Supramolecular compounds definition

So far we have focused on Lehn s definition of a supramolecular compound as one involving non covalent interactions (Section 1.1). Such a definition is entirely appropriate to host-guest chemistry,... 

Classification and Nomenclature of Supramolecular Compounds, p. 267 Clathrate Hydrates, p. 274 Crystal Growth Mechanisms, p. 364 Self-Assembly Definition and Kinetic and Thermodynamic Considerations, p. 1248 Self-Assembly in Biochemistry , p. 1257 Supramolecular Polymers, p. 1443... 

These descriptions, while helpful, are by their nature noncomprehensive and there are many exceptions if such definitions are taken too literally. The problem may be linked to the definition of organometallic chemistry as the chemistry of compounds with metal-to-carbon bonds . This immediately rules out Wilkinson s compound, RhCl(PPh3)3, for example, which is one of the most important industrial catalysts for organometallic transformations known in the field. Indeed, it is often the objectives and thought processes of the chemist undertaking the work, as much as the work itself, which determine its field. Work in modern supramolecular chemistry encompasses not just host-guest systems but also molecular devices and machines, molecular recognition, so called self-processes ... 

A large number of covalently linked systems are currently being synthesized and investigated, differing in the nature of A, B, and L, as well as in the number of functional units in the supramolecular system (nuclearity). It is common to call simple two-component donor-acceptor systems such as that of Eq. 2 dyads , and progressively more complex systems triads , tetrads , pentads , etc.. Systems where all the A and B units are organic molecules are dealt with in Chapter 1 of this section. The present chapter deals with systems where at least one of the A/B functional units is a transition metal coordination compound. From this definition, however, are excluded (a) systems where A and/or B are porphyrins or related species (dealt with in Chapter 2) and (b) systems of high nuclearity with dendritic structures (dealt with in Chapter 9). 

There are many metal complexes, metallomesogens, which deomonstrate liquid crystal or mesomorphic properties, and the organization of metal complexes in fluid phases is definitely supramolecular behaviour. These compounds were well reviewed in 1991 [20a], 1992 [20b] and 1993 [20c] the strength of this research in Europe and Japan is evident. 

Fig. 1 Definitions and overall scheme of supramolecular events (a) chemical host synthesis and formation of a supramolecule (host-guest inclusion compound) (b) endo- and exosupramolecular receptor-substrate (host-guest) chemistry and (c) formation of mono-and multimolecular inclusion compounds.

This short review deals with supramolecular intercalates. Supramolecular intercalates is a term open to considerable breadth of definition. Within the scope of this article, the author chose to focus on two-dimensional solids, based upon weak interactions, that demonstrate intercalation ability. An emphasis is placed on frameworks that demonstrate flexibility of structure and the benefits of such compounds. This short review is not meant to be comprehensive, as many systems that may fall under the broad umbrella of "supramolecular intercalates" were reviewed elsewhere. " This review is meant simply as an overview of some examples in this topical field that readily illustrate the potential of soft networks. 

Isostructurality of Inclusion Compounds, p. 767 Neutron Diffraction, p. 959 71-71 Interactions Theory and Scope, p. 1076 Polymorphism, p. 1129 Supramolecular Isomerism, p. 1420 Tectons Definition and Scope, p. 1484... 

---