Supramolecular Materials Engineering

In this contribution we have also underlined an emerging aspect of solid-state chemistry, namely that solvent-free solid-state synthetic procedures can be exploited to construct bottom-up new materials from molecular or ionic building blocks. This is at the core of molecular crystal engineering [81]. It is fascinating to think that the crystal engineer may free him/herself from operating with solvent to achieve the bottom-up construction of supramolecular materials completely from sohd to sohd . 

The directed manipulation of intermolecular interactions (hydrogen bonding, van der Waals forces, metal coordination) gives access to a supramolecular engineering of molecular assemblies and of polymers (see, for instance, [7.10-7.13, 7.44, 9.142, 9.157, 9.161-9.163]) through the design of instructed monomeric and polymeric species. It leads to the development of a supramolecular materials chemistry (see Section 9.8). 

Via recognition-directed association and self-organization processes, supramolecular chemistry has opened new perspectives in materials science towards the design and engineering of supramolecular materials. These, again, are dynamic by nature, whereas molecular materials must be rendered dynamic by introduction of reversible covalent connections between building blocks. Because of their intrinsic ability to exchange their components, they may in principle select them in response to external stimuli or environmental factors and therefore behave as adaptive materials of either molecular or supramolecular nature [7-9]. 

This chapter does not cover the use of metal ions as allosteric effectors (3), skeletal components (4) (see Crystal Engineering, Supramolecular Materials Chemistry), or sensing elements (5) (see Molecular Redox Sensors, Colorimetric Sensors and Luminescent Sensing, Supramolecular Devices). It also does not address the interaction of metal complexes with biological systems (see Synthetic Peptide-Based Receptors, Biological Small Molecules as Receptors, Molecular Recognition and Supramolecular Bioinorganic Chemistry, Supramolecular Aspects... 

Molecular information-based recognition events represent a means of performing programmed materials engineering and processing of biomimetic or abiotic type and may lead to self-assembling nanostructures, organized and functional species of nanometric dimensions that define a supramolecular nanochemistry, an area to which supramolecular polymer chemistry is particularly well suited and able to make important contributions. 

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