Synthesis and characterization of 7-hydroxycoumarin containing new type of phthalocyanine compounds and investigation of thermal and electrochemical properties

To synthesized and evaluate the variation of the properties of phthalocyanines with both the position of the substituents and the type of metal used for coordination, tetrasubstituted nickel, cobalt, zinc, copper, chromium and Iron, phthalocyanines bearing 7-hydroxycoumarin as substituents were synthesized by the cyclotetramerization reaction of the synthesized phthalonitrile derivatives and 1,3-diiminoisoindoline. The structures of the synthesized compounds were characterized by a combination of 1H NMR, 13C NMR, UV-Vis, and FT-IR spectrophotometry. The electronic spectra of nickel, cobalt, zinc, copper, ıron, chromium phthalocyanine compounds (NiPc, CoPc, ZnPc, CuPc, FePc, CrPc) in DMF are given. The UV-Vis absorption spectra of ZnPc, CuPc, NiPc, and CrPc, in DMF, showed intense Q absorption at 690nm. The Q band absorptions were also observed at 677 nm and 678 nm, respectively, for CoPc, and FePc. The thermal stability of the phthalocyanine derivatives were checked by TGA and then the phthalocyanines were heated up to 700 oC to determine their degradation temperature. The temperatures at which the phthalocyanine began to exhibit weight loss were 309, 300, 306, 350, 354 and 380 oC for NiPc, CoPc, ZnPc, CrPc, CuPc, and FePc respectively. For electrochemical work in DMF, NiPc was found to be sufficiently soluble whereas CoPc, ZnPc, and FePc were poorly soluble. The low solubility of the metal phthalocyanines limited the scope of experiments of the peripherally substituted phthalocyanines. It could, therefore, be concluded that the metal phthalocyanines prepared in this study showed suitably high thermal stability and can be used for various applications.