Beilstein J. Org. Chem.2018,14, 1937–1943, doi:10.3762/bjoc.14.167
alkyl chain rings, and formed a self-inclusion structure in aqueous media, which was assigned as a pseudo[1]catenane structure. The hydrophobic chain ring was hidden inside the pillar[5]arene cavity in the pseudo[1]catenane structure, thus the bicyclic compound was soluble in water at 20 °C with a
clouding point at 24 °C. The pseudo[1]catenane was converted to the de-threaded structure upon addition of the neutral guest 1,4-dicyanobutane, which displaced the alkyl chain ring from the inside to the outside of the cavity. The hydrophobic alkyl chain ring was now exposed to the aqueous media, causing
aggregation of the hydrophobic alkyl chain rings, which induced insolubilization of the bicyclic compound in aqueous media at 20 °C and a decrease in its clouding point.
Keywords: amphiphilic molecules; host–guest complexes; lower critical solution temperature; pillar[n]arenes; pseudo[1]catenane
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Graphical Abstract
Figure 1:
Chemical structures of (a) tri(ethylene oxide)-substituted pillar[n]arenes (1, n = 5; 2, n = 6), (b...