Host-guest properties functionalized

Baars et al. recently investigated the host-guest properties of polypropylene imine) dendrimers functionalized with tris-3,4,5-tri(tetraethyleneoxy)benzoyl units (Figure 16.15) [191]. These hosts are highly soluble in a broad range of solvents, from apolar solvents such as toluene to polar aqueous media. 

Wheel-and-axle organic diols are host systems well known in the solid state. The introduction of a metal into the wheel-and-axle molecular frame opens the way for the design of materials with multiple functions, joining chemical and structural properties of the metal centre with the steric and supramolecular attitudes of the organic matrix. This chapter treats the rationalization of host-guest properties of wheel-and-axle inorganic diols. 

Host-Guest Properties of Mono-functionalized Pillar[5]arenes... 

As with pillar[5]arenes, modification of 12 functional substituents on pil-lar[6]arenes is a useful way to improve their host-guest property. Huang and co-workers synthesized a pillar[5]arene with 12 mono(ethylene oxide) substituents (H5.39 Figure 5.33). °... 

Owing to the unique host-guest properties of calixarene macrocycles, calixarene-functionalized silica particles were used as cation-selective receptor colloids [81], and separator of lanthanides and actinides [82]. Calixarenes were also used for the syntheses of Ru, Pt and Pd NPs [83-85]. Furthermore, photoluminescence and charge-transfer complexes of calixarenes and calix[4]arene-based glycoclusters were grafted onto the surface of Ti02 NPs [64, 86]. 

Baars MWPL, Meijer EW (2000) Host-Guest Chemistry of Dendritic Molecules. 210 131-182 Balczewski P, see Mikoloajczyk M (2003) 223 161-214 Ballauff M (2001) Structure of Dendrimers in Dilute Solution. 212 177-194 Baltzer L (1999) Functionalization and Properties of Designed Folded Polypeptides. 202 39-76 Balzani V, Ceroni P, Maestri M, Saudan C, Vicinelli V (2003) Luminescent Dendrimers. Recent Advances. 228 159-191 Barre L, see Lasne M-C (2002) 222 201-258 Bartlett RJ, see Sun J-Q (1999) 203 121-145... 

The H-bonding in the anhydrous 1 Im (Table 24) has topologic properties (Fig. 46) similar to those in the alcohol coordinatoclathrates of 1 with 1 2 host guest stoichiometry (cf. Fig. 17 a). Assuming a perfectly ordered crystal lattice, the resulting central loop of H-bonds should appear to have homodromic directionality with the donor/acceptor functions separated in space. This contrasts to the behavior in the dihydrated l Im where no such characteristic loops are formed. Involvement of the C—H hydrogen atoms of the imidazole molecule, however, is similar in both cases. 

The building blocks of supramolecular systems are held together by intramolecular interactions and these systems are reversible. This intrinsic property is not only a consequence of the more labile interactions within supermolecules, compared to covalent bonds in molecules, but reversibility is essential for the function expressed by supramolecular systems. Kinetics can never be inferred from thermodynamic studies. For example, the knowledge of a host-guest equilibrium constant does not... 

As a start to a tetralogy on dendrimers, the volumes Dendrimers and Den-drimers II have already appeared in print. This mini-series continues now with the latest volume Dendrimers III and will be completed by the fourth volume Dendrimers IV within the next few months. Volume III offers dendrimers based on novel design concepts leading to highly stiffened and shape persistent dendritic structures as well as to new families of rather soft and floppy dendrimers and focuses on new functional properties and materials aspects. As an example, the question of host-guest interactions with dendrimers, whose existence has been under intense debate for a long time, finds its final - and positive - answer in this volume. As a consequence, dendrimers clearly represent a subset of supramolecular chemistry. 

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