Red carbocyanine dyes for spectrally sen - sitising silver halide photographic emulsions

摘要

Red carbocyanine dyes (I) for spectrally sensitising Lippmann type photographic silver halide emulsions: (where R1 and R2 are each oft. substd. alkyl, aralkyl, aryl, or cycloalkyl, or alkyl; R3 is oft. substd. alkyl, aralkyl, aryl, or allyl; R4 is alkoxy or oft. substd. amino; R5 is H, or oft. substd. alkyl, aryl or aralkyl; Z1 and Z2 each represent the non-metallic atoms required to form oft. substd. thiazole, benzothiazole, naphtholkiazole, selenazole, benyoselenazole, or naphthoseleriazole rings; and X- represents an anion, when R1, R2 or R3 do not contain an anionic group).