Polyarylenealkenylenes and Polyheteroarylenealkenylenes XVIII. Polycondensation of 5-Methylfuran-2-carbaldehyde— An Easy Route to Electrically Conductive Materials (original) (raw)
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Electrogeneration of conducting poly(2,5-di-(-2-thienyl)-furan)
Journal of Electroanalytical Chemistry, 1998
The electrochemical behaviour of 2,5-di-(-2-thienyl)-furan (SOS) on Pt has been studied in 0.2 M LiClO 4 + acetonitrile+0.25% (v/v) water solutions by cyclic voltammetry, chronoamperometry and chronopotentiometry. The monomer oxidises at more positive potentials than 0.7 V vs. AgAgCl giving a dark-blue film. The most reproducible film weights are obtained by flowing a constant current lower than 1.0 mA cm − 2. The resulting insoluble oxidised films are electroactive and electrochromic. Their control voltammograms exhibit two redox processes attributed to polaronic and bipolaronic states, together with an intermediate reduction shoulder ascribed to radical cation pairs. Electropolymerisation kinetics have been followed by 'ex situ' ultramicrogravimetry, giving a maximum productivity of 1.85 mg mC − 1. The oxidised poly(SOS) contains polarons and electroinactive positive charges, both compensated with perchlorate counterions. The reduced poly(SOS) has been obtained in the same electrolyte by applying a constant potential of 0 V to oxidised films. A partial electrodissolution of films is observed during their reduction. The electroinactive charges present in the resulting reduced state cause its insolubility in the medium. Densities, conductivities and solubilities in different organic solvents of both oxidised and reduced poly(SOS) have been determined. Short linear oligomers formed during SOS electropolymerisation have been detected in the saturated solutions of reduced poly(SOS) by mass spectrometry-fast atom bombardment.
A Novel Poly{(2,5-diyl furan) (benzylidene)}: A New Synthetic Approach and Electronic Properties
ISRN Physical Chemistry, 2012
A new conjugated aromatic poly[(furan-2, 5-diyl)-co-(benzylidene)] has been prepared by polycondensation of benzaldehyde and furan catalyzed by Maghnite-H + . Maghnite-H + is a montmorillonite sheet silicate clay, which exchanged with protons. These polymers can be dissolved in high polar solvents such as DMSO, DMF, THF, or CHCl 3 A kind of band-gap conjugated poly[(furan-2, 5-diyl)-co-(benzylidene)] has been synthesized by a simple method and characterized by 1 HNMR, 13 CNMR, FT-IR, and UV-Vis. The result reveals that the band-gap of the PFB conjugated polymer has an optical band gap of 2.2 eV.
Soluble conducting polymers: The poly(3-alkylthienylenes)
Synthetic Metals, 1987
The conjugated poly(3-alkylthienylenes) can be processed from solution and subsequently used as semiconducting and metallic polymers. Both assynthesized and solution-cast films can be readily doped to give electrical conductivities that are quite high: a ~ 30 -100 S/cm. Ultraviolet-visible absorption spectra of the neutral and doped forms have been obtained for solid films (as-synthesized and solution-cast) and for the polymers in solution. Excitation into the ~-~* transition (peak at ~ 2.8 eV), leads to photoluminescence (peak at 2.16 eV). The Stokes' shift is consistent with radiative decay from photogenerated neutral bipolarons (exciton-polarons). From electron spin resonance measurements and spectroscopic data on the doped polymer in solution, we have determined the nature of the charge storage configurations. The results indicate that the spinless bipolaron is the lowest energy charge storage configuration on single poly(3-hexylthienylene) macromolecules in solution. Polarons are formed either as a result of an odd number of charges on a single polymer chain or as a result of interchain interactions (in the semi-dilute regime).
Journal of Chemical Education, 2014
Poly(phenylene vinylene) (PPV) represents an important class of conjugated, conducting polymers that have been readily exploited in the preparation of organic electronic materials. In this experiment, students prepare a PPV polymer via a facile multistep synthetic sequence with robust spectroscopic evaluation of synthetic intermediates and the final product. The synthetic sequence could be applied by university instructors as a capstone project for an undergraduate organic chemistry laboratory or as a centerpiece project for either a polymer or integrated laboratory course. The initial synthetic step could be segmented and used as a modular piece in the traditional introductory organic chemistry laboratory. In either case, the resultant PPV polymer is analyzed by UV−vis and fluorescence spectroscopy to determine the quantum yield which promotes enhanced student understanding of the photophysical properties of the material. In addition, GPC analysis is completed to reveal the molecular weight and polydispersity of the polymer. Students completing this experiment gain valuable experience in organic/polymer synthesis and structural characterization utilizing GC/MS, GPC, NMR, UV−vis, and fluorescence spectroscopy, as well as in the mechanistic aspects and practical application of some of the classic transformations in organic chemistry including the S N 2 reaction, nucleophilic acyl substitution, organometallic chemistry, and Wittig reaction.
