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    Electrical and electrochemical properties of double-decker Lu(III) and Eu(III) phthalocyanines with four imidazoles and N-alkylated imidazoles
    (Pergamon-Elsevier Science Ltd, 2012) Yabas, Ebru; Sulu, Mustafa; Dumludag, Fatih; Ozkaya, Ali Riza; Salih, Bekir; Bekaroglu, Ozer
    Imidazole tetrasubstituted double-decker Lu(III) (2) and Eu(III) (3) phthalocyanines have been synthesized by heating 4[(4,5-diphenyl-1H-imidazole)-2-yl-thio]phthalonitrile (1) with Lu(OAc)(3)center dot nH(2)O or Eu(OAc)(3)center dot nH(2)O in n-hexanol in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene, respectively. N-alkylated imidazole tetrasubstituted double-decker Lu(III) (4) and Eu(III) (5) phthalocyanines have been synthesized by the reaction of compounds 2 and 3 with hexyl bromide, in DMF in the presence of K2CO3, respectively. The new compounds were obtained in sufficient purity after successive washing with different solvents and were characterized by elemental analysis and H-1 NMR, UV-Vis, IR, MALDI-TOF mass and electron spin resonance spectra. Electrical measurements of the 2-5 performed in a vacuum (<2 x 10(-3) mbar) in the dark between the temperatures of 295 and 523 K suggest that their films show semi-conductor behavior. It was found that, in general, sigma(d.c.) (4) > sigma(d.c.) (2) in the temperature range 295-458 K, and sigma(d.c). (5) > sigma(d.c.) (3) in the measured temperature range. Depressed semi-circles with different radii at high temperatures in impedance spectra measurements indicated deviation from the Debye dispersion relation. The redox behaviors of the compounds were also investigated by voltammetry and in situ spectroelectrochemistry in dimethylsulfoxide with tetrabutylammonium perchlorate. (c) 2012 Elsevier Ltd. All rights reserved.
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    Imidazole octasubstituted novel mono and double-decker phthalocyanines: Synthesis, characterization, electrical and gas sensing properties
    (Pergamon-Elsevier Science Ltd, 2018) Yabas, Ebru; Sulu, Mustafa; Dumludag, Fatih; Salih, B.; Bekaroglu, Ozer
    Imidazole disubstituted phthalonitrile (1) was prepared by the reaction of 4,5-dichlorophthalonitrile with 4,5-diphenyl-1H-imidazolethiole. Imidazole octasubstituted metal free (2), zinc(II) (3), cobalt(II) (4) monophthalocyanines and lutetium(III) (5) and europium(III) (6) double-decker phthalocyanines were prepared by cyclotetramerization of compound 1. The new compounds were characterized by H-1 NMR, C-13 NMR, UV-vis, IR, MALDI-TOF mass, ESR spectra and elemental analysis. Dc and ac conductivity and gas sensing properties (at room temperature) of the compounds of 2-6 were studied between the temperatures of 295-523 K. Ac conductivity values of the films were measured in the frequency region of 40 Hz-100 kHz. The films were tested for the vapors of toluene, ethanol, THF, n-hexane, chloroform and xylene. DC conductivity results revealed that the compounds 2-6 show a semiconductor behavior. Results of ac measurements show dominant conduction mechanism can be modeled depending on temperature and frequency. The best sensitivity values were obtained for the xylene vapors. The sensor 3 showed best sensitivity among the other sensors for xylene vapor. Response times of the sensors were also determined. (C) 2018 Elsevier Ltd. All rights reserved.
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    Synthesis, characterization and investigation of electrical and electrochemical properties of imidazole substituted phthalocyanines
    (Elsevier Science Sa, 2011) Yabas, Ebru; Sulu, Mustafa; Saydam, Sinan; Dumludag, Fatih; Salih, Bekir; Bekaroglu, Ozer
    Compound 1 has been synthesized by the reaction of 4-nitrophthalonitrile and 4,5-diphenyl-1H-imidazolethiole in DMSO in the presence of K2CO3. Compound 2 has been synthesized by heating compound 1 with metallic lithium in pentanol and hydrolyzed with hydrochloric acid (10%) and then neutralized with ammonia solution. Compound 3 and 4 have been synthesized by heating 1 with ZnCl2 or CoCl2 in DMF in the presence of 1,8-diazabicyclo[5.4.0] undec-7-ene (DBU), respectively. The new compounds were obtained in sufficient purity after successive washing with different solvents and were characterized by elemental analysis, H-1 NMR, C-13 NMR, UV-vis, IR and mass spectra. We also studied aggregation behavior, electrochemical and electrical properties of these phthalocyanines. Direct current (dc) and alternating current (ac) conductivity (40-100 kHz) measurements of films of 2, 3 and 4 were performed in the temperature range of 295-523 K. Impedance spectra (IS) of the 2, 3 and 4 were also studied. The conduction processes were discussed. Temperature dependence of dc conductivity of the films revealed that 2, 3 and 4 show a semiconductor behavior. Results of ac measurements showed that, conduction processes of the films of the complex consisted of different mechanisms depending on temperature and frequency. (C) 2010 Elsevier B.V. All rights reserved.