Silver complexes isonicotinates

The requirement for atomic-scale sites in the CT mechanism is thought to be due to the formation of adatom-adsorbate complexes. Such complexes require a coordination site on the adsorbate through which the strong interaction can occur, as was demonstrated by the controlled adsorption of isonicotinic acid and benzoic acid on thin island films of silver (see the work of Chen et ai, 1980). This clearly showed that SERS spectra could only be obtained from the molecules when coordinating sites were exposed to the Ag film. 

Silver(n) complexes, 839-850 amino adds, 846 aqua,844,850 biguanides, 849 2,2 -bipyridyl, 843 carboxylates, 844 cinchomeronic acid, 842 dipicolinic acid, 842 dithiocarbamates, 845 isodnchomcronic add, 842 isonicotinates, 840 lutidinic acid, 842 N-heterocyclic ligands, 839 nicotinates, 840 1,10-phenanthroline, 843 phthalocyanines, 848 picolinates, 840... 

Trace amounts of cyanide are usually determined by flow injection spectrophotometric procedures. The target species is first halogenated with chlora-mine-T, after which it reacts with a mixture of pyrazolone or barbituric acid and isonicotinic acid or pyridine to form a bluish-violet polymethine dye. The implementation of gas-diffusion modules in the flow setup for hydrogen cyanide separation avoids matrix interferences and enables the adaptation of inherently nonselective detectors, such as metallic silver-wire electrodes for potentiometric measurements. Total inorganic cyanide, including free and complexed species, such as iron-cyanide complexes, may be determined by sample decomposition with UV irradiation and further photometric or amperometric analysis. 

From a qualitative standpoint, let s note the characterization of isionazid by the formation of a white complex that, by heating in a stream of nitrogen, leads to a deposit of metallic silver and to isonicotinic acid. Evidently, a redox reaction participates in the decomposition. 

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