Synthesis and characterization of imidazole substituted phthalocyanines

Phthalocyanines that possess interesting physical and chemical properties, have been widely used in many areas such as prepared of semiconductor materials, gas sensors, photodynamic cancer therapy, catalysis, solar cells, optic discs, electrochromic materials. On the other hand, imidazole and its derivatives have been attracted attention as to their optical, electronic and catalytic properties. Therefore, they will be interesting that prepared and characterized of phthalocyanines containing imidazole derivatives on periferal position which will be had properties of electrical, optical and gas sensing.In the present work, imidazole monosubstituted phthalonitrile 1 was prepared by the reaction of 4-nitrophthalonitrile and 4,5-diphenyl-1H-imidazolethiole in the presence of K2CO3. Tetrasubstituted metal-free monophthalocyanine 2 was obtained by the tetramerization of compound 1 with metalic lithium and then its acidic hydrolysis. Tetrasubstituted metallo monophthalocyanines 3 and 4 were obtained by the reaction of compound 1 with ZnCl2 or CoCl2 in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Tetrasubstituted sandwich phthalocyanines 5 and 6 were synthesized by the reaction of compound 1 with Lu(OAc)3.nH2O or Eu(OAc)3.nH2O in the presence of DBU. Imidazole disubstituted phthalonitrile 7 was prepared by the reaction of 4,5-dichlorophthalonitrile and 4,5-diphenyl-1H-imidazolethiole in the presence of Na2CO3. Octasubstituted metal-free monophthalocyanine 8 was obtained by the tetramerization of compound 7 in hydroquinone. Octasubstituted metallo monophthalocyanines 9 and 10 were obtained by the reaction of compound 7 with ZnCl2 or CoCl2 in the presence of DBU. Octasubstituted sandwich phthalocyanines 11 and 12 were synthesized by the reaction of compound 7 with Lu(OAc)3.nH2O or Eu(CF3SO3)3 in the presence of DBU.Prepared compounds were characterized by 1H-NMR, 13C-NMR, UV-VIS, IR, mass, ESR spectrometers and elemental analysis. The aggregation behaviors of tetra- and octa- substituted monophthalocyanines were studied depend on solvents and concentrations.KEY WORDS: Phthalocyanine, Sandwich Phthalocyanine, Imidazole, Zinc, Cobalt, Lutetium, Europium, Aggregation.