Complexes of Silver i

TT-Complexes of Silver(j). In the crystal structure of ex j-tricyclo[3,2,l,0 ]-oct-6-enesilver(i) nitrate the silver atom is symmetrically bonded to the olefinic double bond, the Ag-C distances being 2.41 and 2.42 A (98) the 

The crystal structure of the silver(i) salt of the antibiotic X-537A (105) contains dimeric units in which two silver ions are encapsulated by two organic anions. Each metal atom bonds to an aromatic multiple bond in 

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Marcos, M., Ros, M.B., Serrano, J.L., Sola, M.A., Oro, L.A. and Barbera, J. (1990) Liquid-crystal behavior in ionic complexes of silver(I) molecular structure-mesogenic activity relationship. Chemistry of Materials, 2, 748-758. 

Examples of silver(l) alkyl and alkenyl (including aryl) complexes have been known from as early as 1941 6-9 however, the number of examples is fairly limited with respect to that of the heavier congeners, copper(l) and gold(l). Such a phenomenon can readily be attributed to the relatively low stability of this class of complexes, both photochemically and thermally. Simple homoleptic alkyl and alkenyl complexes of silver(i) are known to be very unstable under ambient temperature and light, and successful isolation of this class is fairly limited and mainly confined to those involving perfluoroorganics.10 The structures and the metal-carbon bond-dissociation energies for... 

The complexes of silver(I) ions with substituted pyridines are well known and some representative thermodynamic data for their formation are included in Table 13.81-83 Several attempts have been made to correlate the stability of the silver complexes with the basicity of the substituted pyridines.81,82 In general, a linear relationship between the logarithm of the formation constants and the pKa of the free bases was found to exist. 

Silver(I) complexes of pyrazine were first reported in 1895." Since then there have been numerous reports on the preparation and properties of pyrazine complexes of silver(I).85 Thermodynamic data for some of these complexes are given in Table 18. 

Tellurocyanate complexes of silver(I) have not been reported. 

The formal reduction potential of silver ion in DMF was found to be +0.579 0.004 V vs. SCE. The values of the stability constants of the DMF complexes of silver(I) in various solvents are given in Table 38. It was observed that the complexes were most stable in nitroethane.274... 

Table 38 Stability Constants of DMF Complexes of Silver(I) in Various Solvents274...

Table 56 Formation Constants for some Complexes of Silver(I) Ions with Complexones...

Liquid-crystalline complexes of silver(I) were among the first complexes we studied and even now, some sixteen years later, we continue to find aspects that fascinate us. The silver complexes are different fi om the other complexes we have considered in that they are formally ionic, and the anion is an additional variable to take into accoimt. As will be seen, this proves to be a most subtle structural parameter. 

The tridentate BoxCarb ligand was used to synthesise the corresponding carbene complexes of silver(I), rhodium(III) and palladium(II) [101]. Interestingly, the potentially tridentate BoxCarb ligand coordinates in a bidentate fashion only in the case of the silver(l) complex and it is the linker-free oxazoline ring that remains pendant. The coordination... 

Having seen that structural predictions are very difficult, we will now turn to the choice of transition metal. We have already seen the dependence of the coordination mode in square planar complexes on various factors and noticed the preference for polymeric chains with the silver(I) complexes owing to the linearly coordinated silver centre. Chiu et al. [325] reported on a series of arylmethylene and methyl wingtipped bis-carbene complexes of silver(I) (polymeric bridging) and palladium(II) (monomeric chelating). Carbene transfer to palladium was achieved in DMSO since solubility in CHjCfj was very poor. 

The amide functionalised carbene complex of silver(I) proved to be less effective in the melt polymerisation of (L)-lactide than the nonfunctionalised carbene complex (carboxyhc acid amide group substituted by benzyl). The differences were only small and high conversion rates required high reaction temperatures. For lower temperatures (100-120°C) conversion rates were actually better for the functionalised carbene complex (but as low as 55-76%). 

The most important classes of oxygen donor ligands for complexation of silver(I) are /3-diketonates, carboxylates, crown ethers, and calixarenes. 

Canal JP, Ramnial T, Langlois LD et al. (2008) A three-step laboratory sequence to prepare a carbene complex of silver(I) chloride. J Chem Ed 85 416-419... 

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). 

B. Complexes of Silver(I) and Silver(III) with Perfluoroalkyl Ligands. .. 215... 

Four types of yhde complexes of silver(I) have been reported so far (a) mononuclear neutral [Ag(R)(ylide)], (b) mononuclear cationic [Ag(yhde)2]X, (c) dinuclear neutral [Ag2 (CH2)2ERR 2] (E = P, As) and (d) dinuclear dicationic [Ag2 CH(PPh3) 2CO 2]. 

Complexation of silver(I) triflate and tosylate salts to the related A, 7V -bis(hexadecanoyl)-l,10-diaza-4,7,13,16-tetrathiacyclooctadecane also formed smectic A phase, between 74 °C and 107 °C for the triflate compound, and between 125 °C and 173 °C for the tosylate. ... 

Sakano T, Okano M, Osakada K. Preparation of triazole-fumished ferrocene derivatives and their polymer complexes of silver(I). J Inorg Organomet Polym Mater 2009 19(1) 35 5. 

Complexes of silver(i) trifluoroacetate are included in a wide range of compounds LtAgX [L = (EtO)jP or (p-MeC,H4)jP] for which am.r. parameters, conductivities, and dissociation equilibria are reported. The gold carboxylatcs RpCOjAuCPPh,) (Rp = CFj or C F,) are prepared by reaction of the acid with Au(PPhj)Me, but an excess of the acid causes decompositioa Although the pentafluorobenzoate is readily decarboxy-lated at its melting point, the trifluoroacetate is completely decomposed. 

Complexes of Silver(i) and Gold(i).—Only three reports have appeared on the structures of gold(i) complexes. There has been rather more interest in the stereochemistry of silver(i) two-co-ordinate linear complexes in which the metal co-ordination is sometimes augmented by weak interactions with other potential donor atoms and organometallic w-complexes have both attracted attention. 

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