Silver compounds structure

The complexes [M(/i-C7H4NS2)(COD)]2 (M = Rh, Ir) and [Rh(/i-C7H4NS2)(CO)(PPh3)]2 react with silver compounds to give the heterometallic derivatives with the silver(I) atoms bonded to the thiolate sulfur atoms. The structure of [Rh2Ag2(/i3-C7H4NS2)2(C104)] shows a short Rh—Ag distance.1010... 

Although the abundance of silver in the Earth s crust is comparatively low (0.07 pgg-1), it is considered an environmental contaminant and is toxic at the nanomolar level. As an environmental pollutant it is derived from mining and smelting wastes and, because of its use in the electrical and photographic industries, there are considerable discharges into the aquatic environment. Consequently, there have been studies on the geochemistry and structure of silver-sulfur compounds [31]. Silver, either bound to large molecules or adsorbed on to particles, is found in the colloidal phase in freshwater. In anoxic sediments Ag(I) can bind to amorphous FeS, but dissolved silver compounds are not uncommon. A more detailed study of silver speciation in wastewater effluent, surface and pore waters concluded that 33-35% was colloidal and ca. 15-20% was in the dissolved phases [32]. 

It is noteworthy that the corresponding silver compounds do not exist in this structure. AgLuS2 (468), which we expect to be non-metallic, crystallizes in a disordered NaCl structure (high-temperature modification ). The structure of AgYS2, on the other hand, is a monoclinic, strongly distorted but ordered version of the rocksalt type (468). 

Thus increased covalent bonding resulting from Fajans-type phenomena can lower the transition temperatures. For example, the alkali halides (except CsCl, CsBr, and Csl) and the silver halides (except Agl) crystallize in the NaCl structure. The sizes of the cations are comparable Na = 116 pm, Ag = 129 pm, K = 152 pm, yet the melting points of the halides are considerably different (Table 8.6). The greater covalent character of the silver halide bond (resulting from the electron configuration) compared with those in the alkali halides helps stabilize discrete AgX molecules in the liquid and thus makes the melting points of the silver compounds lower than those of the potassium compounds. A similar comparison can be made between the... 

Trithiane, S3(CH2)3 a chair-shaped molecule like cyclohexane, forms many metal complexes. Two silver compounds have layer structures based on the 6-gon net. In both structures Ag is tetrahedrally coordinated, the fourth ligand (X in Fig. 3.23(a)) being H2O in Ag(trithiane)C104. H2O and 0 of NOJ in Ag(tri-thiane)N03. H2O (JCS A 1968 93). Silver tricyanmethanide, Ag[C(CN)3], has a... 

The experimental techniques and theoretical interpretations of PES data have been discussed in detail in numerous articles and books. Some detailed reviews were published recently in this series1. Other reviews are too numerous to list so we shall mention only some of the more recent ones2-4. Our aim is not to give a detailed coverage of PES, but rather to provide a summary of PES methods which were used in studies of the electronic structure of gold and silver compounds. What all PES methods have in common is the basic phenomenon of photoionization, in which a photon of known energy hv becomes absorbed by the material and induces subsequent ejection of an electron (photoionization). The law of conservation of energy applied to the process can be expressed by equations 1 and 2,... 

A pronounced effect of a water molecule on the solid state structure of the AgN(S02Me)2 compound has been shown. Many silver compounds are light sensitive and hence often no X-ray crystallographic information is available for them. 

The variation of colour in silver compounds including sulphamides has been correlated with structure. The colour changes go from colourless to red, depending on the number of silver(I) atoms coordinating the donor atoms of the bases used318. Ag(I) sulphamides show different colours depending on the stoichiometry, disilver sulphamides are colourless, trisilver sulphamides are deep red. 

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