Noncovalent supramolecular

From the viewpoint of supramolecular chemistry, behavior of noncovalent supramolecular assemblies confined in mesopores would be a more interesting target. Aida and coworkers reported the first example of immobilization of one-dimensional columnar charge-transfer (CT) assemblies in a mesoporous silica film through sol-gel... 

The exploitation of the high specificity of the hydrogen-bonding systems, combined with their dynamic features has opened a new branch in polymer science dynamic materials with self-selection processes. This field, opened up by J.M. Lehn with his dynamers is highly prospective for the generation of new materials with properties unachievable with conventional monomers and polymeric materials, relying purely on the covalent bond, instead of the noncovalent, supramolecular interaction. 

These noncovalent supramolecular systems are stabilized via a mechanical interlocking that prevents the components from disassembling. A common precursor... 

Pseudorotaxane is produced when the linear molecule of the object penetrates the cyclic subject. While functional groups or compositions are attaching both ends of the object through the covalent bond or coordinate bond, the formation of a stopper shape blocks the separation of pseudorotaxane from the main body, generating rotaxane. Rotaxane and pseudorotaxane are both supramolecules maintained by the weak interaction of noncovalent bonds. The imit molecule determines the properties of the whole large molecule. The rotaxane is composed of a linear molecule and a cyclic molecule. N-rotaxane is formed when a linear molecule passes through n-1 cyclic molecules. Due to the special noncovalent supramolecular structure, this sort of supramolecule demonstrates the special character and has potential for application [48]. 

In comparison to abundant examples of noncovalent supramolecular assemblies,relatively few structures have been built with strong covalent bonds. This is due to the fact that normal covalent bonds are not easily broken and reformed. One can manipulate the temperature and conditions so that the formation of stable imines, esters, disulfides, hydrazones, and boronate esters is reversible. Some examples of these covalent self-assembled systems include disulfide hosts and covalent organic frameworks. ... 

A second class of lipid derivatives that contained two hydrophobic chains and a NTA polar head group was synthesized the double lipidic chain contained 12 (DC-12), 14 (DC-14), 16 (DC-16), and 18 (DC-18) carbon atoms. Unlike the single-chained (sc) class of molecules, no supramolecular assembly was observed for the double-chained (dc) reagents upon direct sonication with CNTs. Moreover, unlike the SC class, these reagents were not water soluble and formed vesicles in aqueous solutions. To ascertain whether micelles were required for supramolecular assembly formation, MWNTs were sonicated in the presence of DC compounds and a 1% concentration of the surfactant SDS. A mixed micelle consisting of DC/SDS formed in the aqueous solution SDS was subsequently removed through dialysis. TEM (see Transmission Electron Microscopy (TEM), Techniques) showed the formation of half-cylinder striations that were approximately 5.5-7.5nm, which was in agreement with the size of the different lipidic chains the striations were >4.5 nm, which implied that they were not due to SDS. Therefore, the formation of micelles appears to be the key step for the formation of noncovalent supramolecular assemblies on CNTs. 

A wide range of noncovalent supramolecular interactions such as hydrogen bonding, hydrophobic effect, aromatic 7Z-7Z Stacking, and metal-ligand coordination have been employed to construct template-directed [2]rotaxanes. 

Contributions from various noncovalent, supramolecular interactions are present in both low molecular weight and polymeric organic materials. Even conventional macromolecules, stabilized by mainchain covalent bonds as originally described by Staudinger, display a variety of supramolecular effects that control their intramolecular conformation and their intermolecular interactions. The selection of systems to be included in a book on supramolecular polymers was therefore a delicate task. 

Research on supramolecular polymers represents a central theme in supramolecular science [1], From a fundamental standpoint, one-dimensional supramolecular fiber is the simplest supramolecular motif and serves as an analog of covalent polymeric chains. Noncovalent supramolecular polymers have two main advantages in comparison with their covalent counterparts they are easy to make using self-assembly and they are adaptive, i.e., capable of structural changes and depolymerization by external stimuli [1]. However, these attractive properties present key challenges related to robustness and rational design noncovalent interactions result in relatively weak bonds, whereas multiple molecular units and interaction modes render synthesis of predesigned structures very difficult. 

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