The chiral cyclic [n]spirobifluorenylenes 2- [n] were synthesized by the Ni(0)-mediated Yamamoto coupling of chiral triflates (R or S)-3 (Scheme 1). After filtering through a short silica-gel column, the MALDI-TOF mass analysis of the product showed the formation of a mixture of cyclic oligomers up to a 9-mer (Figure ), although the dimer 2- [2] was not observed. The combined yield of 2-[3], 2-[4], and 2- [5] for the R isomer was 40% with the ratio of 1.0, 0.91, and 0.38, respectively. Figure shows the X-ray crystallographic structure of cyclic 3-mer (S,S,S)-2- [3], showing a D3 symmetry. The distance between the spirocarbon units is 9.0 Å. The distortion around the spirocarbon is minimal (89.5 °), but the internal benzene ring A is slightly distorted (up to 3.5 ° for 1). The dihedral angle between the spirobifluorene units is 43.0 °. The packing structure indicates that CH- interactions connect the molecules in a sideby side arrangement (Figure ). One-dimensional voids filled by solvent are formed by the stacking of the molecules. The crystal structure of the 4-mer (S,S,S,S)-2- [4] is shown in Figure . The observed structure did not show a D4 symmetric square but, instead, a D2 symmetric rectangle. The distances between the spirocarbons are 8.7 and 9.0 Å. The rectangle shape is derived from large difference in the torsion between the spirobifluolenes (50.1 ° and 4.2 °). The rectangle shape appears to be induced by guest solvents. However, the 1 H NMR spectrum in CDCl3 at room temperature shows only 7 peaks, indicating that the four spirobifluorene units are equivalent in solution (see Supporting Information). The packing structure also indicates that CH- interactions connect the molecules side by side (Figure ). One-dimensional voids filled by solvent are formed by the stacking of the molecules, similar to the 3-mer. The crystal structure of the 5-mer (S,S,S,S,S)-2- [5] has no symmetry, where a distorted structure was observed (Figure ). Concerning the distances between spirocarbons, a significantly short distance (8.3 Å) was observed in one of the five (the other four showed around 8.8-8.9 Å). Considerably small angles (86.6 ° and 86.7 °) between the planes around spirocarbon were also exhibited in two of the five (the angle for the unstrained ideal one is 90°). A large dihedral angle (84.2 °) between the fluorene units, which is almost orthogonal, was observed in one of the five (the other four showed in a range of 32-43 °). In addition, each fluorene plane is more or less tilted slightly. These features imply the inherent strain in the crystal structure of (S,S,S,S,S)-2- [5]. The packing structure is complicated, and the columnar stacking like and was not observed (Figures and). and.