Silver oxide initiator

Oxidation States. The common oxidation state of silver is +1, ie,, as found in AgCl, which is used with Mg in sea- or freshwater-activated batteries (qv) AgNO, the initial material for photographic materials, medical compounds, catalysts, etc and silver oxide, Ag20, an electrode in batteries (see Silver compounds). Few compounds are known. The aqua ion [Ag(H2 O), which has one unpaired electron, is obtained... 

The manufacture of silver nitrate for the preparation of photographic emulsions requires silver of very high purity. At the Eastman Kodak Company, the principal U.S. producer of silver nitrate, 99.95% pure silver bars are dissolved in 67% nitric acid in three tanks coimected in parallel. Excess nitric acid is removed from the resulting solution, which contains 60—65% silver nitrate, and the solution is filtered. This solution is evaporated until its silver nitrate concentration is 84%. It is then cooled to prepare the first crop of crystals. The mother Hquor is purified by the addition of silver oxide and returned to the initial stages of the process. The cmde silver nitrate is centrifuged and recrystallized from hot, demineralized water. Equipment used in this process is made of ANSI 310 stainless steel (16). 

Therefore, the use of several specific techniques while implementing the method of semiconductor sensors makes it feasible to detect and analyze emission of oxygen atoms at initial stage of metal oxidation although in case of silver it should be noted that there are no phase of silver oxide formed due to its instability at such conditions [57]. Rather, the absorption of oxygen by silver would be related to dissolution and internal oxidation. 

During preparation of an oxidising agent on a larger scale than described [1], addition of warm sodium hydroxide solution to warm ammoniacal silver nitrate with stirring caused immediate precipitation of black silver nitride which exploded [2], Similar incidents had been reported previously [3], including one where explosion appeared to be initiated by addition of Devarda s alloy (Al—Cu—Zn) [4], The explosive species separates at pH values above 12.9, only produced when alkali is added to ammoniacal silver solutions, or when silver oxide is dissolved with ammonia [5], The Sommer Market reagent mixture used to identify cellulose derivatives led to a severe explosion [6],... 

Interaction of chlorine with methane is explosive at ambient temperature over yellow mercury oxide [1], and mixtures containing above 20 vol% of chlorine are explosive [2], Mixtures of acetylene and chlorine may explode on initiation by sunlight, other UV source, or high temperatures, sometimes very violently [3], Mixtures with ethylene explode on initiation by sunlight, etc., or over mercury, mercury oxide or silver oxide at ambient temperature, or over lead oxide at 100°C [1,4], Interaction with ethane over activated carbon at 350°C has caused explosions, but added carbon dioxide reduces the risk [5], Accidental introduction of gasoline into a cylinder of liquid chlorine caused a slow exothermic reaction which accelerated to detonation. This effect was verified [6], Injection of liquid chlorine into a naphtha-sodium hydroxide mixture (to generate hypochlorite in situ) caused a violent explosion. Several other incidents involving violent reactions of saturated hydrocarbons with chlorine were noted [7],... 

The sequence of reactions leading to compound 83 by an elimination that liberates the aldehyde 82, which is immediately reduced to 83, is depicted. This result also explains the formation of 43 by Purdie-Irvine methylations of 4 (Ref. 29) and 33 (Ref. 24) in both, moist silver oxide is the base, and it initiates elimination followed... 

Contact with metal oxides increases the sensitivity of nitromethane, nitroethane and 1-nitropropane to heat (and of nitromethane to detonation). Twenty-four oxides were examined in a simple quantitative test, and a mechanism was proposed. Cobalt, nickel, chromium, lead and silver oxides were the most effective in lowering ignition temperatures [1]. At 39 bar initial pressure, the catalytic decomposition by chromium or iron oxides becomes explosive at above 245° C [2],... 

Using a similar solution, films of either Ag or AgO were deposited on both glass and polyester film [41]. Addition of triethanolamine to a Ag solution caused initial precipitation (silver oxide or hydroxide), which redissolved in excess triethanolamine. Deposition from a solution where some precipitate remained resulted in AgO (possibly with some Ag20), while a solution where this precipitate was completely redissolved gave metallic Ag. The reducing action of the free triethanolamine present in the latter case may be the cause of the formation of metallic Ag. 

Methyl Ethers. Methylation of sucrose is generally conducted under basic conditions. Etherification occurs initially at the most acidic hydroxyl groups, HO-2, HO-T, and HO-3f, followed by the least hindered groups, HO-6 and HO-6. Several reagents have found use in the methylation of sucrose, including dimethyl sulfate—sodium hydroxide (18,19), methyl iodide—silver oxide—acetone, methyl iodide—sodium hydride in N, N- dimethyl form amide (DMF), and diazomethane—boron trifluoride etherate (20). The last reagent is particularly useful for compounds where mild conditions are necessary to prevent acyl migration (20). 

Very sensitive to contact with hard objects, exploding when moist. An extremely sensitive explosive when dry, initiable by friction, impact or heating. The impure product produced by allowing ammoniacal silver oxide solution to stand seems even more sensitive, often exploding spontaneously in suspension. 

Silver salts are well established to promote atom transfer reactions.1-5 In 1946 Bachmann and coworkers reported that silver oxide facilitated the Wolff rearrangement6 of a-diazocarbonyl compounds.7 After this initial report, several other silver(I) reagents (including AgN03 and Ag02CPh)8,9 were identified to provide higher yields,... 

Further studies on the photochemistry of friedelin have led to the isolation of the unsaturated aldehyde (130).105 Silver oxide oxidation of (130) gave the known putranjivic acid. Irradiation of friedelin in the presence of acetone afforded the hydroxy-ketone (131).106 Photochemically initiated reaction of 7/3-hydroxyfriedelane and 3/3,7/3-dihydroxyfriedelane with lead tetra-acetate-iodine... 

Hoffmann degradation is a classic way to transform aporphines into phe-nanthrene alkaloids. This transformation involves the thermolysis of the quaternary ammonium hydroxide formed by sequential treatment of an aporphine with an alkylating agent and silver oxide. This degradation was extensively used in initial degradative studies of the structure of aporphines. The alkylations are usually done with methyl iodide (20,30,45,60,85,86,88) or dimethyl sulfate... 

The cyclic voltammogram of Ag deposition/solution on carbons with preadsorbed silver in the 0.05 M NaNO + 0.05 M AgNOj solution is shown in Fig. 52. In relation to the initial carbons (Fig. 48), a taller silver oxidation peak for the D—H carbon and a shorter one for the D—Ox are recorded however, in the case of the D—N carbon, this peak almost completely disappears. This indicates that silver deposition on D—H carbon is easier if it has previously been covered with a metallic silver layer. This behavior is a typical example of the nucleation and growth during electrodeposition [302]. The different behavior of the D—N carbon is indicative of another kind of interaction (such as complex formation) between silver and surface functional groups. 

Many of the oxidants employed to prepare aldehydes from primary alcohols may be used to further oxidize the aldehyde initially formed to the corresponding carboxylic acid. The most common oxidants for this purpose include KMn04," chromic acid, sodium chlorite,silver oxide," and PDC in DMF. °... 

---