Silver salts pyrolysis

The pyrolysis of perfluoro carboxylic salts can result both in mono and bimolecular products At 210-220 °C, silver salts give mostly the coupled products, at 160-165 °C in A -methylpyrrolidinone, the corresponding copper salts also give the simple decarboxylated compounds in nearly equal amounts The decomposition of the copper salts m the presence of lodobenzene at 105-125 °C results m a phenyl derivative, in addition to the olefin and coupled product [94] (equations 60-62)... 

Starting materials for the synthesis of all perfluoroalkyl iodonium reagents are the perfluoroalkyl iodides, which themselves play a central role as building blocks in fluoroorganic chemistry. The iodides are available either by pyrolysis of the silver salts of perfluoroalkyl carboxylic acids in the presence on iodine [14] or - on a more technical scale - by iodofluorination of tetrafluoroethylene [15] with the iodine-IFp system [16] and subsequent radical telomerization of tetrafluoroethylene with the resulting intermediate perfluoroalkyl iodides [17] (Scheme 2.143). 

Ethylene has been separated from ethane by a silver nitrate solution passing countercurrent in a hollow fiber poly-sulfone.165 This separation has also been performed with the silver nitrate solution between two sheets of a polysilox-ane.166 A hydrated silver ion-exchanged Nafion film separated 1,5-hexadiene from 1-hexene with separation factors of 50-80.167 Polyethylene, graft-polymerized with acrylic acid, then converted to its silver salt, favored isobutylene over isobutane by a factor of 10. Olefins, such as ethylene, can be separated from paraffins by electroinduced facilitated transport using a Nafion membrane containing copper ions and platinum.168 A carbon molecular sieve made by pyrolysis of a polyimide, followed by enlargement of the pores with water at 400 C selected propylene over propane with an a-valve greater than 100 at 35°C.169... 

During pyrolysis to silver (via silver dicyanamide), initial heating must be slow to avoid explosion [1], High intensity illumination will also cause explosive decomposition of a confined sample [2], Safety precautions for preparation and subsequent use of the explosive salt are detailed [3],... 

However, the reaction products were not, apparently, identified20f. Trifluoro-acetate and trichloroacetate were extracted and precipitated from the acidified solution as their silver and mercurous salts, respectively, and the carbon dioxide produced by pyrolysis of these was analyzed in the mass spectrometer. So the occurrence of side-reactions leading to other carboxylate salts cannot be completely ruled out. Just one possibility is the halodecarboxylation of the anion, followed by hydrolysis of the dihalocarbene or haloform produced, to formate, viz. 

Heterocyclic carboxylic acids have also been decarboxylated by pyrolysis of their calcium, silver, and ammonium salts. 

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