ELECTROCHEMICAL COPOLYMERIZATION OF N-METHYL PYRROLE WITH CARBAZOLE (original) (raw)
Related papers
The copolymerization of N-Methylpyrrole (N-MPy) and N-ethylcarbazole (ECz) by chemical and electrochemical methods is investigated in detail. Random copolymers of poly[N-Methylpyrrole-N-ethylcarbazole], P[N-MPy-co-ECz], were synthesized in the presence of ceric ammonium nitrate (CAN) in acetonitrile. Electrocopolymerization of N-MPy, and ECz was carried out in various solvents on platinum electrode. Propylene carbonate (PC) was found to be the most suitable solvent for film formation. The effects of sweep rate, supporting electrolyte type, mole ratio, and temperature on the electropolymerization were discussed. The electrochemical properties of Poly(N-ethylcarbazole), (PECz) were improved on copolymerizing it with N-MPy. A copolymerization mechanism has been suggested. The resulting copolymer was characterized by UV-Vis and FT-IR spectroscopic methods, as well as cyclic voltammetric measurements.
The copolymerization of N-Methylpyrrole (N-MPy) and N-ethylcarbazole (ECz) by chemical and electrochemical methods is investigated in detail. Random copolymers of poly[N-Methylpyrrole-N-ethylcarbazole], P[N-MPy-co-ECz], were synthesized in the presence of ceric ammonium nitrate (CAN) in acetonitrile. Electrocopolymerization of N-MPy, and ECz was carried out in various solvents on platinum electrode. Propylene carbonate (PC) was found to be the most suitable solvent for film formation. The effects of sweep rate, supporting electrolyte type, mole ratio, and temperature on the electropolymerization were discussed. The electrochemical properties of Poly(N-ethylcarbazole), (PECz) were improved on copolymerizing it with N-MPy. A copolymerization mechanism has been suggested. The resulting copolymer was characterized by UV-Vis and FT-IR spectroscopic methods, as well as cyclic voltammetric measurements. Ã Given potentials have deviation ¼ AE0.003 V. 1 Polymer oxidation potential, V. 2 Monomer oxidation potential, V. a Initial feed ratio of monomers, n N-MPy =n ECz ¼ 2.
2011
C opolymerizations of pyrrole (Py) with N-pentylpyrrole (NPPy) and N-dodecylpyrrole (NDPy) were carried out by chemical and electrochemical oxidation methods. Nanoparticles made of conjugate copolymers with different feed ratios of monomers were prepared by chemical polymerization (conventional and interfacial methods) in presence of iron (III) chloride hexahydrate (FeCl 3 .6H 2 O) as the oxidant. Nanostructure copolymers with higher conductivity were synthesized by simply tuning the preparation conditions in a two-phase medium (toluene-water as solvents). The Npentylpyrrole and N-dodecylpyrrole monomers were synthesized with higher purity from pyrrole. Fourier transform infrared spectroscopy, scanning electron microscopy and four probe conductivity measurement techniques were applied for the characterization of the copolymers. The conductivity of the copolymers obtained by interfacial method using toluene as an organic phase was 5-6 times higher than the copolymer obtained by a conventional method (for molar ratio of Py:NPPy, 30:70). In electrochemical method, copolymer thin films were synthesized with different feed ratios of monomers by cyclic voltammetry in lithium perchlorate-acetonitrile (LiClO 4 /CH 3 CN) electrolyte on the surface of the glassy carbon (GC) as the working electrode. Deposition conditions on the GC, influence of the molar ratio of monomers on the electroactivity and formation of copolymers were studied using cyclic voltammetry.
Oxidative electropolymerizations of carbazole derivatives in the presence of bithiophene
Synthetic Metals, 2004
N-Ethylcarbazole (NECZ) or carbazole (CZ) and bithiophene (BT) have been used as a mixture of monomers for the formation of electrodeposited polymer and copolymer films on platinum electrode. When beginning with a NECZ-BT mixture, the peak intensity resulting from the composite film cycling decreases with increasing initial NECZ proportion until that proportion reaches 40%. For higher NECZ proportions, no deposit could be obtained. Infrared spectra of the deposits show the presence of the characteristic bands of both monomer units in the material. In the case of CZ-BT mixtures, the electrochemical behaviours of the composite films are close to those displayed by the homopolymers, i.e. polybithiophene or dicarbazyle, containing respectively low and high proportions of CZ. Furthermore, infrared and ultraviolet-visible studies of deposits obtained for various CZ proportions yield spectra that vary according to monomer proportion.
