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Article Citation - WoS: 30Citation - Scopus: 31A New Low-Voltage Polymeric Electrochromic(Elsevier Sci Ltd, 2010) Pamuk, Melek; Tirkes, Seha; Cihaner, Atilla; Algi, FatihDesign, synthesis, and properties of a novel donor-acceptor-donor type low-voltage-driven green polymeric electrochrome, P1, which is based on 8-(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-11-(2,3-dihydrothieno[3,4-b][l,4]dioxin-7-yl)acenaphtho[1,2-b]quinoxaline (1) are highlighted. It is noted that P1 has an ambipolar (n- and p-doping processes) character in 0.1 M tetrabutylammonium hexafluorophosphate/dichloromethame solution and switches to a transmissive blue state upon oxidation. Furthermore, this new polymeric electrochromic candidate exhibits high redox stability, high coloration efficiency and/or contrast ratio, high percent transmittance (%T) and low response time (1.0 s) with a band gap of 1.10 eV-1.25 eV. (C) 2009 Elsevier Ltd. All rights reserved.Article Citation - WoS: 8Citation - Scopus: 8Improvement of Optical Properties and Redox Stability of Poly(3,4-Ethylenedioxythiophene)(Elsevier Sci Ltd, 2018) Ertan, Salih; Cihaner, AtillaIn order to improve the optical properties and redox stability of poly(3,4-ethylenedioxythiophene) (PEDOT) without changing its electrochemical and electrochromic behaviour, it was supported with alkyl-substituted polyhedral oligomeric silsesquioxane (POSS) cage. The corresponding copolymers were obtained electrochemically via potentiostatic or potentiodynamic methods and compared to the parent homopolymers. Electrochemical polymerization of EDOT and POSS containing EDOT called EDOT-POSS in various monomer feed ratios was performed in an electrolyte solution of 0.1 M TBAPF(6) dissolved in a mixture of dichloromethane and acetonitrile (1/3: v/v). Just as PEDOT, the copolymers represented the similar band gap (1.61 eV), redox and electrochromic behaviors. On the other hand, when compared to the parent PEDOT, the presence of POSS cages in the copolymer backbone improved the redox stability and optical properties of PEDOT such as higher percent transmittance change (65% at 621 nm), higher transparency at oxidized state, lower switching time (similar to 1.0 s) and higher coloration efficiency (463 cm(2)/C for 95% switching) as well as higher electrochemical stability (86% of its electroactivity retains after 1750 cycles under ambient conditions).Article Citation - WoS: 11Citation - Scopus: 11Electrochemical and Optical Properties of Substituted Phthalimide Based Monomers and Electrochemical Polymerization of 3,4-Ethylenedioxythiophene Oligomeric Silsesquioxane (poss) Analogue(Elsevier Sci Ltd, 2019) Cakal, Deniz; Ertan, Salih; Cihaner, Atilla; Onal, Ahmet M.A new series of donor-acceptor-donor type trimeric monomers bearing substituted phthalimide units as acceptor units and thiophene and 3,4-ethylenedioxythiophene (EDOT) as donor units was synthesized and characterized. The strength of acceptor units and intramolecular charge transfer between donor and acceptor units were investigated by using electrochemical and optical methods. The main advantage of phthalimide unit over other acceptor units is the ease of its functionalizability. Thus, utilizing this property, a phthalimide derivative (E2P-POSS) bearing polyhedral oligomeric silsesquioxane (POSS) cage was introduced successfully with EDOT and polymerized electrochemically. The corresponding electroactive polymer, PE2P-POSS, has a band gap of 1.72 eV and is an electrochromic polymer: gray when neutralized and eggplant purple when oxidized.Article Citation - WoS: 21Citation - Scopus: 21Synthesis and Electro-Optical Properties of New Conjugated Hybrid Polymers Based on Furan and Fluorene Units(Pergamon-elsevier Science Ltd, 2013) Gunes, Arzu; Cihaner, Atilla; Onal, Ahmet M.A novel series of hybrid monomers containing furan and fluorene units, namely 2-(2-(furan-2-yl)-9H-fluoren-7-yl)furan (FFF), 2,7-di(furan-2-yl)-9H-fluoren-9-one (FOF) and 2-(2-(furan-2-yl)-9,9-dihexyl-9H-fluoren-7-yl)furan (FHF), was synthesized and their electrochemical polymerization was achieved via potential cycling. Optical and electrochemical properties of the polymers, poly(2-(2-(furan-2-yl)9H-fluoren-7-yl)furan (PFFF), poly(2,7-di(furan-2-yl)-9H-fluoren-9-one) (PFOF) and poly(2-(2-(furan2-yl)-9,9-dihexyl-9H-fluoren-7-yl)furan) (PFHF), were investigated