Synthesis, Characterization, and Evaluation of Electrochemical and Thermal Properties of New Cobalt Phthalocyanine(Copc) using Phthalamide as Precursor

Aminu Dauda1*, Abdul Ademola Olaleye1, Sinan Saydam2 and M.N.Yaro1

1Department of Chemistry, Faculty of Science, Federal University Dutse, P.M.B. 7156, Jigawa State, Nigeria 2Department of Chemistry, Faculty of Science, Firat University Elazig, Turkey

*Corresponding author:


Cobalt phthalocyanine was synthesized from 3-nitrophthalonitrile using phthalamide as a precursor. Nitration in position 3 of the phthalamide led to the formation of 3-nitrophthalamide; then dehydration bythionyl chloride in N, N-dimethylformamide led to the formation of 3- nitrophthalonitrile. Phthalonitrile derivative was prepared by a nucleophilic substitution reaction of 3 nitrophthalonitrile in the presence of K2CO3 as a base in a non aqueous organic solvent. Cyclotetramerization of phthalonitrilein in the presence of metal acetate, (Co(Ac)2.4H2O) gave peripherally substituted metal phthalocyanine complexes. The structure of the synthesized compounds was characterized by different analytical tools such as UV-Vis, FT-IR spectrophotometry and cyclic voltammetry The disappearance of the C≡N stretching vibration from the IR spectra of phthalonitrile wasobserved at 2230 cm−1. The FT-IR vibration results for cobalt phthalocyanine was found to be 1709cm-1, 1611 cm-1 and 1275 cm-1 for C=O, C=C and C-O respectively. Solubility of metal phthalocyanine complexes was found to be very low in common laboratory solvents such as tetrahydrofuran (THF) and dimethylformamide (DMF). The electronic spectrum of CoPc in dimethylformamide (DMF) showed intense Q absorption at 677 nm. UV-Vis spectra of phthalocyanines showed electronic spectra with two strong absorption bands, Q and B bands. The Q band was found in 600–750 nm and B at 300 400 nm for both. The thermal stability of the phthalocyanine derivative was checked by T.G.A and the degradation was observed to start at 300oC, which showed that the complex could withstand fairly high temperature. It could therefore be concluded that the metal phthalocyanine prepared in this study showed fairly high thermal stability and can be used for various applications such as dye.

Keyword: Phthalamide, cobalt phthalocyanine, electrochemistry, 3-nitrophthalonitrile