Synthesis and characterization of novel quinoxalinebased and thieno[3,4-c]pyrrole-4,6-dione-based conjugated polymers and their applications in organic electronics

Karabağ, Aliekber
In this thesis novel quinoxaline-based and thieno[3,4-c]pyrrole-4,6-dione (TPD)- based monomers were firstly synthesized. Structural analysis of each material synthesized was performed with Nuclear Magnetic Resonance (NMR) Spectroscopy and High-Resolution Mass Spectroscopy (HRMS). Two novel quinoxaline-based monomers were polymerized with electrochemical and/or chemical polymerization whereas TPD-based monomer was polymerized with benzodithiophene-based acceptor via Stille coupling polycondensation reaction. Molecular weight of the polymers was determined by Gel Permeation Chromatography (GPC). The electrochemical behaviors of monomers were studied with Cyclic Voltammetry (CV); on the other hand, the electrochromic properties of polymers were studied with spectroelectrochemical, colorimetric and kinetic studies. ELEC-PQUIN-12C-TH showed both n-dopable/p-dopable and multi-chromic characteristics. In literature, the polymers having such property is rare; therefore, they are used for special purposes such as display systems and smart windows. On the other vi hand, ELEC-PQUIN-2OD-ED and CHEM-PQUIN-2OD-ED showed just p-dopable characteristics. Although such properties were common for almost all conjugated polymers, the polymers showing green color in their neutral state and transmissive grey color in their oxidized state are rare in literature. This kind of polymers having one of the complementary colors (RGB colors) in their neutral states and transmissive grey in their oxidized states are interested in many applications like simple display devices. In addition, both ELEC-PQUIN-2OD-ED and CHEM-PQUIN-2OD-ED displayed greater optical contrasts in the visible region (43% at 728 nm and 45% at 730 nm) compared to the state of the art polymer, PDOPEQ. Furthermore, chemically synthesized quinoxaline-based homopolymer with EDOT side units showed excellent solubility in common organic solvents, especially in CHCl3. To make CHEMPQUIN-2OD-ED soluble in such solvents, it was designed with a long-branched alkyl chain. Since ELEC-QUIN-12C-TH, ELEC-PQUIN-2OD-ED and CHEM-PQUIN- 2OD-ED have promising electrochemical and electrochromic characteristics, they can be easily integrated into today's electrochromic technology even the new generation electrochromic devices. An acceptor unit containing TPD was designed with selenophene building blocks since polymers that utilizes with selenophene side units result in polymers with low band gap energy (<2.0 eV) and broad absorptions with covering NIR region. There is only one report of selenophene attached TPD unit being used in organic solar cells. A number of possible novel polymers can be synthesized using this material. Therefore, selenophene was integrated into TPD central unit as a side unit. In literature, BTA and BDT are also known as promising materials for preparing organic solar cells with a high efficiency. Therefore, novel random copolymer including TPD, BTA and BDT materials were designed and synthesized via Stille coupling. This polymer was then used as donor whereas PCBM, the common and soluble derivative of fullerene was used as acceptor in preparation of organic solar cells. Thickness and morphological properties of poly(TPD-BTA-BDT):PC71BM were investigated and based on these results suitable solar cell devices (ITO/PEDOT:PSS/poly(TPD-BTABDT):PC71BM/LiF/Al) were prepared. Current-Voltage (I-V) properties of each cell were also examined. All solar cell studies were done by using solar simulators in a nitrogen-filled glovebox system (moisture <0.1 ppm; oxygen <0.1 ppm). Data obtained from photovoltaic device was used to calculate Power Conversion Efficiency (PCE) measured under standard AM1.5 G illumination ( ). Without going through the optimization process which has significant effect on PCEs, the material showed 3.0% efficiency. This is a highly promising result and the optimizations are currently underway in our laboratories.


