SILVER HALIDE EMULSIONS SENSITIZED WITH METHINE DYES CONTAINING A CYCLOPENTANONE NUCLEUS

摘要

Novel cyanine dyes containing a cyclopentanone nucleus in the methine chain are prepared by the acid hydrolysis of cyanine enamine derivatives. These cyanine dyes are spectral sensitizers for photographic silver halide emulsions. A number of the new dyes extend the sensitivity of photographic silver halide emulsions into the red and near infra-red regions of the spectrum.