Carbon-sulfur compounds [1] have been studied extensively as key materials in organic/molecular electronics. A variety of poly-and oligothiophenes have been synthesized by organic synthesis and electrochemistry to elucidate their electronic properties. [2][3][4] TTF (= 1,4,5,8-tetrathiafulvalene) is a very important molecular skeleton as a donor for organic metals and superconductors; (7,7,8,8-tetracyanoquinodimethane)] was the first organic metal to be developed into organic superconductors in the salts of TMTSF (= tetramethyltetraselenafulvalene), BEDT-TTF (bis(ethylenedithio)tetrathiafulvalene). [5] In these materials, intermolecular SโขโขโขS contacts play a crucial role in bringing about multidimensional electronic structures that are advantageous to electrical conduction. Cyclic oligothiophenes and thiocirculenes possess promising molecular structures from this perspective; the sulfur atoms are exposed to the outside of the molecular rings. Intermolecular SโขโขโขS contacts are naturally expected in their crystals. In addition, their molecular structures are of considerable interest because they involve the radialene framework that has been a theoretical and experimental matter of concern with regard to exocyclic double bonds, aromaticity, and p-conjugation. [6][7][8][9][10][11][12][13] Recently, Nenajdenko et al. synthesized octathio[8]circulene (2) from the parent compound, tetrathiophene (1), and 2 named "sulflower". [14] They obtained 2 as a red powder and estimated molecular and crystal structures from powder X-ray diffraction data, concluding the presence of a closed packing structure in the solid state with short intermolecular SโขโขโขS contacts. [14] Although the synthesis of 2 has attracted much attention, there is no single-crystal X-ray analysis; the