Synthesis and characterization of conjugated polymers with polyhedral oligomeric silsesquioxane pendant groups
Ertan, Salih; Kaynak, Cevdet; Cihaner, Atilla; Department of Polymer Science and Technology (2017)
In this thesis, a series of monomers covalently bonded to polyhedral oligomeric silsesquioxane (POSS) pendant group was designed and synthesized. POSS group is a hybrid organic-inorganic nanostructure with 1 to 3 nm diameter. POSS which has a cage structure is mainly composed of silicon (Si) (at vertices) and oxygen (O) (in the middle of the edge). POSS nanostructure can be modified through the vertices with organic functional groups. POSS groups provide different properties, such as thermal robustness, mec...
Inverted organic solar cell applications of benzodithiophene and benzotriazole bearing alternating copolymers
Bolayır, Eda; Toppare, Levent Kamil; Department of Chemistry (2018)
In this thesis, electrochemical, optical and photovoltaic studies of two novel benzodithiophene and 1,2,3-benzotriazole bearing alternating copolymers were investigated. Benzodithiophene which has a strong electron donating ability and planar structure was used as the donor moiety. On the other hand, benzotriazole was used as an acceptor moiety due to its electron deficient nature. In order to determine the effect of л-bridges, thiophene (P1) and selenophene (P2) moieties were incorporated between the donor...
Synthesis of Novel Benzothiazole-Piperazine Derivatives and Their Biological Evaluation as Acetylcholinesterase Inhibitors and Cytotoxic Agents
GÜRDAL HAKGÖR, ENİSE ECE; Turgutalp, Bengisu; Gulcan, Hayrettin Ozan; Ercetin, Tugba; Şahin, Mustafa; Durmaz, Irem; Atalay, Rengül; Quoc Dat Nguyen, Quoc Dat Nguyen; Sippl, Wolfgang; YARIM YÜKSEL, MİNE (2017-01-01)
Objective and Method: A new series of benzothiazole-piperazine derivatives was synthesized and a complete chemical characterization of the novel compounds was provided. In vitro cytotoxic activities were screened against colorectal (HCT-116), breast (MCF-7) and hepatocellular (Huh7) cancer cell lines by Sulforhodamine B assay.
Synthesis of bistriphenylamine- and benzodithiophene-based random conjugated polymers for organic photovoltaic applications
CETIN, Asli; ISTANBULLUOGLU, Cagla; HACIOGLU, Serife Ozdemir; CEVHER, ŞEVKİ CAN; Toppare, Levent Kamil; Çırpan, Ali (2017-11-15)
In this study, donor-acceptor random polymers containing benzotriazole acceptor and bistriphenylamine and benzodithiophene donors, P1 and P2, were successfully synthesized by Stille coupling polymerization. The effect of bistriphenylamine moiety and thiophene -conjugated linker on electrochemical, spectroelectrochemical, and optical behaviors of the polymers were investigated. Optoelectronic properties and photovoltaic performance of the polymers were examined under the illumination of AM 1.5G, 100 mWcm(-2)...
Effect of ring size on benzimidazole acceptor unit on the properties of donor-acceptor-donor type monomers and their electrochromic polymers
Cansu Ergün, Emine Gül; Önal, Ahmet Muhtar; Cihaner, Atilla; Department of Polymer Science and Technology (2015)
In this thesis, a series of novel benzimidazole-type acceptor units were designed and synthesized. The target acceptors were benzimidazoles including cyclohexane, cycloheptane and cyclooctane rings. Each acceptor group was coupled with 3,4-ethylenedioxythiophene (EDOT) and dihexyl substituted 3,4-propylenedioxythiophene (PRODOT(C6)) donor groups separately and six donor-acceptor-donor (DAD) type monomers were obtained. The main aim of this thesis is to comperatively elucidate the electrochemical and optical...
Citation Formats
A. Karabağ, “Synthesis and characterization of novel quinoxalinebased and thieno[3,4-c]pyrrole-4,6-dione-based conjugated polymers and their applications in organic electronics,” M.S. - Master of Science, Middle East Technical University, 2017.