and it was found that polymer films exhibited quasi-reversible redox behavior (E-p(ox) =0.92V for PFFF, E-p(ox) = 1.08V for PFOF and E-p(ox) = 0.99V for PFHF) accompanied with a reversible electrochromic behavior, yellow to dark blue for PFFF, orange to green for PFOF and orange to green for PFHF. Their band gap values (E-g) were found to be 2.49, 2.32 and 2.61 eV for PFFF, PFOF and PFHF, respectively. (C) 2012 Elsevier Ltd. All rights reserved.Article Citation - WoS: 25Citation - Scopus: 27A New Processable and Fluorescent Polydithienylpyrrole Electrochrome With Pyrene Appendages(Pergamon-elsevier Science Ltd, 2013) Tirkes, Seha; Mersini, Jetmire; Oztas, Zahide; Algi, Melek Pamuk; Algi, Fatih; Cihaner, AtillaA new hybrid compound, namely 1-(pyren-3-yl)-2,5-di(thiophen-2-yl)-1H-pyrrole (SNS-P), was polymerized via both chemical and electrochemical methods. Chemically obtained soluble polydithienylpyrrole (c-PSNS-P) bearing pyrene appendages is a homogeneous and uniform polymer with a number averaged molecular weight of 15,200 g/mol. The polymer exhibits both multi-electrochromic and fluorescent properties. Upon oxidation, the color of electrochemically obtained polymer (e-PSNS-P) changes from yellowish orange to greenish yellow and to green/blue and finally to blue. In addition, the polymer induces yellowish orange (564 nm) and bright orange emission (613 nm) in solution and solid states, respectively. (C) 2012 Elsevier Ltd. All rights reserved.Article Citation - WoS: 23Citation - Scopus: 25A Neutral State Yellow To Navy Polymer Electrochrome With Pyrene Scaffold(Elsevier Science Bv, 2011) Icli-Ozkut, Merve; Cihaner, Atilla; Oztas, Zahide; Algi, Fatih; Cihaner, Atilla; Cihaner, Atilla; Chemical Engineering; Chemical EngineeringA new pyrene based soluble polymer, namely poly(3,3-didecyl-6-(1-(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4] dioxepin-6-yl) pyren-6-yl)-3,4-dihydro-2H-thieno[3,4-b][1,4] dioxepine), P5, which is synthesized by both chemical and electrochemical methods, is highlighted. The polymer shows both electrochromic and fluorescent properties (the emission of yellow (545 nm) and yellowish green light (524 nm) in solid state and in THF solution, respectively). It is noteworthy that P5 has a specific optical band gap (2.2 eV) to reflect the yellow color in the neutral state. Furthermore, the optical and electrochemical features of the polymer were investigated. (C) 2011 Elsevier B. V. All rights reserved.Article Citation - WoS: 94Citation - Scopus: 100A New Soluble Neutral State Black Electrochromic Copolymer Via a Donor-Acceptor Approach(Elsevier, 2010) Icli, Merve; Pamuk, Melek; Algi, Fatih; Onal, Ahmet M.; Cihaner, AtillaTwo donor-acceptor systems, 2-decyl-4,7-bis(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-2H-benzo[d][1,2,3]triazole (1) and 4,7-bis(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-2,1,3-benzoselenadiazole (2) are explored in order to attain a low bandgap black polymer electrochrome, which is highly difficult to attain due to the complexity of designing such materials. Electrochemical polymerization of 1 and 2 in 1:4 monomer feed ratio was performed in a mixture of acetonitrile and dichloromethane solution containing 0.1 M tetrabutylammonium hexafluorophosphate. It was found that electropolymerization provides a processable neutral state black copolymer, (P(1-co-2)), which absorbs virtually the whole visible spectrum (400-800 nm). (P(1-co-2)) is the first low bandgap (1.45 eV) electropolymerized material, which switches from black color (L = 14.3, a = 0.29, b = 0.35) in the neutral state to transmissive grey (L = 39.2, a = 0.29, b = 0.33) in the oxidized state with 15.3% of the transmittance change at 522 nm. Furthermore, it exhibits excellent operational and/or environmental stability under ambient conditions. (c) 2010 Elsevier B.V. All rights reserved.Article Citation - WoS: 24Citation - Scopus: 23Synthesis and Electrochemical Polymerization of D-A Type Monomers With Thieno [3,4-c] Pyrrole-4,6 Acceptor Unit(Elsevier Sci Ltd, 2018) Cakal, Deniz; Ertan, Salih; Cihaner, Atilla; Onal, Ahmet M.In this study, three new donor-acceptor-donor type monomers bearing 1,3-dibromo-5-(2-ethylhexyl)-4H-thieno [3,4-c]pyrrole- 4,6(5H)-dione (A) as an acceptor unit and thiophene, 3,4-ethylenedioxythiophene (EDOT) and 3,3-didecy1-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepine (didecyl-ProDOT) as