Ersen Turac

Synthesis and characterization of poly{2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole} and its copolymer with EDOT

A pyrrole-functionalized monomer 2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole (PyPhPy) was synthesized. The structure of monomer was investigated by Nuclear Magnetic Resonance (1H NMR) and Fourier Transform Infrared (FTIR) spectroscopy. The chemical polymerization of PyPhPy (CPyPhPy) was realized using FeCl3 as the oxidant. The electrochemical oxidative polymerization of polymer P(PyPhPy) and its copolymer with 3,4-ethylenedioxythiophene poly(2-[3-(1H-pyrrol-2-yl)phenyl]-1H-pyrrole-co-3,4-ethylenedioxythiophene) [P(PyPhPy-co-EDOT)] were achieved via potentiodynamic method by using NaClO4/LiClO4 as the supporting electrolyte in CH3CN. Characterizations of the resulting polymers were performed by cyclic voltammetry (CV), FTIR, scanning electron microscopy (SEM), UV-Visible spectrophotometry (UV-Vis) and thermogravimetry analyses (TGA). Electrical conductivity of CPyPhPy, P(PyPhPy), and P(PyPhPyco-EDOT) were measured by four-probe technique.

Electrochemical Synthesis of a Water-Soluble and Self-Doped Polythiophene Derivative

A new monomer, 4-(thiophen-3-yl methyleneamino)benzene sulfonate) (ThSA), was synthesized and characterized. Electrochemical polymerization of ThSA yields a water-soluble and self-doped polymer (PThSA). This polymer was characterized by FT-IR, NMR, DSC, XRD and conductivity measurements.

Synthesis, Characterization and Optoelectrochemical Properties of Poly(2,5-di(thiophen-2-yl-)1-(4-(thiophen-3-yl)phenyl)-1H-pyrrole-co-EDOT)

A new polythiophene derivative was synthesized by electrochemical oxidative polymerization of 2,5-di(thiophen-2-yl)-1-(4-(thiophen-3-yl)phenyl)-1H-pyrrole (TTPP). The structure of the monomer was evaluated by 1H-NMR and FT-IR. The polymer (P(TTPP)) and its co-polymer with 3,4-ethylenedioxythiophene (P(TTPP-co-EDOT)) were synthesized via potentiostatic electrochemical polymerization. The resulting polymers were characterized by cyclic voltammetry (CV), FT-IR, SEM and UV-Vis spectroscopy, and conductivity measurements. Also, the spectroelectrochemical and electrochromic properties of P(TTPP-co-EDOT) were investigated. While P(TTPP) reveals no electrochromic activity, its co-polymer with EDOT has two different colours (yellow and blue). Optical contrast, switching time, λ max and band gap (E g) of (P(TTPP-co-EDOT)) were determined.

A FACILE SYNTHESIS OF HETEROTRICYCLES FROM FURFURYLBROMOALKENES USING THERMAL IMDA CYCLO ADDITION

A variety of key precursors to the IMDA reaction of furan diene have been prepared via facile alkylation. Subsequently, rigid tricyclic compounds (2a-g) possessing oxygen, nitrogen, and sulfur has been synthesized by employing thermal intramolecular Diels-Alder reactions. These heterocyclic fused tricycles include a bromo quaternary carbon centre obtained stereoselectively with moderate yields (32-44 % overall).

Synthesis and Characterization of Conducting Copolymers of Thiophene Derivatives

Electrochemical copolymerizations of N1,N2-bis(thiophen-3-ylmethylene)benzene-1,2-diamine (TMBD), 4-methyl-N1,N2-bis (thiophen-3-ylmethylene)benzene-1,2-diamine (MTMBD) and 4-nitro-N1,N2-bis(thiophen-3-ylmethylene)benzene-1,2-diamine (NTMBD) with 3,4-ethylenedioxy thiophene (EDOT) were carried out in CH3CN/LiClO4 (0.1 M) solvent–electrolyte couple via potentiodynamic electrolysis. The resulting copolymers were characterized by cyclic voltammetry (CV), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The conductivity measurements of copolymers and PEDOT were carried out by the four-probe technique.

