Self-assembly supramolecular

Upon supramolecular self-assembly, low molecular-weight additives can be used to adjust the properties of BC bulk films by hydrogen bonds. Ikkala and coworkers first introduced this concept in PS-fc-poly(4-vinylpyridine) (P4VP) stoichiometrically complexed with pentadecylphenol molecules to form the supramolecules by hydrogen bonding (Makinen et al., 2000). The advantages of this method are as follows  

Selective hydrogen bonding between one of the blocks (P4VP) of BCs and the additive 

The supramolecular self-assembly between PS-Zi-poly(acrylic acid) (PAA) and imidazole-terminated hydrogen-bonding mesogenic groups was also used to prepare non-azo LCBCs (Chao et al., 2004). Owing to the attached LC properties, the nanostructures in the LCBC films obtained can be oriented by using an alternating current (AC) electric field, in a direction parallel to the electrodes. 

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The main supramolecular self-assembled species involved in analytical chemistry are micelles (direct and reversed), microemulsions (oil/water and water/oil), liposomes, and vesicles, Langmuir-Blodgett films composed of diphilic surfactant molecules or ions. They can form in aqueous, nonaqueous liquid media and on the surface. The other species involved in supramolecular analytical chemistry are molecules-receptors such as calixarenes, cyclodextrins, cyclophanes, cyclopeptides, crown ethers etc. Furthermore, new supramolecular host-guest systems arise due to analytical reaction or process. 

A review13 with 53 references of the transition-metal mediated supramolecular self-assembly is presented. Focus is on the self-assembly of macrocycles, catenanes, and cages from (en)Pd(N03)2 and pyridine-based bridging ligands. 

Thus, the concept and manifestation of molecular recognition mediated supramolecular self-assembly of small chemical units, be it an ABn type building block or a dendrimer molecule, have proved to be vital factors in bridging the gap between small molecules and novel new-age materials. 

In organogermanium dithiophosphinates the ligand is monodentate, whereas in heavier metal compounds M -S secondary bonds may result in supramolecular self-assembly. Examples are monomeric Ph3GeS(S)PR2 (R = Me, Ph),165 and Me2Sn(S2PR2)2 (R = Me,166 Et167), supramolecular chain-like... 

The great structural diversity of coordination patterns and supramolecular self-assembly has been analyzed in detail for nickel(II), zinc(II), mercury(II), and tellurium (II),246fe(xanthato) complexes. 

The structural chemistry of some metal dithiocarbamates, i.e. systematics, coordination modes, crystal packing, and supramolecular self-assembly patterns of nickel, zinc, cadmium, mercury,363 organotin,364 and tellurium,365 366 complexes has been thoroughly analyzed and discussed in detail. Supramolecular self-assembly frequently occurs in non-transition heavier soft metal dithiocarbamates. Thus, lead(II),367 bismuth(III)368 zinc,369 cadmium,370 and (organo)mercury371 dithiocarbamates are associated through M- S secondary bonds, to form either dimeric supermolecules or chain-like supramolecular arrays. The arsenic(III)372 and antimony(III)373 dithiocarbamates are... 

Arsenic dithiocarbamates, As(S2CNR2)3 (R = Bu, CH2Ph),399 and toluene-3,4-dithiolato arsenic and bismuth dithiocarbamato derivatives, (MeC6H3S2) M(S2CNR2) (M = As, Bi R = Me, Et, CH2CH2)400 have been structurally characterized and the supramolecular self-assembly in Sb(III) dithiocarbamates has been carefully examined.401... 

The number of building blocks for supramolecular self-assembly is virtually unlimited. Chapter 6, by Brunsveld, Rowan, Nolte, and Meijer, describes studies on disk-shaped molecules which are programmed to stack in a helical fashion, leading to novel kinds of twisted fibers as well as lyotropic and thermotropic liquid crystalline materials. 

Impressive, highly ordered centimetre-sized fibres are obtained whose synergistic growth mechanism based on the kinetic cross-coupling of a dynamical supramolecular self-assembly and a stabilizing silica mineralization may well be the basis of the synthetic paths used by Nature to obtain its materials with well-defined multiscale architectures in biological systems. 

Georgakilas V, Pellarini F, Prato M, Guldi DM, Melle-Franco M, Zerbetto F (2002). Supramolecular self-assembled fullerene nanostructures. Proc. Natl. Acad. Sci. USA. 99 5075-5080. 

Richard C, Balavoine F, Schultz P, Ebbesen TW, Mioskowski C (2003) Supramolecular self-assembly of lipid derivatives on carbon nanotubes. Science 300 775-778. 

Besides reactions with alkali salts, there are several groups investigating metal-ligand bond formation by mechanochemical methods. For example Orita et al. have shown that the supramolecular self-assembly of a number of complexes can take place under solvent-free conditions, leading to higher-order fabrications of two- or three-dimensional topology and even double... 

Recently, a new class of supramolecular CpRu-containing catalysts for hydration of alkynes has emerged. These catalysts are based on the supramolecular self-assembly of monodentate ligands through hydrogen bonding association, as shown in Scheme 10.9 [41-43]. The remarkable activity of catalytic systems such as 15-17... 

Yan D, Zhou Y, Hou J. Supramolecular self-assembly of macroscopic tubes. Science 2004 303 65-67. 

Ghosh S, Rasmusson J, Inganas O. Supramolecular self-assembly for enhanced conductivity in conjugated polymer blends. Ionic crosslinking in blends of poly(3,4-ethylenedioxythio-phene)-poly(styrene sulfonate) and poly(vinylpyrrohdone). Adv Mater 1998 10 1097-1099. 

Establishing and understanding the impact of F-chains on the formation, structure, dynamics, and properties of molecules and supramolecular self-assemblies comprising fluorinated components is another permanent goal. Such knowledge will help predict and control the formation and properties of F-compounds and assemblies. 

We saw in Figure 1.2c that supramolecular chemistry is not just about solid state or solution host-guest chemistry but increasingly emphasises self-assembly and the construction of multi-nanometre scale devices and ultimately materials based on nanometre-scale components (a nanometre is 10 9 of a metre). Strict supramolecular self-assembly (Chapter 10) involves the spontaneous formation of a multi-component aggregate under thermodynamically controlled conditions based on information encoded within the individual building blocks (referred to as tectons ) themselves. The aggregate might comprise only one kind of molecule (as in the multiple copies of the same protein that comprise... 

The self-assembling double-helical structure of DNA has provided the inspiration for a further area of supramolecular self-assembly, namely the use of metal ions to template the assembly of organic threads into... 

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