Magenta Azomethine Dyes

The most commonly used magenta couplers are l-aryl-5-pyrazolones 32, patented in 1934 [40], The principles for their design and use are the same as that for yellow couplers. In recent years other classes of heterocyclic couplers have been developed. 1/7-Pyrazolo[3,2-c]-l,2,4-triazole couplers 33 and the isomeric 1H-pyrazolo[l,5-6]-l,2,4-triazole couplers have become important because of their sharp absorptions in the green region and their ability to couple efficiently over a wide pH range [41 15], 

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Two kinds of pyrazolotriazole magenta dyes are used in color photographic materials. One is the I //-pyrazolo[5,1 -r]-[l,2,4]triazole skeleton, and the other is the l//-pyrazolo[ 1,5+][ 1,2,4]triazole skeleton as shown in the representative azomethine dye 1 (Figure 1) <1994J(P2)531>. 

N1)-Fused heterocycles have been found of major application as photographic materials. Azomethine dyes are used in conventional three-color (yellow, magenta, and cyan) photographic imaging <1998JAP10264541,... 

To improve the light stability of the original Polacolor film, Polaroid introduced a metallized set of image dyes in 1972. This set included a chromed azomethine yellow 44, a chromed azo magenta 45, and a highly solubilized derivative of copper phthalocyanine 46 [60],... 

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