Browsing by Author "Ertan, Salih"

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Citation Count: 18
Design and synthesis of new 4,4′-difluoro-4-bora-3a,4a-diaza-s-indacene based electrochromic polymers
(Pergamon-elsevier Science Ltd, 2013) Algi, Melek Pamuk; Tirkes, Seha; Ertan, Salih; Ergun, Emine Gul Cansu; Cihaner, Atilla; Algi, Fatih; Chemical Engineering
Design, synthesis, optical and electrochemical properties of two novel 4,4'-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) based donor-acceptor compounds, 1 and 2, are reported in order to elucidate the structure-property relationships in BODIPY based materials. Importantly, these compounds provide opportunity to be used as crosslinkers, since they have three electroactive donor sides. Furthermore, these compounds are polymerized successfully via electrochemical polymerization. The corresponding polymers (P1 and P2) are also characterized by using electrochemical and optical methods in monomer-free electrolyte solutions. It is found that both polymers P1 and P2 exhibit reversible oxidation peaks with half wave potentials of 0.70 V and 0.98 V vs. Ag/AgCl, respectively, and they have low optical band gaps (1.88 eV for P1 and 1.72 eV for P2). It is also noted that the polymers exhibit multielectrochromic properties upon doping: P1 can be switched from pink color in the neutral state to blue color in the oxidized state and P2 can be switched from transmissive pink color when neutralized to transmissive blue color when oxidized. (C) 2013 Elsevier Ltd. All rights reserved.
Citation Count: 4
Designing a Solution Processable Poly(3,4-ethylenedioxyselenophene) Analogue
(Amer Chemical Soc, 2018) Ertan, Salih; Cihaner, Atilla; Chemical Engineering
A new derivative (EDOS-POSS) of 3,4-ethylenedioxyselenophene integrated with alkyl-substituted polyhedral oligomeric silsesquioxane (POSS) cage was synthesized and characterized. The electroactive monomer was successfully polymerized via both chemical and electrochemical methods. The obtained polymer called PEDOS-POSS was solution-processable and soluble in common organic solvents like tetrahydrofuran, toluene, dichloromethane, and chloroform. PEDOS-POSS polymer exhibited electrochromic behavior: pure blue when neutralized and highly transparent when oxidized. When compared to the parent PEDOS (1.40 eV with lambda(max) = 673 nm), PEDOS-POSS polymer film has a somewhat higher band gap (1.50 eV with lambda(max) = 668 and 724 nm). Also, PEDOS POSS exhibited high optical contrast ratio (59%) and coloration efficiency (593 cm(2)/C for 95% switching) with a low switching time (0.7 s) due to the presence of POSS cage in the polymer backbone. In addition, PEDOS-POSS polymer film was highly robust and stable under ambient conditions (without purging the electrolyte solution with inert gas). Polymer films demonstrated high electrochemical stability; for example, it retained 76% of its electroactivity after 5000 cycles. Furthermore, the polymers exhibited fluorescent properties and exhibited a reddish orange emission centered about at 640 nm. Based on the findings, to the best of our knowledge, it can be concluded that the polymers are the first examples of soluble and fluorescent PEDOS derivatives. These promising properties make PEDOS-POSS polymer a potential material for bioapplications like imaging the cancer cells as well as optoelectronic applications.
Citation Count: 9
Electrochemical and optical properties of substituted phthalimide based monomers and electrochemical polymerization of 3,4-ethylenedioxythiophene-polyhedral oligomeric silsesquioxane (POSS) analogue
(Elsevier Sci Ltd, 2019) Cakal, Deniz; Ertan, Salih; Cihaner, Atilla; Onal, Ahmet M.; Chemical Engineering
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.
