Color photography metallized dyes

Hydroxy-2-Naphthalenecarboxylic Acid. l-Hydroxy-2-naphthoic acid is made similarly to the isomer (2-hydroxy-1-naphthoic acid) by reaction of dry sodium 1-naphthalenolate with CO2 in an autoclave at ca 125°C. It has been used in making triphenylmethane dyes and metalli able a2o dyes. Alkylamides and arylamides of l-hydroxy-2-naphthalenecarboxyhc acid are cyan couplers, ie, components used in indoaniline dye formation in color films (see Color PHOTOGRAPHY). 

Formazan, l-(2-hydroxy-5-suIfophenyl)-3-phenyl-5-(2-carboxyphenyl)-zinc detection, 6, 83 Formazans cobalt complexes dyes, 6, 81 metal complexes bidentate, 6, 78 color photography, 6,111 dyes, 6, 77 tetradentate, 6, 81 tridentate, 6, 79... 

The development of new and improved dyes based on pyrazolinone structures has likewise led to modem developments of no inconsiderable magnitude. The use of tartrazine as an approved color for foodstuffs is of significance. The development of pyrazolinone dyes for use as magenta couplers and sensitizers in color photography and in metal chelate dye structures has established a renewed, modem interest in these dyes. The chelating characteristics, which will be of continuing theoretical structure interest in coordination chemistry, have been used in developing picrolonates (salts of 3-methyl-4-nitro-l-p-nitrophenyl-2-pyrazolin-5-one) of possible utility in analytical procedures. 

In the traditional silver halide dye-forming and dye-bleach processes, metal complex dyes are not normally used.62,63 However, metal complex azo dyes have been claimed15 for use in color diffusion transfer photography employing non-diffusible magenta dye-releasing dyes which, upon development of the silver halide layer, release a diffusible magenta dye (Scheme 7). 

Other types of metal complex azo dyes described for color diffusion transfer photography include pyridylazonaphthols6 (70) and pyridylazo aminophenols65 (71). 

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