Design and synthesis of novel donor-acceptor type monomers and ınvestigation of optoelectronic properties of their polymers

Ünver, Elif Köse
A proven strategy, donor-acceptor approach, to reduce the band gap of conjugated materials and possibly improve the photocurrent is to incorporate electron-rich and electron-deficient units in an alternating fashion in a polymer chain. For this purpose, a wise selection of donor and acceptor moieties in a monomer structure results in desired finishing properties of polymeric materials. In this study, fourteen novel monomers were synthesized to explore the acceptor and donor effects on the electronic and optoelectronic properties. Dibenzophenazine, dibenzopyrido]quinoxaline, tetrahydro- dibenzophenazine, thiadiazoloquinoxaline, pyrazinoquinoxaline, thienopyrazine, benzoselenadiazole, thienoselenadiazole were used as acceptor moieties, while thiophene, 3-hexylthiophene and 2,3-dihydrothienodioxine (EDOT) were used as the donor components in these donor-acceptor molecules. To synthesize desired monomers, well-known synthetic methods were performed, including bromination, nitration, reduction and condensation. Bromination was achieved by two different ways depends on the aim, NBS and Br2/HBr medium. For the nitration, HNO2 and H2SO4 were used together. Fe metal in refluxing acetic acid was used as the reducing agent in case of nitro group reductions. On the other hand, Zn metal/AcOH system was chosen for the reduction of both nitro groups and thiadiazole structure to amine, simultaneously. Finally, the Stille Coupling was used to obtain resulting acceptor-donor-acceptor monomers. These synthesized monomers were polymerized by electrochemically and investigated their properties by methods such as spectroelectrochemistry, kinetic and colorimetry studies. Spectroelectrochemistry experiments were performed in order to investigate key properties of conducting polymers such as band gap, maximum absorption wavelength, the intergap states that upon doping and evolution of polaron and bipolaron bands. Switching time and optical contrast of the polymers were evaluated via kinetic studies.


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Ünver, Alper; Akovalı, Güneri; Department of Chemistry (2008)
Poly(N-isopropylacrylamide) (PNIPAM) is a smart polymer exhibiting an inverse temperature-solubility relationship with a sharp transition at 32°C in its aqueous solution. Due to its reversible thermo-responsive phase transition behavior at around body temperature, PNIPAM promise a potential for a variety of novel applications especially in biotechnology and medicine. PNIPAM can be produced by conventional polymerization methods, as well as by use of ionizing radiation, primarily by gamma which leads mainly ...
The effect of potassium hydroxide on the polymerization of trichlorophenol, pyrrole and thiophene by microwave initiation
Güngör (Ünsal), Müfide Elif; Kısakürek, Duygu; Department of Chemistry (2008)
The synthesis of black conducting polymer (CP) and/or crosslinked polymers (CLP) and/or radical ion polymer (RIP) and/or white polymers (WP) and/or orange polymer (OP) were achieved by using KOH with TCP, pyrrole and thiophene via microwave energy in a very short time interval. Polymerizations were carried out by constant microwave energy with different time intervals varying from 1 to 25 min; or at constant time intervals with variation of microwave energy from 90 to 900 watt; or varying the water content ...
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Tunç, Yeliz; Hasırcı, Nesrin; Department of Polymer Science and Technology (2009)
High internal phase emulsion polymers (PolyHIPEs) are new generation materials with their high porosity and interconnected open-cell structures and finds applications in areas such as supports for catalytic systems, separation media and tissue engineering scaffolds. Styrene based PolyHIPEs are currently the most popular choice, but solvent compatibility and poor mechanical properties of these materials prevent their applications. Therefore development of new polyHIPEs with desired mechanical and cellular pr...
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Çapar, Gökşen; Yetiş, Ülkü; Department of Environmental Engineering (2005)
A membrane based treatment scheme was developed for the recovery of the print dyeing wastewaters (PDWs) and the acid dye bath wastewaters (ADBWs) of carpet manufacturing industry. The treatment schemes were developed by selecting the best pre-treatment and treatment processes among the alternatives of chemical precipitation (CP), microfiltration (MF), ultrafiltration (UF) and nanofiltration (NF). The best process train for PDW was CP+NF, where organic matter, color, turbidity and total hardness were removed...
Yurtseven, Hasan Hamit (Romanian Academy - Revue Roumaine De Chimie, 2019-03-01)
The temperature-pressure (T-P) phase diagrams are calculated using the mean field models for the solid-fluid (first order) and, the solid-solid transitions of the delta-delta(loc) (second order) and delta(loc)-epsilon (first order) in nitrogen. By expanding the free energy in terms of the order parameters, the phase line equations are derived and they are fitted to the experimental data from the literature for this molecular crystal. For the fitting procedure, the coefficients in the free energy expansion a...
Citation Formats
E. K. Ünver, “Design and synthesis of novel donor-acceptor type monomers and ınvestigation of optoelectronic properties of their polymers,” Ph.D. - Doctoral Program, Middle East Technical University, 2010.