Imaging compounds photography

Na[AuClJ, per mole of silver haHde. Coordination compounds are used as emulsion stabilizers, developers, and are formed with the weU-known thiosulfate fixers. Silver haHde diffusion transfer processes and silver image stabilization also make use of coordination phenomena. A number of copper and chromium azo dyes have found use in diffusion transfer systems developed by Polaroid (see Color photography, instant). Coordination compounds are also important in a number of commercial photothermography and electrophotography (qv) appHcations as weU as in the classic iron cyano blueprint images, a number of chromium systems, etc (32). 

We start the discussion of the group (2) of photo-de-diazoniations in imaging processes by noting that, after silver halide photography, systems based on the photolysis of diazo compounds form the second most important group of imaging processes. 

Use Textiles, manufacture rayon, rubber, fertilizers, refrigeration, condensation polymerization, photography (development of latent images), pharmaceuticals, ammonia soaps, lubricants, fireproofing wood, ink manufacture, explosives, ceramics, ammonium compounds, saponifying fats and oils, organic synthesis, detergents, food additives, household cleanser. 

A substance used in photography to convert a latent image to a visible one by chemical reduction of a silver compound to metallic silver more rapidly in the portions exposed to light than in those not exposed. Such reducing agents as hydroquinone, pyrogallol, and p-phenylenediamine are used. 

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