer of p-arylenemethylene), driven by charge-transfer (CT) interaction between its hydroquinone form and its benzoquinone form was reported [1]. When the hydroquinone form of pillar[6]arene was oxidized with an oxidant in a methanol solution, a generated partially oxidized benzoquinone form underwent CT complex formation with its pristine form to 2D-assemble with a hexagonal packing, followed by further assembly to form fibrils. In order to control the size and shape of the material, we investigated the electrochemical oxidation of a pillar[6]arene, and resulted in the successful formation of uniform hexagonal cylinder structures on an electrode surface (Figure 1) [2].

[1] T. Ogoshi, K. Yoshikoshi, R. Sueto, H. Nishihara, T. Yamagishi, Angew. Chem. Int. Ed. 2015, 54, 6466-6469.

[2] C. Tsuneishi, Y. Koizumi, R. Sueto, H. Nishiyama, K. Yasuhara, T. Yamagishi, T. Ogoshi, I. Tomita, S. Inagi, Chem. Commun. 2017, 53, 7454-7456.