Electron spin resonance studies of irradiated group 1b metal ions
Electron spin resonance has been used to study the solvation and aggregate formation of silver species in various systems. Studies of silver centres formed in frozen mixtures of both protic and aprotic solvents, after gamma-irradiation at 77 K in a 60Co [special character omitted]source, have been made in an attempt to establish a link between the different types of solvation found in various solvent systems. These studies have also led to the identification of a series of organo-silver adducts. Studies have also been made using a range of nitrogen containing solvents where the detection of 14N super-hyperfine coupling to silver has provided information concerning the arrangement of solvent molecules around the central metal ion. Following this mixed solvent work, the effect of mixed silver salt systems, comprising AgC104 +AgN03 and + Ag2S04 in methyl cyanide, has been studied in order to probe the competition which exists between different anions and solvent molecules as they attempt to coordinate to the silver ion. A section describing the study of various copper (I) and copper (II) salts in methyl cyanide has been included in a study of a series of gold(I) compounds of clinical interest and gold(III) compounds of photographic interest. This has enabled a comparison of certain analogous Cu, Ag and Au species to be made. Complexes of silver with a range of organic olefins have been prepared and studied by e.s.r. after gamma-irradiation, including complexes with cyclohexene, toluene, benzene and but-2-ene. A range of photographic emulsion systems containing sensitising and electron trapping agents have been exposed to blue light and gamma-irradiation, the effects of which have been recorded by e.s.r. Finally, a variable temperature u.v. spectrophotometric method, designed to study samples which have been X-irradiated at 77 K, is described. Included in this section are initial experiments aimed at detecting silver centres and aggregates formed on irradiation, at low temperatures.