donor units were synthesized via Stille cross-coupling reaction and their electrochemical polymerization by repetitive cycling was reported. The electrochemical and optical properties of the monomers ((5-(2-ethyl-liexyl)-1,3-di(thienyl-2-yl)-4H-thienolr-3,4-cl pyrrole-4,6(5H)-dione (TAT), 1,3-bis(2,3-dihydrothieno[3,4-1)] (1,4]dioicin-5-yl)-5-(2-ethylhexyl)-4H-thieno(3,4-c) pyrrole-4,6-(5H)-dione (EAE) and 1,3-bis(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-1)111,41-dioxepin-6-yl)-5-(2-ethylhexyl)-4H-thieno[3,4-apyrrole-4,6(5H)-dione (PAP)) and their corresponding polymers called PTAT, PEAE and PPAP were investigated and it was found that EDOT units containing monomer and polymer (EAE and PEAE) have lower oxidation potentials and lower band gap value as compared to didecyl-ProDOT and thiophene units containing monomers and polymers (PAP, TAT and PPAP, PTAT). Spectroelectrochemical investigations conducted on electrochemically obtained polymer films revealed that polymer films exhibited electrochromic behaviors: brick red to gray for PTAT, blue/violet to highly sky blue for PEAE and blue to highly light blue for PPAP in their neutral and oxidized states, respectively. Moreover, PAP was also polymerized chemically using FeC13 as an oxidizing agent. Both chemically and electrochemically obtained PPAP were found to be soluble in some organic solvents and their dichloromethane solutions can be reversibly oxidized and reduced using antimony pentachloride and hydrazine hydrate solutions, respectively.Article Citation - WoS: 13Citation - Scopus: 13Effect of the Donor Units on the Properties of Fluorinated Acceptor Based Systems(Elsevier Sci Ltd, 2021) Cakal, Deniz; Akdag, Akin; Cihaner, Atilla; Onal, Ahmet M.A new series of monomers in the donor-acceptor-donor array, namely 5-fluoro-4,7-di(furan-2-yl)benzo[c][1,2,5] thiadiazole (F2BT-F), and 5-fluoro-4,7-di(selenophen-2-yl)benzo[c][1,2,5] thiadiazole (S2BT-F), bearing 5-fluorobenzo[c][1,2,5]-thiadiazole as the acceptor moiety and furan and selenophene as the electron donating groups was synthesized and polymerized electrochemically. To compare heteroatom effect, thiophene analogue of newly synthesized (FBT)-B-2-F and S2BT-F namely, (5-fluoro-4,7-di(thiophen-2-yl)benzo[c][1,2,5] thiadiazole (T2BT-F)) and its corresponding polymer were also synthesized. Effect of donor units on the electrochemical and optical properties of fluorinated acceptor based systems was investigated in terms of the effect of different sized heteroatoms in five-membered rings on the dihedral angle and planarity. Theoretical calculations also suggested a deviation from planarity upon fluorination. Moreover, electrochemically obtained polymers possess low bandgap values (1.62 eV-1.68 eV for PF2BT-F and PS2BT-F, respectively) and exhibited electrochromic properties with relatively low switching times.Article Citation - WoS: 2Citation - Scopus: 2New electrochromic copolymers based on spiro bipropylenedioxythiophene and 3,4-ethylenedioxythiophene(Elsevier Science Sa, 2014) Pekel, Lutfiye Canan; Karabay, Bads; Cihaner, AtillaTwo alkylenedioxythiophene derivatives, Spiro bipropylenedioxythiophene (Spiro-BiProDOT) and 3,4-ethylenedioxythiophene (EDOT), were integrated electrochemically in order to attain low band gap electrochromic copolymers. EDOT has a functionality of two, which causes a linear polymer, whereas Spiro-BiProDOT has a functionality of four and its polymerization results in a network polymer. Therefore, by playing the monomer feed ratio, the crosslink degree can be adjusted for the copolymers obtained electrochemically from EDOT and Spiro-BiProDOT monomers in an electrolyte solution of 0.1 M tetrabutyl ammonium hexafluorophosphate dissolved in dichloromethane. It was found that copolymers showed different electrochemical and optical properties at their various redox states when compared to their homopolymers. For example, they could be switched from dark blue in the neutral state to reddish blue at intermediate state and finally to transparent blue in the oxidized state with 45-51% of the transmittance change at 575-595 nm. pi-pi* transition bands of the copolymers can be shifted to higher wavelengths when compared to poly(Spiro-BiProDOT) by increasing the amount of the EDOT units in the polymer backbone. They have low band gaps in the range of 1.65 and 1.73 eV. (C) 2014 Elsevier B.V. All rights reserved.
