hydrogen bond thus appears to play an important role in modulating the slipped-stacking of molecules of 2. The non-fluorinated analog of 1, dehydrobenz [18]annulene 6, was previously synthesized. While the two compounds and the esterified analog 2 have very similar molecular structures, their packing arrangements differ quite profoundly. The crystal structure of 6 is held together by four T-shaped arene interactions between a hydrogen and a carbon of another arene (Figure ) with only short contact of 2.87(3) Å, whereas the fluorinated analogs 1 and 2 form slipped parallel stacks via fluoroarene-alkyne and arene-alkyne [π•••π] interactions in the case of 1 (Figure ), and hydrogen bonding, fluoroarene-fluoroarene and alkyne-alkyne [π•••π] interactions in the case of 2 (Figure ). The fluorination thus plays a critical role in forcing columnar assembly of macrocycles 1 and 2. shows several examples. In the co-crystal of octafluoronaphthalene and diphenylacetylene (Figure ), alternate stacks form between two molecules via the fluoroarene-alkyne interactions with short contacts of 3.32(2) Å. Similarly, as shown in Figure , the structure of the co-crystal of 4,4-diphenylethynyl-2,2-bipyridine with hexafluorobenzene also shows that the fluoroarene is not interacting with the benzene ring but with the acetylenic moiety. Fluorinated bistolane derivate shown in Figure also shows continuous stacking led by the π-interaction between a fluoroarene and an alkyne instead of the fluoroarene-arene interactions. Several additional examples show the presence of the fluroarenealkyne interaction despite the presence of an arene moiety available for a possible fluoroarene-arene interaction. This situation is observed in organic compounds, as well as in some of the metal complexes, although not many studies aimed to explain the observed patterns. The preference for the fluoroarene-alkyne interaction over the fluoroarene-arene interaction has also been observed in macrocyclic structures. For example, Bunz and co-workers observed that the cocrystal of hexafluorobenzene and the cyclic dimer of orthodiethynylbenzene shows a stacking pattern in which hexafluorobenzene centers above the alkyne moieties rather than the benzene rings of the macrocycle. Tahara and co-workers have synthesized the functionalized triangular dehydrobenzo [12]annulenes and observed that the fully fluorinated macrocycle stacks via fluoroarene-alkyne interactions. The same fluorinated DBA showed the fluoroarene-arene interaction when co-crystalized with the triply N,N-dimethylamino-substituted dehydrobenz [12]annulene. Moore and coworkers have concluded that the π-interactions between arenes and alkynes are not significantly stabilizing in DBAs. 7a However, fluorinating the arene may change this conclusion; the above-mentioned linear synthons, macrocycles, and our macrocycle 1 show that the fluoroarenes prefer to engage into the [π•••π] interaction with the alkyne moieties even in the presence of arenes within the molecule available for a potential fluoroarenearene interaction.