Phthalocyanine forms upon heating phthalic acid derivatives that contain nitrogen functional groups. Classical precursors are phthalonitrile and diiminoisoindole. In the presence of urea, the heating of phthalanhydride is a useful route to H2Pc.
Phthalocyanine has been widely exploited in industry and academia, in a variety of applications ranging from conventional dye stuffs to catalysis.
Phthalocyanine and its derivatives finds applications in artificial organic pigments and almost 25 % of organic dyes are comes under this phthalocyanine group.
These dyes find extensive use in various areas of textile dyeing (Direct dyes for cotton), for spin dyeing and in the paper industry. These dyes are different verities and known with their commercial names.
Direct blue 86 is the sodium salt of CPC-sulfonic acid whereas direct blue 199 is the quaternary ammonium salt of the CPC-sulfonic acid. The quaternary ammonium salts of these sulfonic acids are used as solvent dyes because of their solubility in organic solvents. The dye derived from cobalt phthalocyanine and an amine is Phthalogen Dye IBN. 1,3-Diiminoisoindolene, the intermediate formed during phthalocyanine manufacture, used in combination with a copper salt affords the dye GK 161.
All major artists pigment manufacturers produce variants of copper phthalocyanine, designated color index PB15 (blue) and color indexes PG7 and PG36 (green).
This compound is also used for coatings of read/write CD-ROM’s. This is an increasingly important topic in the information storage industry – read/write cd-rom technology at low cost has obvious implications for the computer, education and communications industries.
Many types of chemical sensor based on phthalocyanines have been proposed – including thin film resistive devices, FET sensors and Langmuir-Blodgett films.
It is also used as an anti-cancer agent. The fluoraluminium phthalocyanine has been extensively studied for potential use as a target molecule in anti-cancer treatment.
There is evidence that exposure to phthalocyanines can cause serious birth defects in developing embryos.