Chemoenzymatic polycondensation of para-benzylamino phenol

Abstractpara-Benzylamine substituted oligophenol was synthesized via enzymatic oxidative polycondensation of 4-(benzylamino)phenol (BAP). Polymerization involved only the phenolic moiety without oxidizing the sec-amine (benzylamine) group. Chemoselective polycondensation of BAP monomer using HRP enzyme yielded oligophenol with sec-amine functionality on the side-chain. Effects of various factors including solvent system, reaction pH and temperature on the polycondensation were studied. Optimum polymerization process with the highest yield (63 %) and molecular weight (Mn = 5000, degree of polymerization ≈ 25) was achieved using the EtOH/ buffer (pH 5.0; 1: 1 vol. ratio) at 25°C in 24 h under air. Characterization of the oligomer was accomplished by 1H NMR and 13C NMR, Fourier transform infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), ultraviolet-visible spectroscopy (UV-Vis), cyclic voltammetry (CV) and thermogravimetric analysis (TGA). The polymerization process involved the elimination of hydrogen from BAP, and phenolic-OH end groups of the oligo(BAP), confirmed using 1H NMR and FT-IR analyses. The oligomer backbone possessed phenylene and oxyphenylene repeat units, and the resulting oligomer was highly soluble in common organic solvents such as acetone, CHCl3, 1,4-dioxane, N,N-dimethylformamide (DMF), tetrahydrofurane (THF) and dimethylsulfoxide (DMSO). Oligo(BAP) was thermally stable and exhibited 5 % and 50 % mass loss determined by thermogravimetric analysis at 247°C and 852°C, respectively.

Synthesis and characterization of conducting copolymer of (N1,N3-bis(thiophene-3-ylmethylene)benzene-1,3-diamine-co-3,4-ethylenedioxythiophene)

Electrochemical copolymerization of N1,N3-bis(thiophene-3-ylmethylene)benzene-1,3-diamine (TMBA) with 3,4-ethylenedioxythiophene (EDOT) was carried out in a CH3CN/LiClO4 (0.1 M) solvent-electrolyte via potentiodynamic electrolysis. Chemical structure of the monomer was determined by nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectroscopy. The resulting copolymer was characterized by cyclic voltammetry (CV), FTIR, scanning electron microscopy (SEM), and thermogravimetry analyses (TGA). Conductivity measurements of the copolymer and PEDOT (poly(3,4-ethylenedioxythiophene)) were carried out by the four-probe technique.

Chemoenzymatic polymerization of hydrazone functionalized phenol

Hydrazone substituted oligophenol was synthesized via enzymatic oxidative polymerization of (E)-2-((2-phenylhydrazono)methyl)phenol. Enzymatic polymerization catalyzed by Horseradish peroxidase (HRP) enzyme and H2O2 oxidizer yielded oligophenol with hydrazone functionality on the side-chain. Effects of various factors including solvent system, reaction pH and temperature on the polymerization were studied. Optimum polymerization conditions with the highest yield (84%) and molecular weight (M n = 8 × 103, DP ≈ 37, PDI = 1.11) was achieved using MeOH/pH 6.0 buffer (1: 1 vol %) at 25°C in 24 h under air. Synthesized oligomer was characterized by 1H and 13C NMR, FTIR, UV–Vis spectroscopy, GPC, cyclic voltammetry and thermogravimetric analyses. The polymerization involved hydrogen elimination from the monomer, and terminal units of the oligomer structure consisted of phenolic hydroxyl (–OH) end groups. The oligomer backbone possessed phenylene and oxyphenylene repeat units. The resulting oligomer was completely soluble in common organic solvents. The oligomer was thermally robust and exhibited 5% mass loss at 375°C and 50% mass loss at 440°C.