Recent studies of heterocyclic and aromatic conducting polymers
Progress in Polymer Science, 1986
CONTENTS 1. Introduction 2. Polymerization and doping 2.1. Mechanism of conducting polymerization 3. Characterization of conducting polyheterocyclics and polyaromatics 3.1. Stability of polyheterocyclics and polyaromatics 3.2. Percentage of doping, molecular weight, mechanical properties and morphology of conducting polyheterocyclics and polyaromatics 3.3. Spectroscopy of heterocyclic and aromatic conducting polymers 3.3.1. Electrochemical spectroscopy of conducting polyheterocyclics and polyaromatics 3.3.2. Optical and ESR studies 3.3.3. t3C NMR and XPS studies 201 4. Mechanism of electrical conduction in doped polyheterocyclics and polyaromatics 202 5. Conducting copolymers 206 6. Application of doped polyheterocyclics and polyaromatics 208 6.1. Battery application 208 6.2. Photo-electrochemical cell (PEC) 6.3. Schottky barriers, solar cells and solid-state devices 210 6.4. Electro-optic devices 211 6.5. Sensors 6.6. Medicinal uses 213 6.7. Miscellaneous applications 214 7. Concluding remarks Acknowledgements 214 References
Synthesis and electroconductivity of poly(1,4-phenylene-1,3,5-hexatrienylene-1,4-phenylenevinylene)
Synthetic Metals, 1989
A new polyconjugated polymer, poly(l,4-phenylene-l,3,5-hexatrienylene-l,4phenylenevinylene) was synthesized via the sulfonium salt process. The polymer obtained in powder form could be doped with 12 and exhibited a maximum conductivity of about ixl0-3 Scm-I. Compared with poly(l,4-phenylenevinylene), the presence of the longer hexatrienylene unit along the backbone improves dopability with 12 and, therefore, the electrical conductivity. The same polymer, when doped with H2SO4, exhibited a maximum conductivity of about 2x10-I Scm-I .
Journal of Research Updates in Polymer Science, 2014
A new interesting class of conducting polymers based on methyl-cyclohexanone in the polymer main chain has been synthesized by solution polycondensation of terephthalaldehyde with methyl-cyclohexanone. Copolymers containing different cycloalkanone moieties were also synthesized using solution polycondensation technique. The model compound I was synthesized by the interaction of methyl-cyclohexanone monomer with benzaldehyde, and its structure was confirmed by elemental and spectral analyses. The resulting new polymers and copolymers were characterized by elemental and spectral analyses, beside solubility and viscometry measurements. The thermal properties of those polymer and copolymers were evaluated by TGA, DrTGA and DTA measurements and correlated to their structural units. PDT as well as T10 was in the range from 205 to 370 ºC. In addition, T10 thermal stability for all the polymers was in the order: VI> II > III > IV > V. X-ray analysis showed that it has some degree of crystallinity in the region 2 = 5-60 degree.The UV-visible spectra of some selected polymers were measured in DMSO solution and showed absorption bands in the range 265-397 nm, due to n-* and-* transition. The morphological properties of copolymer IV as selected examples were tested by SEM. The electrical conductivities of the synthesized polymers and copolymers enhanced to become in the range of 10-9-10-8 S cm-1 by doping with iodine.
Chemistry & Chemical Technology
Poly(o-toluidine) doped with acrylic acid and without it was synthesized by using chemical oxidative polymerization technique. With the help of this method the polymer, poly(o-toluidine) was synthesized in the form of emeraldine salt. The oxidizing agent used for this method is the ammonium persulphate .The polymer products were characterized by UV-Visible and FTIR spectroscopy. The polymer, poly(o-toluidine) doped with acrylic acid was highly soluble in common organic solvents like m-cresol, NMP, DMF etc. The FTIR studies demonstrate that the acrylic acid doped poly(o-toluidine) shows broad and intense band at 3250-3000 cm -1 and 1160-1100 cm -1 account for the higher degree of doping. These results are well supported by conductivity measurements.
Materials Chemistry and Physics, 1999
The state of the art of novel electronically conducting polymeric materials is presented in this review. The special emphasis is laid on the electrochemical synthesis of conducting polymers (CPs) including the choice of the monomers and solvents, supporting electrolytes and electrodes and structural aspects of these novel materials and the nature of the dopants which induce electrical conductivity in conjugated organic polymers. Finally, an overview of various technological applications of these novel polymeric materials to electronics, optoelectronics devices like electrochromic cells, light emitting electrochemical cells and photoconducting devices, solar cells such as photovoltaic and photoelectrochemical (PEC) cells, p-n-semiconductors, metal-insulator-semiconductors (MIS), laser materials and energy storage applications like solid-state rechargeable batteries and supercapacitors has been presented.