Synthesis and characterization of a series of hexadecachlorinated phthalocyanines

Several methods known for the preparation of metallated (Al, Co, Li, Si, Zn ) or unmetallated phthalocyanines were explored to synthesize the correspon ding hexadecachlorophthalocyanines. The one pot condensation of tetrachloro phthalic anhydride or tetrachlorophthalonitrile in molten urea in the prese nce or not of a metal salt, led to chlorinated phthalocyanines in 5-36% yie ld depending on the metal. Al and Zn atoms can be inserted in free hexadeca chlorophthalocyanine in 46-80% yield. The substitution of the two lithium a toms of the dilithium phthalocyanine by Al salt get to 68% aluminum phthalo cyanine. All phthalocyanines synthesized were purified and fully characteri zed. H-1, C-13 and Al-27 NMR data were obtained. As a rule, the Q band of t he UV-Vis spectrum displayed a 30 nm bathochromic shift relative to the ban d of unchlorinated compounds. (C) 1999 Elsevier Science S.A. All rights res erved.