Phthalocyanine Green G

Phthalocyanine Green G (with many commercial names) is a synthetic green pigment of a phthalocyanine dye, which is a complex of copper (II) and chlorinated phthalocyanine. It is a soft green powder and is insoluble in water. It is a bright, high-intensity color used in oily and acrylic artist paints and other applications.

Figure 1. Structure of Phthalocyanine Green G.

Synthesis, properties and production

Phthalocyanine green is derived from phthalocyanine blue by chlorination in the presence of aluminum trichloride. Shows the stoichiometry of complete chlorination:

Cu(C₃₂H₁₆N₈) + 16Cl₂→Cu(C₃₂N₈Cl₁₆)+16HCl

In fact, this pigment is a mixture of isomers and degrees of chloride. The 15th and 16th chlorides are difficult to install. The chemical formula is usually C₃₂H₃Cl₁₃CuN₈ to C₃₂HCl₁₅CuN₈.

Due to the presence of strongly electronegative chlorine substituents, the absorption spectrum is different from that of the parent copper phthalocyanine. Phthalate green is very stable and resistant to alkali, acids, solvents, heat and ultraviolet radiation.

Applications

Due to its stability, phthalocyanine green can be used in inks, coatings and many plastics. It is transparent in the application. Because it is insoluble, there is no tendency to migrate in the material. It is a standard pigment used in the printing ink and packaging industries. Except for eye makeup, all cosmetics are allowed.

Reference:

1. Wojdyla, Michal.; et al. Lock-in phase analysis of copper phthalocyanine photoabsorption spectrum. Optica Applicata. 2005, 35 (3): 561–571.