Internal and External Pockets in Pillarnarene Sheets and Their Host–Guest Binding Beyond Cavity Volume Limitations

Constructing binding pockets by hierarchically assembling tailored building blocks and understanding structure–property relationships are challenging goals. Herein, amphiphilic pillar5arene and pillar6arene were prepared and used to construct 2D sheets, which consisted of well-defined hydrophobic and hydrophilic interlayers. In the hydrophobic interlayers, internal hydrophobic pockets were created by packing pairs of pillar n arenes, and external hydrophobic pockets were simultaneously generated from gaps between pillar n arenes due to electrostatic attractions. Aromatic hydrocarbons were accommodated in these hydrophobic pockets by ball milling. Due to the external pockets, bulky guests larger than the pillar n arene cavity sizes were also captured in the sheets.