phthalocyanine

References

phthalocyanine

chemical compound

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 23, 2026

Quick Summary

Phthalocyanine is a bright greenish-blue crystalline compound, with the chemical formula C₃₂H₁₈N₈. It is also used to describe metal derivatives that function as brilliant, fast blue to green dyes or pigments.1

Phthalocyanines are significant 20th-century colorants, analogous to natural porphyrins like chlorophyll and hemoglobin. They were discovered in the early 20th century, but their potential as colorants was recognized later, leading to their commercial availability in the 1930s. Copper phthalocyanine is the most important metal complex, primarily used as a pigment but also applicable to certain fabrics. These compounds are known for their remarkable chemical stability, strong color, and excellent lightfastness, making them cost-effective for various applications. Phthalic acid, a related compound, is a key ingredient in the production of phthalocyanine pigments.23

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

3 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

coordination compound
Coordination compounds in industry
Phthalocyanine complexes (e.g., copper phthalocyanine), containing large-ring ligands closely related to the porphyrins, constitute an important class of dyes for fabrics.
Read More
Phthalocyanine complexes (e.g., copper phthalocyanine), containing large-ring ligands closely related to the porphyrins, constitute an important class of dyes for fabrics.
Read More

heterocyclic compound
Five-membered rings with one heteroatom
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).
Read More
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).
Read More

pigment
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.
Read More
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.
Read More

dye
Phthalocyanine compounds
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…
Read More
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…
Read More