Nevertheless, all pathways of dioxane and naphthalene shared the three common steps of the Octacid4•xylene pathways (Figs. and) except for more profound collisions of dioxane or naphthalene with the equatorial portal than those of xylene in the first step (Movies S7-S10) and subtle differences in the second step noted as follows. For dioxane, the second step involved the passing of the dioxane oxygen through the equatorial portal during which the oxygen was in the energetically less stable half-chair conformation, then the four-methylene portion of dioxane through the portal during which the methylene portion was in the energetically stable chair conformation, and lastly the other dioxane oxygen through the portal during which the oxygen was again in the half-chair conformation (Figs. and and Movies S7-S8). Interestingly, the Octacid4•dioxane self-assembly process followed the mutually induced fitting mechanism that is akin to the mechanism for the synthetic complex reported by Sawada et al. . For naphthalene, the passing of the two head b-carbon atoms, then the a-carbon portion, and finally the tail b-carbon atoms of the guest through the host portal was completed at the second step (Fig. and Movies S9-S10).