Metallo-supramolecular complexe

REACTIVITY OF SUPERMOLECULES IN SOLUTION METALLO-SUPRAMOLECULAR COMPLEXES... 

A number of other systems have been shown to be suitable for multilayer build-up by the ESA, like charged latex nanospheres [50,199,285-287] or metallo-supramolecular complexes [288-290]. ESA has also been combined with Langmuir-Blodgett transfer [291-294], and even superlattice films have been produced. 

Schubert US, Eschbaumer C Angew Chem Int Ed (2002) 41 2892-2926 Macromolecules containing bipyridine and terpyridine metal complexes towards metallo-supramolecular polymers... 

Bis(P-diketones) ligands, were proved to be efficient motifs or structural elements for selfassembling highly luminescent metallo-supramolecular lanthanide complexes [53-59] and representative examples (H2L" ) are shown in Figure 2.8. Special attention has also been paid to the use of enantiomerically pure bis-P-diketones ofH2L " [58]. H2L ° in Figure 2.8 was shown to have the ability to form d-f-d molecular magnetic materials [60]. 

If 4,4 -bipyridine is mixed with (dppp)Pd(II) or (dppp)Pt(II) triflates (dppp = bis-(diphenylphosphine) propane), the two reactants spontaneously self-assembly [53] to the metallo-supramolecular square shown in Fig. 5.24, because the weakly coordinating counterions leave two coordination sites open at the metal complex. By virtue of the dppp ligand, the coordination angle of 90° is fixed. It is rather difficult to ionize these squares as intact but completely desolvated entities, but under the... 

Symmetry driven self-assembly of metallo-supramolecular architectures in metal complexes with 2,2 -bipyridine and 8-hydroxyquinoline ligands 07BCJ797. 

In all of the studies summarized above, the Mebip ligands were covalently attached to a telechelic core and served either to chain-extend or cross-link these building blocks, in connection with various metal ions, into linear or cross-linked metallo-supramolecular polymers. Rowan et al. took a different approach when they blended complexes based on monofunctional dodecyl-Mebip and metal ions into methacrylate-based polymer matrices [85]. Interestingly, when complexes with platinum ions were used, a mechanically responsive material was obtained, which... 

Fig. 29 Schematic illustration of the self-assembly of amphiphilic metallo-supramolecular block copolymers under encapsulation of cargo into micelles and disassembly of the micelles under release of the drug upon ultrasound sonication via dissociation of the metal-ligand complex. Upon cessation of the ultrasonication, the micelles re-assemble again [96]...

In the following sections metal-ligand assemblies are organized in terms of metal coordination number and geometry. Within each subsection structures are discussed in the order of increasing nuclearity and complexity. Discussion of metallo-supramolecular assembly properties and development of function follows the review of synthesis and structure. 

Fig. 7 Metallo-supramolecular polymer gels as introduced by Rowan and coworkers, (a) Organogels formed by complexation of lanthanide and transition metal ions to 2,6-bis (l-methylbenzimidazolyl)pyridine (BIP)-functionalized poly (ethylene glycol), (b) Thermo- and mechanoresponsiveness of these gels. Reprinted with permission from [134]. Copyright 2003 American Chemical Society...

Fig. 14 Access to shape-memory materials from photocross-linked metallo-supramolecular polymers. (a) Formation of shape-memory materials using light as a stimulus (a) UV light is absorbed by the metal-ligand complexes and is converted to localized heat, which disrupts the metal complexation (i>) the material can then be deformed (c) removal of the light while the material is deformed allows the metal-ligand complexes to re-form and to lock-in the temporary shape id) additional exposure to UV light allows a return to the permanent shape, (b) Images demonstrating the shape-memory behavior. Reprinted with permission from [274]. Copyright 2011 American Chemical Society...

Finally, porphyrins and metalloporphyrins have been the focus of countless studies in supramolecular photochemistry over the past several decades. In keeping with the importance of this area to the field of supramolecular photochemistry. Chapter 6 is dedicated to the properties of supramolecular porphyrin and metallo-porphyrin complexes. Takagi and Inoue have put together an excellent chapter that exhaustively explores the fundamental properties of metalloporphyrins. In addition, they describe the supramolecular porphyrin complexes that are constructed from porphyrin units by using covalent and noncovalent approaches. 

Figure 7 Crystal structures of prismatic metallo-supramolecular assemblies, (a) Tetrahedral [Ag4(33)4]" + with included CH3CN shown in space-filling mode (b) the topologically complicated complex [Pd4(34)4(N03)2(H20)2] + (c) tetrahedral [(VO)6(CTC-6H)4(Mg(H20)4)3] anion with chelating deprotonated CTC ligands Mg centers shown in green, V in purple and (d) the stella octangula structure of [Pdg(35)8] + shown in space-filling mode with each ligand in a different color.

Bis(/3-diketones) ligands were proved to be efficient motifs or structural elements for self-assembling highly luminescent metallo-supramolecular lanthanide complexes, and representative ones are shown in Fignre 7. 

Figure 4.11 Metallo-supramolecular polymers based on (a) SCS-Pd" prncer-pyridine or SCS-Pd" pincer-nitrile complexes and (b) Ru(bpy)3 + side chains.

Helicates are defined as metallo-supramolecular coordination compounds in which linear ligands wrap around several metal ions in a helical fashion. The helicate term was introduced by J. M. Lehn in 1987, and from that point the chemistry of helicates became a prominent subdiscipline of supramolec-ular chemistry. Initially, helicates were considered simple model compounds explaining mechanistic aspects of self-assembly. Recently, special properties of the oligonuclear complexes became more important for developing novel materials based on the helicate motif. ... 

This book fills an important gap, since for the first time it is entirely devoted to condensation TPEs. The following considerations place landmarks of the new chemistry in this field, rather than browsing the recent improvements of the well established TPEs. Several new techniques appeared quite recently they are already patented, if not applied, and are very promising. This is the case of the metallo-supramolecular block copolymers [189], which result from the chelation of complexing group end-capped oligomers with different metal derivatives and the homopolymers and copolymers prepared from metal-containing macrocycles [190,191]. 

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