Silver characterized

The desilvering speed of an electrolytic silver recovery unit can be characterized by two parameters. 

A third group includes silver—nickel, silver—cadmium oxide, and silver—graphite combinations. These materials are characterized by low contact resistance, some resistance to arc erosion, and excellent non sticking characteristics. They can be considered intermediate in overall properties between silver alloys and silver or copper—refractory compositions. Silver—cadmium oxide compositions, the most popular of this class, have wide appHcation in aircraft relays, motor controllers, and line starters and controls. 

Silver bromide crystals, formed from stoichiometric amounts of silver nitrate and potassium bromide, are characterized by a cubic stmcture having interionic distances of 0.29 nm. If, however, an excess of either ion is present, octahedral crystals tend to form. The yellow color of silver bromide has been attributed to ionic deformation, an indication of its partially covalent character. Silver bromide melts at 434°C and dissociates when heated above 500°C. 

Although no acyl hypochlorites [RCO2CI] have been isolated in pure form, they have been characterized in solution and employed as reactants via in situ generation from CI2O or HOCl and carboxyUc acids, or from CI2 and silver salts of carboxyUc acids (246,247). Perfluoroacyl hypochlorites have also been prepared (248). 

The use of azide reagents is also important for the synthesis of cyclic sulfur(VI)-nitrogen systems. The reaction of SOCI2 with sodium azide in acetonitrile at -35°C provides a convenient preparation of the trimeric sulfanuric chloride [NS(0)C1]3 (Eq. 2.16). " Thionyl azide, SO(N3)2 is generated by the heterogeneous reaction of thionyl chloride vapour with silver azide (Eq. 2.17). This thermally unstable gas was characterized in situ by photoelectron spectroscopy. The phenyl derivative of the six-membered ring [NS(0)Ph]3 can be prepared from lithium azide and PhS(0)Cl. ... 

Iodide ions reduce Cu to Cu , and attempts to prepare copper(ll) iodide therefore result in the formation of Cul. (In a quite analogous way attempts to prepare copper(ll) cyanide yield CuCN instead.) In fact it is the electronegative fluorine which fails to form a salt with copper(l), the other 3 halides being white insoluble compounds precipitated from aqueous solutions by the reduction of the Cu halide. By contrast, silver(l) provides (for the only time in this triad) 4 well-characterized halides. All except Agl have the rock-salt structure (p. 242). Increasing covalency from chloride to iodide is reflected in the deepening colour white yellow, as the... 

Ozin and Huber 112) synthesized and characterized very small silver particles, Ag n = 2-5) by conventional deposition methods, as well as by a novel technique that they have termed "cryophotoaggrega-tion. This study will be discussed in detail in Section III. Of interest here is a study of silver atoms and small, silver clusters entrapped in ice and high-molecular-weight paraffin (n-C22H46, n-C32Hg8) matrices 146) (see Figs. 7 and 8, and Tables IV and V). Besides the intriguing, multiple-site (solvation) occupancy of atomic silver in ice matrices, and their thermal and photochemical interconvertibility, their extremely... 

We have studied the steady-state kinetics and selectivity of this reaction on clean, well-characterized sinxle-crystal surfaces of silver by usinx a special apparatus which allows rapid ( 20 s) transfer between a hixh-pressure catalytic microreactor and an ultra-hixh vacuum surface analysis (AES, XPS, LEED, TDS) chamber. The results of some of our recent studies of this reaction will be reviewed. These sinxle-crystal studies have provided considerable new insixht into the reaction pathway throuxh molecularly adsorbed O2 and C2H4, the structural sensitivity of real silver catalysts, and the role of chlorine adatoms in pro-motinx catalyst selectivity via an ensemble effect. 

Archibald, S.J., Alcock, N.W., Busch, D.H. and Whitcomb, D.R. (2000) Synthesis and characterization of silver(I) complexes with C-AIkyl functionahzed N,f/-Diphenylamidrnates Tetrameric and trrmeric structural motifs. Journal of Cluster Science, 11, 261—283. 

Catalano, V.J. and Horner, S.J. (2003) Luminescent gold(l) and silver(l) complexes of 2-(diphenylphosphino)-l-methylimidazole (dpim) Characterization of a three-coordinate Au(l)-Ag(l) dimer with a short metal-metal separation. Inorganic Chemistry, 42, 8430-8438. 

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