Mixed ionic and electronic conductivity study of charge transfer complexes of some substituted pyridines with iodine monochloride (ICl) by AC impedance spectroscopy

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• 作者：Uttam Mohan ; Pallavi Gogoi ; S. K. Baruah
• 关键词：CT complex ; Mixed conduction ; Impedance spectra ; Transport number
• 刊名：Ionics
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：23
• 期：1
• 页码：157-168
• 全文大小：
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Electrochemistry; Renewable and Green Energy; Optical and Electronic Materials; Condensed Matter Physics; Energy Storage;
• 出版者：Springer Berlin Heidelberg
• ISSN：1862-0760
• 卷排序：23

文摘

Mixed ionic and electronic conductivity of three solid charge transfer (CT) complexes of pyridine, 4-methylpyridine (γ-picoline) and 3,5-dimethylpyridine (3,5-lutidine) with ICl (iodine monochloride) are reported. Electrical parameters of the prepared complexes in the pellet form are evaluated at various temperatures and at wide frequency range by employing AC complex impedance spectroscopic technique. Suitable equivalent circuits for the Nyquist plots, which provide the most realistic model of the electrical properties of the CT complexes, have been suggested. Both transport number measurements and impedance spectra reveal that the conduction in γ-picoline-ICl complex is mainly due to ions, in 3,5-dimethylpyridine-ICl complex, it is due to both ions and electrons and in pyridine-ICl complex, it is predominantly due to electrons. The a.c. conductivity measurements of the CT complexes have been carried out in the frequency range of 10–105 Hz within the temperature range of 303–353 K. The variation of a.c. conductivity with frequency follows the Jonscher’s universal power law. The temperature dependence of electrical conductivity suggests the semiconducting behaviour of the materials.