Silver formate, decomposition

AgN03 in cone, solutions, white precipitate—AgCH02, turning dark even in cold, owing to deposition of metallic silver. This decomposition of silver formate does not take place in presence of excess ammonia. 

Silver formate undergoes a decomposition similar to that expressed by the last equation. All the reactions described above are of value in identifying a formate. 

One form of Ag was oriented relative to the original AgNa lattice and the other was not. The decomposition and silver formation was thought to be primarily due to thermal effects, although evidence was found that the form of silver is different in the case of simple thermal decomposition thus irradiation effects play some role in the electron-beam-induced decomposition. These studies are reviewed more fully by Bowden and Yoffe [100]. 

Homogeneous and heterogeneous catalysis of bismethoxycarbonylcarbene addition to olefins and the copper- and silver-catalysed decompositions of dimethyl diazomalonate all result in stereospecific cyclopropanation, although three-membered ring formation is accompained by significant amounts of allyic C—H insertions pro-... 

The presence of hydrogen manifests itself immediately after the oxidation of the organic substance with silver permanganate decomposition product by the formation of small droplets of water condensed on the cool sides of the decomposition tube. 

At room temperature bismuthine rapidly decomposes into its elements. The rate of decomposition increases markedly at higher temperatures (8). Bismuthine decomposes when bubbled through silver nitrate or alkafl solutions but is unaffected by light, hydrogen sulfide, or 4 sulfuric acid solution. There is no evidence for the formation of BiH, though the phenyl derivative, (C H BU, is known. The existence of BiH would not be anticipated on the basis of the trend found with other Group 15 (V) "onium" ions. 

For all three halates (in the absence of disproportionation) the preferred mode of decomposition depends, again, on both thermodynamic and kinetic considerations. Oxide formation tends to be favoured by the presence of a strongly polarizing cation (e.g. magnesium, transition-metal and lanthanide halates), whereas halide formation is observed for alkali-metal, alkaline- earth and silver halates. 

An a-diazo ketone 1 can decompose to give a ketocarbene, which further reacts by migration of a group R to yield a ketene 2. Reaction of ketene 2 with water results in formation of a carboxylic acid 3. The Woljf re arrangement is one step of the Arndt-Eistert reaction. Decomposition of diazo ketone 1 can be accomplished thermally, photochemically or catalytically as catalyst amorphous silver oxide is commonly used ... 

In a DTA study [1193] of decomposition reactions in Ag2C03 + CaC03 mixtures, the presence of a response peak, absent on heating the silver salt alone, resulted in the identification of the double salt Ag2C03 2 CaC03, stable at <420 K. One important general consideration which arises from this observation is that the formation of a new phase, by direct interaction between the components of a powder mixture, could easily be overlooked and, in the absence of such information, serious errors could be introduced into attempts to formulate a reaction mechanism from observed kinetic characteristics. Due allowance for this possibility must be included in the interpretation of experimental data. 

In summary thermal decomposition of chlorinated phenols does not generally lead to dioxins. There are, however, several conditions which by themselves or combined would favor dioxin formation. First, of all chlorinated phenols either in bulk or in solution, only pentachlorophenol produced measurable amounts of dioxin. Secondly (Table II), only sodium salts in salid state reactions produced dioxins in reasonable yields. In contrast, the silver salt of pentachlorophenol (Figure 8) undergoes an exothermic decomposition at considerably lower temperatures and produced only higher condensed materials. No dioxin was detected. 

A kinetic study of the previously reported substitution of aromatic nitro groups by tervalent phosphorus has established an aromatic 5n2 mechanism. Similarities in values of activation energies, and in relative reactivities of phosphite and phosphonite esters, between this displacement and the Arbusov reaction suggest a related mechanism (31), while the lack of reactivity of p-dinitrobenzene is attributed to the need for intramolecular solvation (32). The exclusive formation of ethyl nitrite, rather than other isomers, is confirmed from the decomposition of triethoxy-(ethyl)phosphonium fluoroborate (33) in the presence of silver nitrite. A mechanism involving quinquevalent phosphorus (34) still seems applicable, particularly in view of the recent mechanistic work on the Arbusov reaction. ... 

A strongly coupled surface complex between a formate ion and adsorbed formic acid is the decomposition intermediate on silver (58). 

The relative decomposition temperatures for the formate, 7, on the clean metals (M) can be related to the surface metal-oxygen and metal-hydrogen bond strengths listed in Table V. With the exception of silver, TJ, decreased... 

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