Supramolecular assembly: bipyridyl

A bimetallic Os(II) complex of the macrocyclic ligand MAC1 (Scheme 2) was prepared and characterized by Venturi et al. Each Os(II) center of the complex has a [(bpy)20s(II)] fragment attached to one of the bipyridyl units of MAC1. The complex has absorption and luminescence behavior reasonably similar to that of [Os(bpy)3]2+ with an absorption maximum of 488 nm and emission with a maximum of 740 nm (trt = 59 ns, 0rt = 0.003). The complex may be used in the development of supramolecular assemblies [23]. 

An organic channel structure formed by the supramolecular assembly of trithiocyanuric acid and 4,4 -bipyridyl CO CD... 

Other supramolecular structures such as catenanes and rotaxanes can be formed using zinc as a template ion for example, a benzylic imine catenate formed by Leigh et a/.288 The reversible five-component assembly of a [2]catenane from a chiral metallomacrocycle and a dinaphtho-crown ether has been achieved. Zinc is used as the metal component and drives assembly via the coordination to a bipyridyl unit 7r interactions between the aromatic components are also... 

Scheme 21 Coupling of Peptide Segments to a Bipyridyl Ligand and Fe2+ Induced Self-Assembly of a Three-Helix Supramolecular Structure 56-57 ...

The stable organic solid containing channels formed by the supramolecular hydrogen-bonded assembly of trithiocyanuric acid and 4,4 -bipyridyl can accommodate aromatic molecules such as benzene, toluene and /7-xylene. The apo-host is thermally stable up to 200 °C and exhibits shape selectivity with respect to the xylene isomers. The channels do not accommodate mesitylene. It would be interesting to carry out chemical reactions in these channels. 

Diskin-Posner, Y. Patra. G.K. Goldberg. I. Crystal engineering of metalloporphyrin assemblies. New supramolecular architectures mediated by bipyridyl ligands. Chem. Commun. 2002. 1420-1421. 

For the most general approach to construct supramolecular dye assemblies through metal coordination, dye molecules must possess appropriate Lewis basic coordination sites, which are, however, usually scarce in parent dye molecules. Therefore, aromatic aza ligands, especially pyridyl, bipyridyl and terpyridyl groups, are often introduced into dye molecides by established organic synthetic routes to enable metal-aza Hgand interactions for the construction of dye assemblies of diverse structures and properties. Surprisingly, few classes of dyes have been subjected so far to produce supramolecular... 

Supramolecular systems assembled by peripheral and axial coordination were also thoroughly described. For example, heteroarrays held by axial coordination, particularly of zinc, nickel, ruthenium, tin, silicon, etc. porphyrins and phthalo-cyanines to peripheral pyridyl and 4,4-bipyridyl groups were described. Another interesting class of compounds are porphyrin dimers prepared by coordinative assembly of cw- icso-(4-pyridyl)porphyrins with PdCla forming two [PtCl2(pyP)2] complexes, and more complex tesselated structures by substitution of the platinum complex chloro ligands by 2,3-diamine(azaporphyrins), as depicted in Fig. 12. 

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