Synthesis, characterization and electrical and CO2 sensing properties of triazine containing three dendritic phthalocyanine

• Published in: Synthetic metals 2005-10, Vol.155 (1), p.211-221
• Main Authors: SÜLÜ, Mustafa, ALTINDAL, Ahmet, BEKAROGLU, Özer
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Inorganic and organomineral polymers; Physicochemistry of polymers; Preparation
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2005.08.005

The metal-free phthalocyanine 1a was synthesised by statistically mixed condensation of 4-nitrophthalonitrile and 4-(2-dimethylaminoethylsulfanyl)phthalonitrile in dry 2-(dimethylamino)ethanol. The same route were applied to prepare metal-containing phthalocyanines using metal salts Zn(OAc)3DDT2H2O and CoCl2, respectively, in dry DMF. . . . The new compounds were characterized by elemental analysis and UV-vis, IR, NMR spectra. The temperature dependence of the dc and ac conductivity of these compounds and the adsorption of CO2 gas on thin film of the compounds were investigated by dc conductivity and impedance spectroscopy technique using an interdigital transducer structure on glass substrate. While exposure to CO2 have no influence on the electrical conductivity (ac and dc) of compound 6a and 6c, the conductivity of the film of 6b strongly depend on the presence of the CO2 gas. Completely reversible sensor signals were obtained for compound 6b. The impedance spectra were obtained at frequencies between 40 and 105Hz, and in a wide range of CO2 concentrations (from 500 to 8000ppm) at room temperature. The temperature dependence of dc conductivity show typical Arrehenius behaviour for all compounds. The ac conductivity of the films is represented by the form D*ws. The dependency of frequency exponent s on temperature suggests a correlated barrier hopping (CBH).