Silver diammine

Rabflloud T. A comparison between low background silver diammine and silver nitrate protein stains. Electrophoresis 1992 13 429-39. 

The master is coated with a dilute solution of silver diammine complex—[Ag(NH3)2]" —foUowed... 

The seeds of this ornamental shrub yielded three alkaloids which appear to be a triacetate, a tetraacetate, and a pentaacetate, respectively. They are A, C27H36O12N (m.p. 258-260°, [a] - -21°), B, C29H37O13N (m.p. 288-290°, [a] D +14°), and C, C31H39O14N (m.p. 164-168°, [a] d +8°), there being some uncertainty regarding the empirical formulas, although A and B are convertible to C on acetylation. They are rapidly decomposed by strong alkali and reduce silver diammine solutions (51). 

Carboplatin (96) is significantly less toxic in the clinic than cisplatin. Most particularly, it is much less nephrotoxic. Use of a bidentate ligand also ensures formation of a ds complex. Its synthesis begins with cis-diammine platinum diiodide (94) which is reacted with silver sulfate to give cis-diaquodiam mine platinum sulfate (95). This is reacted with the barium salt of 1,1-cyclo-butanedicarboxylic acid to yield carboplatin [23],... 

Many platinum analogs, and analogs based on other metal centres, have been prepared and evaluated. Carboplatin (7.89, cA-diammine(l,l cyclobutanedicarboxalato)platinum) has markedly reduced gastrointestinal and renal toxicity in comparison with cisplatin. It is prepared by the treatment of cA-Pt(NH3)2l2 with silver sulphate, followed by the barium salt of 1,1-cyclobutanedicarboxylic acid. 

Monammino-silver Chloride, [Ag(NH3)]Cl.—Biltz and Stollen-werk5 report the existence of the monammine, and state that sesqui-annuino- and nionammino-silver chloride form mixed crystals at 30° C., whilst Bodlilnder and Fittig8 have shown that a solution of silver chloride in aqueous ammonia contains the diammine in solution even when solid sesquiammine has separated from the liquid. A certain amount of doubt, therefore, surrounds the existence of the monammine and the diammine of silver chloride, although both appear to exist in aqueous ammoniaeal solution. 

Ammino-silver Bromides.—Silver bromide, like the chloride, unites with ammonia the triammine, [Ag(NH3)3]Br, the sesquiammine, [Ag2(NH3)a]Br2 or 2AgBr.8NII3, the diammine, [Ag(NH3)2]Br, and the monammine, [Ag(NH3)]Br, have all been obtained. 

Triammino-silver Nitrate, [Ag(NH3)3]N03.—The compound is formed when silver nitrate is exposed to dry ammonia gas much heat is developed, increase in bulk takes place, and sufficient heat may he produced to fuse the mass.3 It exhibits considerable heat of formation, is soluble in water, and loses ammonia on heating, dissociating at 63° C. under ordinary pressure, and is soluble in liquid ammonia below —10° C.4 Only the diammine exists in solution, the triammine being completely dissociated into the diammine and ammonia. 

Classical methods of group analysis and separation take advantage of the stability of the [Ag(NH3)2]+ ion to separate silver from mercury. Treatment of a precipitate containing AgCl with dilute ammonia leads to the reaction in equation (3) bringing the silver into solution. To confirm the presence of Ag+, nitric acid must then be added to cause reprecipitation of AgQ. In aqueous ammonia, the diammine was the highest species formed, and thermodynamic data for its formation are collected in Table 3.20-23... 

Table 4 Observed Frequencies (cm-1) in Raman Spectra of Saturated Aqueous Solutions of Diammine Silver(I) Complexes30...

IR and Raman studies of some diammine silver(I) salts and their deuterated derivatives have been reported.30,31 Characteristic absorption bands are given in Tables 4 and 5. 

To a solution of 75g of silver nitrate in 200 ml of water is added a solution of 25g of ammonium chloride in an equal volume of water. The precipitated silver chloride is washed repeatedly by decantation with water and dissolved in the minimum volume of cold 20% aqueous ammonia (10 volumes of 28% ammonia and 4 volumes of water) about 500ml should be required, The diammine silver solution should be used without delay in the next step. 

If ammonia is added, silver chloride dissolves in the form of the diammine-argentate ion ... 

The precipitate is insoluble in ammonium sulphide, ammonium polysulphide, ammonia, potassium cyanide, or sodium thiosulphate. Silver sulphide can be precipitated from solutions containing diammine-, dicyanato- or dithiosulphato-argentate complexes with hydrogen sulphide. 

Hydrazine sulphate (saturated) when added to a solution of diammine-argentate ions, forms finely divided silver metal, while gaseous nitrogen is evolving ... 

Silver(l) will dissolve forming the diammine complex ... 

The Ag" ions are precipitated from the alkaline solution as Ag70 and redissolve as the diammine silver complex. The hydrazine reduces the silver ions to metallic silver. 

Two grams (0.005 mole) of (-)389-bis(l,2-ethanediamine)oxalatocobalt(lII) iodide3 is suspended in 30 mL of water at 35°, 0.81 g (0.005 mole) of silver acetate is added, and the mixture is stirred for five minutes at 35°. The mixture is then filtered and the precipitated silver halide is washed with 5 mL of warm water (50°). Separately, 2.4 g (0.01 mole) of sodium ciff.m-diammine-carbonato-dicyanocobaltate(UI) dihydrate is dissolved in 10 mL of water. The solution is added to the filtrate and combined with the washings. After removal of the precipitated material, the mixed solution is kept in a refrigerator, whereupon an orange diastereoisomer of the (+ )5g9 form of the carbonato complex precipitates. The product is collected on a filter and washed with cold water. Recrystallization is repeated from water until the CD peak at 24,100 cm-1 reaches a constant value. The crystals are collected on a filter, washed with 50% cold, aqueous methanol, ethanol, and diethyl ether, and finally dried under vacuum. The yield is 0.3 g. Anal. Calcd. for [Co(ox)(en)2][Co(CN)2(C03)(NH3)2]-2H20 C, 21.44 H, 5.16 N, 22.05. Found C, 21.31 H, 5.25 N, 21.78. 

Three grams (0.0075 mole) of (-)589-bis(l,2-ethanediamine)oxalatocobalt(III) iodide1 is suspended in 20 mL of water at 50°. To it 0.225 g (0.0075 mole) of silver acetate is added, and the mixture is stirred for five minutes at 50°. The resulting solution is filtered and the precipitated silver halide is washed with 5 mL of warm water at 50°. To the hot filtrate (combined with the washings) is added 4.4 g (0.015 mole) of sodium cis.cis-diammine-dicyano-oxalatocobal-... 

Essentially, all the silver exists as the diammine complex in 0.10 M ammonia. 

Table 5 Observed Frequencies (cm ) in the IR Spectra of some Diammine Silver(I) Salts and...

Dithionites reduce diammine silver nitrate to silver, which is dissolved in nitric acid and the solution titrated against standardised thiocyanate solution. 

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