Agricultural Uses
Phthalocyanine is a group of benzoporphyrins which
have strong pigmenting power, forming a family of dyes.
The basic structure of the molecule comprises four
isoindole groups (C6H4,)C2N, joined by four nitrogen
atoms. Four commercially important modifications are:
(a) metal free phthalocyanine (C6H4C2N)4, having a bluegreen
color,(b copper phthalocyanine in which a copper
atom is held by secondary valences of the isoindole
nitrogen atoms, (c) chlorinated copper phthalocyanine,
green, in which 15 to 16 hydrogen atoms are replaced by
chlorine, and (d) sulphonated copper phthalocyanine,
water-soluble and green, in which two hydrogens are
replaced by sulphonic acid groups. It is used in decorative
enamels and automotive finishes; chlorophyll and
haems have basic phthalocyanine structures in their
molecules.
Purification Methods
Purify phthalocyanine by sublimation (two to three times) in an argon flow at 300-400Pa; and similarly for the Cu(II), Ni(II), Pb(II), VO(II) and Zn(II) phthalocyanine complexes. [Beilstein 26 III/IV 4255.]