Silver supramolecular complexes

Figure 8 Ligands which form silver(I) complexes with supramolecular structures through 71-71 interactions.

The silver(I) complexes with the tetrakis(methylthio)tetrathiafulvalene ligand have been reported, the nitrate salt presents a 3D structure with an unprecedented 4.16-net porous inorganic layer of silver nitrate,1160 the triflate salt presents a two interwoven polymeric chain structure.1161 The latter behaves as a semiconductor when doped with iodine. With a similar ligand, 2,5-bis-(5,5,-bis(methylthio)-l,3,-dithiol-2 -ylidene)-l,3,4,6-tetrathiapentalene, a 3D supramolecular network is constructed via coordination bonds and S"-S contacts. The iodine-doped compound is highly conductive.1162 (Methylthio)methyl-substituted calix[4]arenes have been used as silver-selective chemically modified field effect transistors and as potential extractants for Ag1.1163,1164... 

Two halide-centered cubane silver cluster complexes, containing discrete units, [Ag8X Se2P(OEt)2 6][PF6], or unidimensional chains, Ag8X[Se2-P(OEt)2]6X ra (X = Br and Cl) have been reported. This is an interesting case where the counter ions dictate the molecular/supramolecular architecture.440... 

The complexation of anionic species by tetra-bridged phosphorylated cavitands concerns mainly the work of Puddephatt et al. who described the selective complexation of halides by the tetra-copper and tetra-silver complexes of 2 (see Scheme 17). The complexes are size selective hosts for halide anions and it was demonstrated that in the copper complex, iodide is preferred over chloride. Iodide is large enough to bridge the four copper atoms but chloride is too small and can coordinate only to three of them to form the [2-Cu4(yU-Cl)4(yU3-Cl)] complex so that in a mixed iodide-chloride complex, iodide is preferentially encapsulated inside the cavity. In the [2-Ag4(//-Cl)4(yU4-Cl)] silver complex, the larger size of the Ag(I) atom allowed the inner chloride atom to bind with the four silver atoms. The X-ray crystal structure of the complexes revealed that one Y halide ion is encapsulated in the center of the cavity and bound to 3 copper atoms in [2-Cu4(//-Cl)4(//3-Cl)] (Y=C1) [45] or to 4 copper atoms in [2-Cu4(/U-Cl)4(/U4-I)] (Y=I) and to 4 silver atoms in [2-Ag4(/i-Cl)4(/i4-Cl)] [47]. NMR studies in solution of the inclusion process showed that multiple coordination types take place in the supramolecular complexes. 

Selenotrithionates, 2 256 Selenous acid, secondary bonding by, 15 19 Self-assembling metal complexes, 46 174-175, xee also Supramolecular copper (l)/silver (I) complexes... 

Solid-state supramolecular complexes, see Su-pramolecular copper(l)/silver(I) complexes Solubility products, 17 215 Soluble methane monooxygenase protein system, 42 263-286 hydroxylation... 

The first descriptions of heteronuclear luminescent supramolecular complexes were given by Fackler et al. in 1988 and 1989. In these studies, one gold-thallium and one gold-lead complex were reported. As in the case of the gold-silver dinuclear systems, the extended systems appeared as a result of the unidirectional polymerization of dinuclear or trinuclear units through metal-metal interactions. These were prepared by reaction of the gold precursor [PPN][Au(MTP)2] (PPN = N(PPh3)2 ... 

Figure 8.10 Soluble supramolecular complexes of carbon nanotubes, 0.01 M Na2S04, aqueous solution. Scan rate = 0.1 V/s T— 25°C working electrode is Pt disc (r — 0.05 cm). Potentials measured versus silver quasi-reference electrode (approximately —0.05 V versus SCE). Ref. 121, Reproduced by permission of the Royal Society of Chemistry.

Several silver(I) complexes with crown ethers and calixarenes have been synthesized. In the design of discrete molecules and infinite chains in silver acetylide chemistry, crown ethers function as blocking groups or protective cordons around a polyhedral C2 Ag cage so that the isolation of lower-dimensional supramolecular entities can be achieved. " ... 

Studies of a supramolecular complex of silver(I) and a cholaphane. Virtanen and co-workers reported the results of a study involving a supramolecular complex of a cholaphane analogue (244) with Ag(I) The authors used a 50 ms optimized HMBC spectrum to assign the piperazine nitrogen shifts with and without Ag(I). 

As an example, it was reported that the TfO salt of the tetracoordinated silver(l) complex with 2,2 -bipyridine-4,4 -disubstituted ligands 33 yielded a novel ionic liquid crystal displaying columnar mesomorphism [69]. The coordination and the ionic bonds drive the supramolecular assembly because the ligand is nonmesogenic or smectic, but when coordinated to the metal, it gives columnar mesomorphism... 

Khlobystov, A.N. Blake, A.N. Champness. N.R. Leme-novskii. D.A. Majouga. A.G. Zyk, N.V. Schroder, M. Supramolecular design of one-dimensional coordination polymers based on silver(I) complexes of aromatic nitrogen-donor ligands. Coord. Chem. Rev. 2001. 222. 155-192. 

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