Supramolecular compounds complexes

In the organism tissues, fatty acids are continually renewed in order to provide not only for the energy requirements, but also for the synthesis of multicomponent lipids (triacylglycerides, phospholipids, etc.). In the organism cells, fatty acids are resynthetized from simpler compounds through the aid of a supramolecular multienzyme complex referred to as fatty acid synthetase. At the Lynen laboratory, this synthetase was first isolated from yeast and then from the liver of birds and mammals. Since in mammals palmitic acid in this process is a major product, this multienzyme complex is also called palmitate synthetase. 

In the field of porous supramolecular metal complexes, both molecular and extended-solid materials have been extensively studied in recent years. A particularly well-studied class of compounds is the metal-containing molecular squares, that is, square-shaped porous tetrameric structures (30,108). These have been prepared by several approaches, the most common being the reaction of an organic bridging ligand with a metal complex that has available cis-coordination sites (109-113) (Fig. 13). However, the resulting metal centers are usually coordinatively saturated, which makes it difficult for guest molecules to interact directly with the metal atoms. 

Combined thermoanalytical (TA,TGA and DSC) investigations of DBTA complexes of chiral alcohols may serve valuable data on the composition and stabilities of these solid supramolecular compounds. DSC monitoring of menthol resolution with DBTA in melt has already discussed in point 3.4. Thermal stability of further ten complexes of DBTA with alcohols 26, 29-31, 35-37 and 39-41 was also determined. [47] The melting points of the DBTA complexes (Table 11) increase in the 2-alkanol, 2-alkoxycyclohexanol, 2-halogenocyclohexanol order. 

Early work on the kinetics of photoinduced ET in transition metal complex systems focused exclusively on bimolecular reactions between transition metal chromophores and electron donors or acceptors. However, concomitant with the advances in rapid photochemical kinetic methods and chemical synthetic methodology, emphasis shifted to photoinduced ET in chromophore-quencher assemblies that comprise a metal complex chromophore covalently linked to an organic electron donor or acceptor [24]. These supramolecular compounds afford several... 

Single- and multiwalled carbon nanotubes represent attractive components for supramolecular structures. Their rod shape predestines them as guest molecules to be included inside host compounds that are designed like rings or hollow cylinders. From an arrangement with the host wrapped helically around the nano-tube, another type of supramolecular compound arises. The tubes can further serve as scaffold to supramolecular structures that form by a complexation of single tubes or bundles. Several examples of supramolecular patterns have already been discussed in Section 3.5.4.2 on the noncovalent functionalization of nano-tubes. Hence only some other specimens will be presented here. 

The interest in polynuclear supramolecular iron complexes mainly arises from the importance of oxo-centered polyiron aggregates as model compounds for iron-oxo proteins. In principle, / 3-oxo-centered complexes related to [Fe30(02CR)6(H20)3] [11] should also be accessible with doubly negatively charged bis-bidentate ligands. 

Supramolecular chemistry may be defined as "chemistry beyond the molecule." bearing on the organized entities of higher complexity that result from the association of two or more chemical species held together by intermo-lecular noncovalent forces, such as metal ion coordination, electrostatic forces, hydrogen bonding, van der Waals interactions, and others.These supramolecular entities derived from supramolecular association are generally called supermolecules or supramolecular compounds. Thus, one may say that "supramolecules are to... 

Due to their complex structure, systematic names of supramolecular compounds are cumbersome in use. This has given rise to many trivial names and descriptive... 

Classification and Nomenclature of Supramolecular Compounds, p. 261 Crown Ethers, p, 326 Cfyptands, p. 334 Hydrogen Bonding, p. 658 lonophores, p. 760 Kinetics of Complexation, p. 776 Lariat Ethers, p. 782... 

Usually the COOH functional groups act both as hydrogen-bond donors and acceptors. The dinuclear tungsten complex [(C5H4COOH)W(CO)3]2, 52 [118], is not a supramolecular compound but it is shown here as an example of hydrogenbonding between carboxylic acid functions and THE. 

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