Structural relationship between phthalocyanines (Pcs) and porphyrins, Phthalocyanines are tetrabenzoporphyrins with substituting four meso-carbons in position ?-? and ?-? axis of the porphyrin by four nitrogen atoms. In other words, Phthalocyanines are tetraazaporphyrins (porphyrazines) with four addition benzene groups (Scheme 1) (Leonardo et al. 2008)
Phthalocyanines can be Synthesized by different routes according to the kind of
Phthalocyanines to be created; metal-free, symmetrical or asymmetrical
Phthalocyanine. Synthetic Phthalocyanines based on many factors: solvent (high
boiling point solvents), precursor metal salt (metals, sulphates, halides, metal salts and
oxides), temperature (to facilitate melting of the precursor and rapid
cyclotetramerization) , catalyst and base. Pcs is formed through cyclotetramerization
of phthalimide, phthalic acids, phthalonitrile precursors, phthalic anhydrides in the
presence of a metal salt and in the absence of a metal salt for un metallated Pcs
(Scheme 2) (Rodriguez-Morgade. de la Torre et al .2003; Louati et al. 1985).