Hydrogen-bond interaction-driven coordination

In another example of hydrogen-bond interaction-driven coordination, Teixidor and Lledos have exploited C—H S—H H—B hydrogen/dihydrogen-bond... 

The adsorption of neutral molecules on smectites is driven by various chemical interactions hydrogen bonds, ion-dipole interactions, coordination bonds, acid-base reactions, charge transfer, and van der Waals forces. Several polar molecules, such as alcohols, amines, and acids, form intercalation complexes with montmorillonites. The intercalation can be performed from the vapor, liquid, or even solid state. In intercalation from solution, solvent molecules are generally coadsorbed in the interlayer space. Guest molecules may be intercalated in dried clay minerals or may displace the water molecules of hydrated montmorillonite. 

The construction of self-assembled capsules based on ionic interactions to be tested as supramolecular hosts in polar solvents such as alcohols or water is a timely goal that, compared to hydrogen-bonded capsules, is still in its infancy even though important steps have been taken. Few examples have been reported regarding ionic capsules between cationic fiat tetrapyridinium-Zn(II)-porphyrinate and anionic tetrasulfonate-calix[4]arenes that form a hemispherical entropy-driven capsule that displayed high stability in the presence of water or competing salts. Apart from solvent molecules, such capsules showed encapsulation of small guests like 1-methylimidazole or 4-methylpyridine via coordination to the Zn(II) metal... 

Self-assembly can also be induced by metal-ligand interactions [33,34], In this case, supramolecular coordination complexes that are thermodynamically favored products can be obtained from spontaneous metal—ligand bond formation in a mixture of soluble metal and ligand precursors [19]. These self-assembled capsules, which are known as coordination-driven self-assembly, are more robust than hydrogen bond capsules [13,35]. 

The self-assembling process involves noncovalent or weak interactions (van der Waals, electrostatic, and hydrophobic interactions, hydrogen and coordination bonds, and r-7T stacking). This process corresponds to a variation of reversed pore structures. Most ordered mesoporous materials are derived from the thermodynamically stable and ordered a regates spontaneously driven by the noncovalent interactions between molecules. These aggregates come from the cationic, anionic and nonionic surfactants, neutral amines, block copolymers, or their mixtures (Figure 13.1). They are disordered on the atomic or... 

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