Solvophobic effects, self-assembly

It is general considered that the driving force for the self-assembly of amphiphilic molecules is a solvophobic effect, more specific in an aqueous environment, this is referred to as the hydrophobic effect. The type of aggregate morphology formed can be predicted... 

A self-assembled coordination cage and micelles were found to accelerate Diels-Alder reactions in an aqueous media. The catalysis of Diels-Alder reactions via noncovalent binding by synthetic, protein, and nucleic acid hosts has been surveyed and compared to explore the origin of the noncovalent catalysis. These catalysts consist of binding cavities that form complexes containing both the diene with the dienophile and the reaction occurring in the cavity. The binding requires no formation of covalent bonds and is driven principally by the hydrophobic (or solvophobic) effect. ... 

The LMWGs have in common the property that they self-assemble into fibrous aggregates a process that can be driven by different noncovalent interactions like coulomb interactions, hydrogen bonding, n-n interactions, van der Waals forces, and solvophobic effects. For most of the early examples of LMWGs, the gelation prop-... 

Alternatively, the level of stmctural complexity may be affected in a totally different manner employing co-assembly of chemically unlike molecules instead of self-assembly of chemically identical molecules [12-20]. We refer to the resultant micelles as mixed micelles or co-micelles to indicate that this type of micelle consists of more than one type of molecule, whereas classical micelles consist of identical molecules (polydispersity effects not taken into account). Consider two chemically distinguishable amphiphilic molecules A-B and C-D. Self-assembly into A/C or B/D micelles consisting of a core-shell structure, with a core solely consisting of A or C units and a shell solely consisting of B or D units, will only occur if the A or C units are solvophobic and the B or D units are solvophilic. However, if all units (A and B, or C and D) are solvophobic, phase separation will occur on a macroscopic level and result in a macroscopically inhomogeneous two-phase system. Conversely, if all units (A and B, or C and D) are solvophilic, phase separation... 

Self-assembling systems selectively produce the most thermodynamically stable products and therefore both the enthalpic and entropic contributions towards the final species must be considered. The formation of a self-assembled product, by definition, necessitates the formation of new, favourable interactions, i.e. the process is enthalpically favourable. However, the formation of aggregate species occurs at an entropic cost as many degrees of freedom in the system are lost. The entropic penalty is offset somewhat by the release of solvent molecules that were previously interacting with the binding areas of the assembly components, in a solvophobic effect (see Chapter 1, Section 1.3.5). 

The integration of molecular-recognition-directed self-assembly and chemistry of bilayer membranes has lead to the development of mesoscopic supramolecular assemblies. The impartment of amphiphilicity to supermolecules drives their hierarchical self-assembly. The solvophilic-solvophobic interactions play a pivotal role in the determination of the supramolecular architecture, and this is a distinct feature from the earlier supramolecular chemistry. The combinatorial supramolecular approach is also effective to develop functional mesoscopic assemblies. In addition, combination of supramolecular polymers and solvent engineering will give a new perspective in the design of mesoscopic materials. 

Greaves TL, Drummond CJ (2013) Solvent nanostructure, the solvophobic effect and amphi-phile self-assembly in ionic liquids. Chem Soc Rev 42 1096-1120... 

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