Molecular systems crystalline assemblies

Molecular dynamics (MD) is a method in which Newton s equations of motion are solved for a molecular system obeying a differentiable potential function. A few efforts at modeling proteins at interfaces using MD have appeared (183-187). Obviously, these studies provide dynamic as well as thermodynamic information on biomolecules at interfaces. Systems studied have included lysozyme and myoglobin on polyethylene glycol (183), cytochrome c on hydrophilic and hydrophobic self-assembled monolayers (184), leucine enkephalin near a crystalline polyethylene surface (185), thermal hysteresis proteins on ice (186), and lysozyme on polyvinylimidazole (187). 

The difference is considerable between ideal systems such as single crystals and semicrystalline polymers. Indeed, the presence of impurities (diluent), of stmctural defects, or even junctions and loops due to chain entanglement considerably lowers the regularity of crystalline assemblies. This results in a weakening of molecular... 

The use of ordered supramolecular assemblies, such as micelles, monolayers, vesicles, inverted micelles, and lyotropic liquid crystalline systems, allows for the controlled nucleation of inorganic materials on molecular templates with well-defined structure and surface chemistry. Poly(propyleneimine) dendrimers modified with long aliphatic chains are a new class of amphiphiles which display a variety of aggregation states due to their conformational flexibility [38]. In the presence of octadecylamine, poly(propyleneimine) dendrimers modified with long alkyl chains self-assemble to form remarkably rigid and well-defined aggregates. When the aggregate dispersion was injected into a supersaturated... 

Self-assembled monolayers (SAMs) provide a versatile system for control of the interfacial properties of inorganic compounds. SAMs result from the spontaneous adsorption and assembly of molecular compounds into crystalline structures. Commonly used molecules consist of a head group with a specific affinity for a particular material, and a terminal group containing a chemical function that becomes exposed... 

Supramolecular structures obtained via self-assembly processes may be named as another future topic, which just starts an increasingly rapid development.294 By some examples it was already demonstrated how molecular chirality may by translated into supramolecular chirality in such self-assembled structures and this may lead not only to new, improved host-guest systems but also eventually to new materials in a more general sense. Liquid-crystalline systems or materials for nonlinear optics may be mentioned just as two examples. 

In this chapter, we discuss several approaches that have led from molecular entities to supramolecular soft and hard molecular architectures. Systems based on metal complexes with d and d electronic configuration forming assemblies such as micelles, vesicles, and gels, as well as crystalline structures, will be illustrated. The focus is on the role played by the metal complexes chemical structures as well as the choice of the intermolecular interactions in the ground and/or excited electronic states within the arrays. The selected examples, based on noncovalently linked luminescent systems, aim to the development of multifunctional assemblies, in which the self-organization generates new... 

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