The self-assembly of well-defined 2D supramolecular polymers in solution has been a challenge in supramolecular chemistry. We have designed and synthesized a rigid stacking-forbidden 1,3,5-triphenylbenzene compound that bears three 4,4'-bipyridin-1-ium (BP) units on the peripheral benzene rings. Three hydrophilic bis(2-hydroxyethyl)carbamoyl groups are introduced to the central benzene ring to suppress 1D stacking of the triangular backbone and to ensure solubility in water. Mixing the triangular preorganized molecule with cucurbit[8]uril (CB[8]) in a 2:3 molar ratio in water leads to the formation of the first solution-phase single-layer 2D supramolecular organic framework, which is stabilized by the strong complexation of CB[8] with two BP units of adjacent molecules. The periodic honeycomb 2D framework has been characterized by various (1)H NMR spectroscopy, dynamic light scattering, X-ray diffraction and scattering, scanning probe and electron microscope techniques and by comparing with the self-assembled structures of the control systems.

Hydrogen-bonded capsules constrain molecules into small spaces, where they exhibit behavior that is inaccessible in bulk solution. Water competes with the formation of hydrogen bonds, and other forces for assembly, such as metal/ligand interactions or hydrophobic effects, have been applied. Here we report the reversible assembly of a water-soluble cavitand to a robust capsule host in the presence of suitable hydrophobic guests. The complexes are characterized by conventional NMR methods. Selectivity for guest length and fluorescence quenching of a stilbene guest are used as evidence for hydrogen bonding in the capsule.

We report here a widened, deep cavitand host that binds hydrophobic and amphiphilic guests in D2O. Small alkanes (C6 to C11) are bound in compressed conformations and tumble rapidly within the space. Longer n-alkanes (C13 to C14), n-alcohols, and α,ω-diols are taken up in folded conformations. The guests' termini are exposed to solvent while atoms near the alkane's center are buried and protected. The cavitand acts as a concave template that pushes terminal atoms of the guest closer together. The unexpected binding modes are interpreted in terms of the size and shape of the space accessible in the new cavitand.

The existence of three fully orthogonal dynamic covalent bonds is demonstrated in solution and in functional surface architectures.