Preparation and Optoelectronic Properties of Electropolymerized Films from N-Phenylcarbazole Dendrons

• Main Authors: Shu-Wei Lin, 林書緯
• Other Authors: Sheng-Huei Hsiao
• Format: Others
• Language: en_US
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/p3up2v

碩士 === 國立臺北科技大學 === 化學工程研究所 === 103 === In the first part of this thesis, two compounds with tri-carbazole (3Cz) structure were synthesized, namely 3,6-di(carbazol-9-yl)-N-(4-nitrophenyl)carbazole [NO2-3Cz] and 3,6-di(carbazol-9-yl)-N-(4-aminophenyl)carbazole [NH2-3Cz]. These 3Cz-derivatives can be electropolymerized into polymer films on the electrode surface in an electrolyte solution via the carbazole-carbazole and NH2-carbazole coupling reactions. These electro-generated polymer films exhibited reversible electrochemical oxidation processes, with a significant electrochromic behavior. The color of P(NO2-3Cz) film changed from pale yellow neutral state to yellow-green as a radical cation and then to blue when fully oxidized. Upon oxidation, the color of P(NH2-3Cz) film changed from colorless to pale green and finally to blue. Furthermore, we also synthesized and characterized some N-phenylcarbazoles with different substituents on the phenyl group. Based on a comparative study, the possible electropolymerization mechanisms of the NO2-3Cz and NH2-3Cz monomers are suggested. In the second part of this thesis, two series of novel diamide- or diimide-cored N-phenylcarbazole dendrons were synthesized from condensation reactions of 3,6-di(carbazol-9-yl)-N-(4-aminophenyl)carbazole (NH2-3Cz) with aromatic dicarboxylic acids and tetracarboxylic dianhydrides, respectively. These dendrons can be electropolymerized into crosslinked poly(amide-carbazole) and poly(imide-carbazole) films on the electrode surface in an electrolyte solution via the coupling reactions between carbazole radical cations. Cyclic voltammograms of the polymer films showed two reversible oxidation redox couples accompanied with color change from the colorless neutral state to the yellow-green and blue oxidized forms. The electrochromic behavior of the film is clearly interpreted on the basis of spectroelectrochemical studies. Single layer electrochromic cells were also fabricated as preliminary evaluation for their application as electrochromic devices.