Supramolecular structures assembly

Wu B, Liang JJ, Yang J et al (2008) Sulfate ion encapsulation in caged supramolecular structures assembled by second-sphere coordination. Chem Commun 1762-1764... 

The term synthon is more familiar to organic chemists and describes fragments from which varions molecnles can be bnilt by synthetic procedures. Sometimes the term was also used to describe structural units within supermolecules which can be formed and/or assembled by known or conceivable synthetic operations involving intermolecular interactions To avoid confusion, the term tecton was introduced to describe the molecular units of supramolecular structures assembled through noncovalent forces. Thus, the tecton has been defined as any molecule whose interactions are dominated by particular associative forces that induce self-assembly of an organized network Here, we will use the term synthon for... 

A strategy to manipulate supramolecular structures assembled from rod segments may be accessible by the alteration of the coil architecture (linear (5) versus branched (6)) in the rod-coil system [36]. On the basis of SAXS and TEM results, rod-coil molecules (5) with a linear PPO coil showed a honeycomb-like lamellar rod assembly with hexagonally arrayed PPO coil perforations, while the rod-coil molecules (6) with a dibranched PPO coil self-organized into rod-bundles with a body-centered tetragonal symmetry surrounded by a PPO coil matrix (Fig. 3). The notable feature is that a sim-... 

In living organisms the molecules in supramolecular structures assemble spontaneously. Biomolecules are able to self-assemble because of the steric information they contain. 

Some related examples with BR2 monocapped ligands are also known [181] and one of these molecules, 129, assembles to an interesting supramolecular structure, in which the cobalt(III) ions in a methylcobaloxime unit are coordinated to the pyridine residues of the bridging B(py)(OMe) group (Fig. 34). The dinuclear complex forms a large rectangular cage that is limited by the two pyridine residues and the cobaloxime moieties. The two pyridine... 

Fig. 34. Compound 129 assembles to a supramolecular structure through coordinative bonds between the cobalt(III) ions and the pyridine residues of the bridging B(py)(OMe) group...

Given the actual scenario, one can state that the emerging field of nanotechnology represents new effort to exploit new materials as well as new technologies in the development of efficient and low-cost solar cells. In fact, the technological capabilities to manipulate matter under controlled conditions in order to assemble complex supramolecular structures within the range of 100 nm could lead to innovative devices (nano-devices) based on unconventional photovoltaic materials, namely, conducting polymers, fuUerenes, biopolymers (photosensitive proteins), and related composites. 

Due to its unique chemical composition and structure, DNA can interact with a plethora of chemical structures via numerous types of bonds. This property ultimately defines the ability of DNA fragments to serve as the building blocks in the complex three-dimensional self-assembled structures. Following we Ust four major types of polymer/DNA interactions that can lead to formation of supramolecular structures ... 

Other supramolecular structures such as catenanes and rotaxanes can be formed using zinc as a template ion for example, a benzylic imine catenate formed by Leigh et a/.288 The reversible five-component assembly of a [2]catenane from a chiral metallomacrocycle and a dinaphtho-crown ether has been achieved. Zinc is used as the metal component and drives assembly via the coordination to a bipyridyl unit 7r interactions between the aromatic components are also... 

Other supramolecular structures such as dendrimers have also been synthesized with zinc-containing porphyrins. Sixteen free base and sixteen zinc porphyrin units were added at the fifth generation of dendritic poly(L-lysine) and intramolecular fluorescence energy transfer was observed.823 Assembly of supramolecular arrays in the solid state has been achieved with the incorporation of an amide group for hydrogen bonding. Zinc meso-tetra(4-amidophenyl)porphyrin... 

Bikadi Z, Zsila F, Deli J, Mady G, and Simonyi M. 2002. The supramolecular structure of self-assembly formed by capsanthin derivatives. Enantiomer 7 67-76. 

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,... 

In recent years, with increasing recognition of the roles played by specific noncovalent interactions in biological systems and chemical processes, the science of noncovalent assemblies- often called supramolecular science- has aroused considerable interest [76], The remaining part of this article reviews some important studies made on rotaxane and catenane, two classic types of supramolecular structure. 

Liquid Crystalline Functional Assemblies and Their Supramolecular Structures... 

PXX groups in complexes 87-90 can also slipped-stack to form columns located between the Pc columns and sheets. Since the crystal structures and supramolecular assembles of this type of phthalocyanine were well summarized in 2001 [12] and 2005 [79], we will present briefly only one typical Pc %-% supramolecular structure that has not been included in the previous section. As shown in Fig. 23, the Pc units in 89 form a 2D sheet along the ac plane. The overlap mode is type G Pc %-% interactions along both the a- and c-axes. This sheet further interacts with another sheet by type C overlap, forming a double sheet. 

Molecular calculations provide approaches to supramolecular structure and to the dynamics of self-assembly by extending atomic-molecular physics. Alternatively, the tools of finite element analysis can be used to approach the simulation of self-assembled film properties. The voxel4 size in finite element analysis needs be small compared to significant variation in structure-property relationships for self-assembled structures, this implies use of voxels of nanometer dimensions. However, the continuum constitutive relationships utilized for macroscopic-system calculations will be difficult to extend at this scale because nanostructure properties are expected to differ from microstructural properties. In addition, in structures with a high density of boundaries (such as thin multilayer films), poorly understood boundary conditions may contribute to inaccuracies. 

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. 

Some antimony and bismuth xanthates tend to self-assemble through M - -S secondary bonds into supramolecular structures. 

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... 

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