Self-organized supramolecular structures

The latter example leads us to still another characteristic feature of supramolecular concepts i.e., their hierarchical assemblies allow functional materials. Functionality is regarded as one of the hallmarks of supramolecular science [13] as even in classical chemistry and self-organization, complexes, salts, etc. are formed due to chemical matching. One can point out that the borderline between classical chemistry and supramolecular chemistry is not strict. For example, in general block copolymers dissolved in block-selective solvents might not be regarded as supramolecular chemistry, whereas some of the more specific further developments [18, 82] clearly allow supramolecular functional materials, as will be shown in Section 3. 

In this section representative examples are introduced, which combine self-organization (as defined in Section 1) and supramolecular structure formation. The specific features in designing electrical properties will be discussed in the next section. 

Self-Organizfid Supnanolecular Structures of Pofymer-An h kUe Complexes 

Supramolecular comb block copolymers and Hairy Rods 

Zn(DBS)2 also yields self-organized complexes with selected other nitrogen-containing polymers. For example, complexing polyamide 6 stoichiometrically with Zn(DBS)2 yields self-organized lamellar structure with a long period of 28 A [112] as well as it forms complexes with polyaniline [113], as will be discussed later. 

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Metals of this group all form self-organized supramolecular structures via inter-molecular dative bonds. This tendency is strong for the elements in the upper part... 

The tendency of Tl - O bond formation, leading to self-organized supramolecular structures, is obvious in several instances of bridge formation between molecules which otherwise would contain four-coordinate thallium(III). Thus, two molecules of dimethylthallium(III) tryptophanate (with intramolecular Tl-O bonds of 2.468 A and long Tl - -N interactions of 3.434 A) dimerize via longer Tl- - -O secondary bonds (Tl- - -O 2.593 A) to form a central TFO four-membered moiety, 115 [340]. 

A beautiful self-organized supramolecular structure, 21, was found for methyl-mercury(II) diphenylmonothiophosphinate, MeHgSP(=0)Ph2 it is associated by Hg- - -O secondary bonding into quasi-cyclic dimers which are connected, again via... 

A particularly interesting type of self-organized supramolecular structure is observed for some half-sandwich organotin] II) halides. 

Bis(p-trimethylsilylphenyl)tellurium dichloride, (4-Me3SiC6H4)TeCl2, is another example of a self-organized supramolecular structure, 209 [496]. 

The ability of the polyelectrolytes to form self-organized supramolecular structures, together to their capacity to form complexes when polyelectrolytes of opposite charge are mixed are well-known phenomena, and they have been studied from... 

Organoclay materials with higher-order organization can also be prepared by template-directed methods involving self-assembled supramolecular structures. In this approach, preformed organic architectures in the form of tubes, fibers, hollow shells, gyroids, helicoids, and so on are transferred into hybrid materials exhibiting structural hierarchy, complex form and ordered mesoporosity [47-55]. For example,... 

Jprgensen et al. 141 utilized this molecular organization process (dumbbell-like stacking) to incorporate tetrathiafulvalene (TTF a substrate currently of interest in such areas as molecular electronics and organomagnetism) within the central lypophilic region (Scheme 4.33) of the self-assembled, supramolecular structures. A multistage synthesis... 

Increased functionality of the organometallic moiety will lead to more intricate supramolecular assemblies. A suggestive organometallic example is provided by tetra(p-cyanophenyl)silane, Si(C6H4CN-p)4, which forms a three-dimensional self -organized supramolecular network of interpenetrating double layers by coordination with silver ions [27] and a layered supramolecular structure with TiCU [28], both imposed by the directionality of tetrahedral silicon centers. Supramolecular assemblies are defined as "extended polymolecular arrays presenting a more or less... 

SELF-ORGANIZED SUPRAMOLECULAR POLYMER STRUCTURES TO CONTROL ELECTRICAL CONDUCTIVITY... 

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