Copolymers of 2-methoxyaniline with 2- and 3-aminobenzenesulfonic and 2- and 3-aminobenzoic acids: Relationships between the polymerization conditions, structure, spectroscopic characteristics and conductivity

Mav-Golez, Ida; Pahovnik, David; Bláha, Michal; Žigon, Majda; Vohlı́dal, Jiřı́

doi:10.1016/j.synthmet.2011.06.023

Cited by 13 publications

(4 citation statements)

References 66 publications

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“…(a)) showed a strong B‐band at about 330 nm (contributed by π–π * transitions in benzenoid units) and also a strong Q‐band at 633 nm (contributed by exciton‐like transitions in quinone diimino units). The absorbance ratio of these bands, A B / A Q , which is usually regarded as a measure of the regularity, molar mass and oxidation state of PANIs, was found to be 1.2 for the reference sample A and about 1.4 for the catalytically prepared PANIs (Fig. (b)).…”

Section: Resultsmentioning

confidence: 92%

Self-doping of polyaniline prepared with the FeCl₃/H₂O₂system and the origin of the Raman band of emeraldine salt at around 1375 cm⁻¹

2015

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Section: Resultsmentioning

confidence: 92%

Self-doping of polyaniline prepared with the FeCl₃/H₂O₂system and the origin of the Raman band of emeraldine salt at around 1375 cm⁻¹

2015

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“…The band at 334 nm is connected with π–π* transitions in benzenoid units and the band at 630 nm with exciton-like transitions in quinone diimino units. 32,33 The comparison of intensities of these bands shows that the intensity of the band at 630 nm decreases with the increase of [BzQ]. This is connected with a shift of the maximum of the band belonging to the transitions within benzenoid units from 334 nm to the longer wavelengths.…”

Section: Results and Discussionmentioning

confidence: 93%

Role of p-Benzoquinone in the Synthesis of a Conducting Polymer, Polyaniline

et al. 2019

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Polyaniline (PANI) and 2,5-dianilino- p -benzoquinone both are formed by oxidation of aniline in an acidic aqueous environment. The aim of this study is to understand the impact of addition of p -benzoquinone on the structure of PANI prepared by the oxidation of aniline hydrochloride with ammonium peroxydisulfate and to elucidate the formation of low-molecular-weight byproducts. An increasing yield and size-exclusion chromatography, Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy, and nuclear magnetic resonance analyses of the products show that p -benzoquinone does not act as a terminating agent in the synthesis of PANI and the content of 2,5-dianilino- p -benzoquinone increases with the increasing molar concentration of p -benzoquinone in the reaction mixture, [BzQ]. Regarding the structure of PANI, Raman and UV–visible spectra show that the doping level and the charge delocalization both decrease with the increase of [BzQ], and the FTIR spectra of the PANI bases indicate an increased concentration of benzenoid units at higher [BzQ]. We explain these observations by an increasing concentration of structural defects in PANI chains and propose a 2,5-dianilino- p -benzoquinone-like structure of these defects present as pendant groups. The bands typical of 2,5-dianilino- p -benzoquinone-like moiety are observed even in the vibrational spectra of the sample prepared without addition of p -benzoquinone. This confirms in situ oxidation of aniline to p -benzoquinone within the course of the oxidation of aniline hydrochloride to PANI.

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“…Comparison of UV–visible spectra of the as-prepared PANI S and of the PANI S exposed to 100 and 200 °C reveals the disappearance of the absorption bands at 420 and 840 nm observed in the spectrum of PANI S (Figure A). Both of these bands are connected with polaronic transitions: the band at 420 nm is associated with the polaron → π* transition and the band at 840 nm is assigned to the π → localized polaron transition. ,− The spectrum of PANI S exposed to 200 °C is of comparable character to the spectrum of PANI B (Figure A); it exhibits mainly a broad band with a maximum at 610 nm (exciton-like transition in quinonediimine units ,, ). Exposure of the PANI P to the elevated temperature results in suppression of the bands at 420 and 840 nm as well (Figure B); a new local maximum at about 750 nm is observed in the spectrum of PANI P exposed to 200 °C (Figure B).…”

Section: Resultsmentioning

confidence: 97%

Thermally Induced Protonation of Conducting Polyaniline Film by Dibutyl Phosphite Conversion to Phosphate

2018

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The blue thin polyaniline base film changes its color to green after immersion of the film into dibutyl phosphonate. The green color of the film converts to a greenish-blue after heating to 200 °C in air, which is characteristic for the protonated conducting form of polyaniline. This is in contrast to the "standard" polyaniline hydrochloride, which is transformed into a cross-linked polyaniline base under such conditions. To explain this unexpected observation, the interaction of polyaniline base with dibutyl phosphonate at ambient conditions and after heating to 200 °C was studied using UV−visible, FTIR and Raman spectroscopies. On the basis of these studies, we propose that the dibutyl phosphite tautomeric form of dibutyl phosphonate, which interacts with polyaniline base at 20 °C, converts to the oxidized form, dibutyl phosphate, at 200 °C and subsequently protonates the film. Quantum-chemical modeling of the interaction of polyaniline base with dibutyl phosphite and dibutyl phosphate supports this explanation.

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Copolymers of 2-methoxyaniline with 2- and 3-aminobenzenesulfonic and 2- and 3-aminobenzoic acids: Relationships between the polymerization conditions, structure, spectroscopic characteristics and conductivity

Cited by 13 publications

References 66 publications

Self-doping of polyaniline prepared with the FeCl₃/H₂O₂system and the origin of the Raman band of emeraldine salt at around 1375 cm⁻¹

Self-doping of polyaniline prepared with the FeCl₃/H₂O₂system and the origin of the Raman band of emeraldine salt at around 1375 cm⁻¹

Role of p-Benzoquinone in the Synthesis of a Conducting Polymer, Polyaniline

Thermally Induced Protonation of Conducting Polyaniline Film by Dibutyl Phosphite Conversion to Phosphate

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Copolymers of 2-methoxyaniline with 2- and 3-aminobenzenesulfonic and 2- and 3-aminobenzoic acids: Relationships between the polymerization conditions, structure, spectroscopic characteristics and conductivity

Cited by 13 publications

References 66 publications

Self-doping of polyaniline prepared with the FeCl3/H2O2system and the origin of the Raman band of emeraldine salt at around 1375 cm−1

Self-doping of polyaniline prepared with the FeCl3/H2O2system and the origin of the Raman band of emeraldine salt at around 1375 cm−1

Role of p-Benzoquinone in the Synthesis of a Conducting Polymer, Polyaniline

Thermally Induced Protonation of Conducting Polyaniline Film by Dibutyl Phosphite Conversion to Phosphate

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Self-doping of polyaniline prepared with the FeCl₃/H₂O₂system and the origin of the Raman band of emeraldine salt at around 1375 cm⁻¹

Self-doping of polyaniline prepared with the FeCl₃/H₂O₂system and the origin of the Raman band of emeraldine salt at around 1375 cm⁻¹