In this work, 9-(2-(benzyloxy)ethyl)-9H-carbazole (BzOCz) and 1-tosyl-1H-pyrrole (TsP) monomers were chemically synthesized and characterized by Fourier transform infrared reflectance (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. BzOCz and TsP were electrocoated on glassy carbon electrode (GCE) in various molar fractions (XTsP00.5, 0.83, 0.91, and 0.98) in 0.1 M sodium perchlorate/acetonitrile. The detailed characterization of poly (BzOCz-co-TsP) was studied by cyclic voltammetry, FTIRattenuated total reflection spectroscopy and electrochemical impedance spectroscopy (EIS). The effects of different molar fractions during the preparation of modified electrodes were studied by EIS technique. The AC impedance technique was used to determine the capacitive behaviors of modified GCE via Nyquist, Bode magnitude, and Bode phase plots. The highest low frequency capacitance value was obtained as CLF023.94 μF cm−2 for XTsP00.98. Therefore, synthesized copolymer has more capacitive behavior than its homopolymers, such as CLF07.5 μF cm−2 for poly(BzOCz) and CLF0 9.44 μF cm−2 for poly(TsP). In order to interpret the AC impedance spectra, R(Q(RW)) electrical equivalent circuit was employed with linearKramers–Kronig test. A mechanism for electropolymerization has been proposed for copolymer formation.
Journal of Solid State Electrochemistry, 2013
Conducting poly(pyrrole-N-methylpyrrole) (P(Py-NMPy)) was electrochemically synthesized on a gold electrode in a lithium perchlorate-containing acetonitrile electrolyte solution and compared with polypyrrole (PPy) and poly(N-methylpyrrole) (PNMPy) prepared under the same conditions. The obtained polymers were characterized with cyclic voltammetry, in situ resistance measurements, in situ UV-vis spectroscopy, FTIR spectroscopy, and scanning electron microscopy. The onset potentials for pyrrole and N-methylpyrrole monomer oxidation differ by about 0.1 V. Nucleation processes initiated by the radical cations are followed by growth of nuclei into continuous films. The oxidation and reduction peaks for the P(Py-NMPy) copolymer synthesized at 1:1 M concentration ratio of the comonomers are between those of PPy and PNMPy. A decreased [Py]/[NMPy] comonomer concentration ratio yields in the copolymers shifts of peak potentials to more positive values. The in situ resistance of copolymers measured from −0.20 to 0.90 V vs. Ag/AgCl decreased with increasing [Py]/[NMPy] concentration ratio. In situ UV-vis and ex situ FTIR spectra of copolymers show spectroscopic behavior intermediate between those of the homopolymers. Scanning electron microscopy micrographs of the samples show fundamental differences between the morphology of the homo-and copolymers.
Poly (pyrrol-co-o-aminobenzoic acid) has been synthesized electrochemically from an aqueous acid medium. The initial rate of electrocopolymerization reaction on platinum electrode is small and the rate law is: Rate 5 K2 [D]1.02[HCl] 1.44[M]2.00. The apparent activation energy (Ea) is found to be 90.11 kJ mol21. The polymer films obtained have been characterized by cyclic voltammetry, X-ray diffraction, elemental analysis, thermogravimetric analysis, scanning electron microscopy, 1H NMR, and IR-spectroscopy. The mechanism of the electrochemical polymerization reaction has been discussed. The monomer reactivity ratios (r1 and r2) were calculated.
Applied Surface Science, 2015
A direct electrochemical copolymerization of pyrrole-formyl pyrrole (Py-co-FPy) was carried out by oxidative copolymerization of formyl pyrrole and pyrrole in LiClO 4 aqueous solution through galvanostatic method. The (Py-co-FPy) copolymer was characterized using Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FESEM), energy-filtering transmission electron microscope (EFTEM), thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The FESEM images showed that the synthesized copolymer had a hollow whelk-like helixes structure, which justifies the enhancement of charge transportation through the copolymer film. Cyclic voltammetry studies revealed that the electrocatalytic activity of synthesized copolymer has improved and the surface coverage in copolymer enhanced 1.6 times compared to polypyrrole alone. Besides, (Py-co-FPy) copolymer showed 2.5 times lower electrochemical charge transfer resistance (R ct) value in impedance spectroscopy. Therefore, this copolymer has a strong potential to be used in several applications such as sensor applications.