phthalocyanine

Phthalocyanine complexes (e.g., copper phthalocyanine), containing large-ring ligands closely related to the porphyrins, constitute an important class of dyes for fabrics.

The phthalocyanines are a group of synthetic pigments that contain four isoindole units linked together in a large ring. A typical member of the family is phthalocyanine blue (Monastral Fast Blue).

Copper phthalocyanines provide brilliant, strong blues and greens that are unusually colourfast for organic colours. Some pigments, such as fluorescent ones, are simply dyes that have been rendered insoluble by chemical reaction.

Phthalocyanines, the most important chromogens developed in the 20th century, were introduced in 1934. They are analogs of two natural porphyrins: chlorophyll and hemoglobin. Phthalocyanine was discovered in 1907 and its copper salt in 1927, but their potential as colorants was not immediately…