Supramolecular assembly, definition

For many chemists LCs are mysterious and complex materials, their very definition defying a simple understanding. The basic idea behind this discussion of stereochemistry in LCs is that molecules and LCs represent the same phenomenon. Liquid crystals are supermolecules in a different way than are supramolecular assemblies. Indeed, LCs can be composed of supramolecular... 

Computational modeling can be a very powerful tool to understand the structure and dynamics of complex supramolecular assemblies in biological systems. We need to sharpen the definition of the term model somewhat, designating a procedure that allows us to quantitatively predict the physical properties of the system. In that sense, the simple geometrical illustrations in Fig. 1 only qualify if by some means experimentally accessible parameters can be calculated. As an example, a quantitative treatment of DNA bending in the solenoid model would only be possible if beyond the mechanical and charge properties of... 

Interaction energies are thus well-defined, but more than one definition is possible as we shall see in the following. For modeling the interactions of molecules in a supramolecular assembly one may define a chemical reaction like... 

Supramolecular assemblies are, by definition, complex affairs and often generate spectral data that are hard to interpret. If the system can resolve into regular single crystals then the possibility of determining the solid-state structure evolves. From experience, supramolecular systems tend to fall into one of two classes in the crystalline state. They may produce wonderfully rigid one-, two- or three-dimensional... 

It is the merit of the present book to treat chirality in a unified manner and to contribute in this way to bridging the gap between organic and coordination chemistry. One hundred years after Alfred Werner s fundamental work, Chirality in Transition Metal Chemistry Molecules, Supramolecular Assemblies and Material is the definitive text about this important subject and it will serve as an introduction for students and as a reference for researchers for a long time to come. 

Nanocasting Strategies and Porous Materials, p. 950 Self-Assembly Definition and Kinetic and Thermodynamic Considerations, p. 1248 Supramolecular Polymers, p. 1443 Suifactants, Parti Fundamentals, p. 1458 Sulfactants, Part II Applications, p. 1470... 

Micelles and Vesicles, p. 861 Self-Assembly in Biochemistry, p. 1257 Supramolecular Chemistry Definition, p. 1401... 

Hemoglobins O2 Uptake and Transport, p. 636 Molecular Logic Gates, p. 893 Molecular-Level Machines, p. 931 Phthalocyanines, p. 1069 71—71 Stacking Theory and Scope, p. 1076 Potphyrin-Based Clathrates, p. 1150 Self-Assembly Definition and Kinetic and Thermodynamic Considerations, p. 1248 Self-Assembly Terminology, p. 1263 Strict Self-Assembly and Self-Assembly with Covalent Modifications, p. 1372 Supramolecular Photochemistry, p. 1434 Vitamin 8/2 and Heme Models, p. 1569... 

Anion-Directed Assembly, p. 51 Enzymes Characteristics and Mechanisms, p. 554 Hydrogen Bonding, p. 658 Molecular Squares, Boxes, and Cubes, p. 909 Molecular-Level Machines, p. 931 Protein Supramolecular Chemistry, p. 1161 Racks, Ladders, and Grids, p. 1186 Self-Assembling Catenanes, p. 1240 Self-Assembly Definition and Kinetic and TTjermot/ynam-ic Considerations, p. 1248 Self-Assembly in Biochemistiy, p. 1257 The Template Effect, p. 1493... 

In this triad only mercury seems to form definite supramolecular assemblies by secondary bonding interactions. The supramolecular chemistry of zinc and cadmium (based upon dative bond self-assembly) has been discussed in Sections 3.1.1 and 3.1.2. 

With regard to its electronic properties, no studies are available that clearly demonstrate that electron transfer through such a supramolecular assembly is possible. Solid-state electrochemical studies on the crystalline material are not available at the present time. The closest to supramolecular electrochemistry are studies of ordered two-dimensional peptide arrays on gold. For some Fc-peptide cystamines, self-assembled monolayers of Fc-peptide cystamines were prepared that allow the quantification of the electron transfer kinetics by electrochemical techniques. Similar to the supramolecular assemblies, H-bonding plays an important role. At the present time (2003), only a few systems were studied and offer a rather complex picture of the ET properties. Additional experimental work is required to obtain definite results on the influence of the peptide primary and secondary structure on ET kinetics. In addition, tile issue of lateral interactions needs to be addressed by detailed dilution studies with alkylthiols. 

Intermolecular recognition and self-assembly processes both in the solid, liquid, and gas phases are the result of the balanced action of steric and electronic factors related to shape complementarity, size compatibility, and specific anisotropic interactions. Rather than pursuing specific and definitive rules for recognition and self-assembly processes, we will afford some heuristic principles that can be used as guidelines in XB-based supramolecular chemistry. 

Paraphrasing Corey s historic definition of synthon [203], Desiraju defined a supramolecular synthon as a structural unit within a supermolecule that can be formed or assembled by known or conceivable synthetic operations involving intermolecular interactions [204], The robustness of the XB has allowed several supramolecular synthons based on this interaction to be identified and some examples have been presented in this chapter. 

Supramolecular chemistry has been defined by one of its leading proponents, Jean-Marie Lehn, who won the Nobel Prize for his work in the area in 1987, as the chemistry of molecular assemblies and of the intermolecular bond . More colloquially this may be expressed as chemistry beyond the molecule . Other definitions include phrases such as the chemistry of the non-covalent bond and non-molecular chemistry . Originally supramolecular chemistry was defined in terms of the non-covalent interaction between a host and a guest molecule as highlighted in Figure 1.1, which illustrates the relationship between molecular and supramolecular chemistry in terms of both structures and function. 

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