The synthesis and characterization of new stilbene bridged polymeric zinc(II) phthalocyanine

In the present work, we synthesized a new polymeric phthalocyanine which containing zinc(II) and its precursor namely diethylstilbesterol diphthalonitrile ether. Diethylstilbesterol diphthalonitrile ether was synthesized by nucleophilic aromatic substitution of diethylstilbesterol onto 4-nitrophthalonitrile. Polymeric zinc phthalocyanine was synthesized by polymeric cyclotetramerization of tetranitrile monomer and Zn(CH3COO)2.2H2O. The structures of the novel compounds were confirmed by elemental analysis together with FT-IR, 1H-NMR, 13C-NMR, UV-Vis and MS spectroscopic techniques. To understand the semiconducting and dielectric properties of polymeric zinc phthalocyanine, a systematic investigation on dc and ac electrical properties and their variation with temperature and frequency was attempted. Dc and ac conduction properties of polymeric zinc phthalocyanine pellet was investigated in the frequency range of 100 to 1.6×106 Hz and temperature 300–505 K. σdc was found to follow a variable range hopping (VRH) mechanisms up to ~ 400 K. Above this temperature σdc follows thermally activated conduction mechanism only. Based on the existing theories of ac conduction, it was concluded that the temperature dependence of the exponent s and conductivity, the correlated barrier hopping (CBH) model is the dominant conduction mechanism for electron transport in the polymeric zinc phthalocyanine pellet. Also, thermal properties of the polymeric zinc phthalocyanine were investigated by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA).