Novel fully conjugated 2H- and metal-phthalocyanine network polymers: Synthesis, characterization, and dielectric spectra analysis

摘要

2,7-di-tert-butylpyrene was oxidized to 2,7-di-tert-butylpyrene-4,5,9,10- tetraone. The latter through condensation reactions with vicinal diamine such as 4,5-diaminophthalonitrile produced heterocyclic monomer, 2,7-di-tert-butyl pyrene4,59,10bisquinoxaline-6,7-dinitrile, which was cyclo-tetramerized to the corresponding tetra2,3-(1,4-diaza-6,6-di-tert-butylphenanthreno)4,5 phthalocyanine-based network polymer (2H-Pc), and tetra 2,3-(1,4-diaza-6,6-di- tert-butylphenanthreno)4,5phthalo-cyaninato metal II-based network polymers (M-Pc, M= Co, Ni, Zn, or Cu). Elemental analytical results, IR and NMR spectral data of the new prepared molecules are consistent with their assigned formulations. Molecular masses and metal contents of the synthesized polymers proved to be of high molecular masses which confirm the efficiency of tetramerization polymerization and complexation reactions. The dielectric constant (ε′) and dielectric loss tangent (tan δ) were studied as a function of temperature and frequency. The detailed analysis of the results showed that the dielectric dispersion consists of both dipolar and interfacial polarization. Measurements of ac conductivity as a function of frequency at different temperatures revealed that the nonoverlapping small polaron tunneling is the most suitable mechanism for ac conduction behavior.