Silver malonate decomposition

Ihe thermal decomposition of silver malonate [126,127] shows points of similarity with the decomposition of copper(Il) malonate described above [123] and it is useful... 

Decompositions of chemically dissimilar substances (including NiC204, PbCjO, KNj, (NH4)2Crj07) may exhibit similar kinetic behaviour, whereas the decompositions of similar reactants (e.g. oxides) may exhibit apparently unrelated rate characteristics [60]. Decomposition data for very different reactants may be described satisfactorily by the same rate expression, for example the Avrami-Erofeev equation, with n = 2, has been reported as representing the decompositions ofFeC204 [61], KMn04 [29], silver malonate [62], nickel squarate [18], lead citrate [63] and d - LiK tartrate [64] (no common constituents in these six reactants). 

Oxalic and malonic acids, as well as a-hydroxy acids, easily react with cerium(IV) salts (Sheldon and Kochi, 1968). Simple alkanoic acids are much more resistant to attack by cerium(IV) salts. However, silver(I) salts catalyze the thermal decarboxylation of alkanoic acids by ammonium hexanitratocerate(IV) (Nagori et al., 1981). Cerium(IV) carboxylates can be decomposed by either a thermal or a photochemical reaction (Sheldon and Kochi, 1968). Alkyl radicals are released by the decarboxylation reaction, which yields alkanes, alkenes, esters and carbon dioxide. The oxidation of substituted benzilic acids by cerium(IV) salts affords the corresponding benzilic acids in quantitative yield (scheme 19) (Hanna and Sarac, 1977). Trahanovsky and coworkers reported that phenylacetic acid is decarboxylated by reaction with ammonium hexanitratocerate(IV) in aqueous acetonitrile containing nitric acid (Trahanovsky et al., 1974). The reaction products are benzyl alcohol, benzaldehyde, benzyl nitrate and carbon dioxide. The reaction is also applicable to substituted phenylacetic acids. The decarboxylation is a one-electron process and radicals are formed as intermediates. The rate-determining step is the decomposition of the phenylacetic acid/cerium(IV) complex into a benzyl radical and carbon dioxide. 

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