Citation Count: 21
Functionalized polysulfide copolymers with 4-vinylpyridine via inverse vulcanization
(Elsevier Science Bv, 2019) Berk, Hasan; Balci, Burcu; Ertan, Salih; Kaya, Murat; Cihaner, Atilla; Chemical Engineering
A new series of functional polysulfide copolymers called poly(sulfur-random-4-vinylpyridine) (poly(S-r-4VP)) was synthesized via inverse vulcanization technique by ring opening polymerization of elemental sulfur in the presence of 4-vinylpyridine (4VP). The corresponding copolymers can be post functionalized by using amine group in 4VP unit to get polymers bearing various properties. Elemental sulfur was heated up to 160 degrees C and 4VP was added slowly to a clear yellowish orange colored liquid at this temperature. The reaction mixture was vitrified to form a reddish-brown polymeric material at 180 degrees C in 1 h. The products were characterized by using FTIR, NMR, and Raman spectroscopic techniques. Poly(S-r-4VP) copolymers are soluble in common solvents like dichloromethane, chloroform and tetrahydrofuran. Weight-average molecular weights of poly(S-r-4VP) copolymers with different wt% 4VP were measured by using gel permeation chromatography technique. The polysulfide copolymers with different wt% 4VP have high weight-average molecular weights with polydispersity indeces (PDI) in a range from 1.88 to 4.06 measured by gel permeation chromatography. Post functionalization of the copolymer with 50 wt% 4VP as an example was performed successfully by using alkyl bromide to get N-alkyl quaternized 4VP in polymer backbone.
Citation Count: 7
Improvement of optical properties and redox stability of poly(3,4-ethylenedioxythiophene)
(Elsevier Sci Ltd, 2018) Ertan, Salih; Cihaner, Atilla; Chemical Engineering
In 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).
Citation Count: 11
A Low Band Gap Polymer Based on Selenophene and Benzobis (thiadiazole)
(Pergamon-elsevier Science Ltd, 2017) Abdulrazzaq, Mohammed; Ozkut, Merve Icli; Gokce, Gurcan; Ertan, Salih; Tutuncu, Esra; Cihaner, Atilla; Chemical Engineering
A new derivative of benzobis(thiadiazole) based donor-acceptor-donor type monomers, namely 4,7-di (selenophen-2-yl)benzo[1,2-c;4,5-c']bis[1,2,5]thiadiazole (SeBTSe), was synthesized and its polymerization was carried out successfully via electrochemical polymerization in an electrolyte solution of 0.1 M tetrabutylammonium hexafluorophosphate dissolved in dichloromethane. The monomer SeBTSe is a deep red chromophore and it has four redox states: one oxidation, one neutral and two reduction states. The electrochemical behaviour of the corresponding polymer called PSeBTSe was studied by cyclic and differential pulse voltammetry. There is a good agreement between electrochemical (0.62-0.66 eV) and optical (0.63 eV) bandgaps of the polymer. Like the monomer, the ambipolar polymer has four redox states and electrochromic properties: gray beige at neutral state, smoky azurite at oxidized state, beige at first reduced state and dark beige at second reduced state. (C) 2017 Elsevier Ltd. All rights reserved.
Citation Count: 10
A Platform to Synthesize a Soluble Poly(3,4-Ethylenedioxythiophene) Analogue
(Wiley, 2017) Ertan, Salih; Kaynak, Cevdet; Cihaner, Atilla; Chemical Engineering
Alkyl-substituted polyhedral oligomeric silsesquioxane (POSS) cage is combined with 3,4-ethylenedioxythiophene under the same roof. The corresponding monomer called EDOT-POSS is used to get soluble poly(3,4-ethylenedioxythiophene) (PEDOT-POSS) analogue. Both chemically and electrochemically obtained polymers are soluble in common organic solvents like dichloromethane, chloroform, tetrahydrofuran, and so forth. The PEDOT-POSS has somewhat higher band gap (1.71 eV at 618 nm) than its parent PEDOT (1.60 eV at 627 nm) and as expected the PEDOT-POSS exhibits higher optical contrast (74% at 618 nm) and coloration efficiency (582 cm(2)/C for 100% switching), lower switching time (0.9 s), higher electrochemical stability (93% of its electroactivity retains after 5000 cycles under ambient conditions) when compared to the PEDOT. A number of advantages of the PEDOT-POSS over the PEDOT can make it a promising material in the areas of electro-optical applications. (C) 2017 Wiley Periodicals, Inc.
Polihedral oligomerik silseskuokzan içeren boya sentezi ve karakterizasyonu ve hücre görüntüleme için boya olarak kullanımı
(2020) Alfalah, Rıhab Fouzı Salıh; Ertan, Salih; İşgör, Sultan Belgin; Chemical Engineering
POSS içeren polimerlerin önemi elektronik ve fotonik cihazlarda ve birçok yeni uygulamada çokça kullanılması nedeniyle artmıştır. POSS biriminin varlığı, biri organik alkil grupları diğeri inorganik silseskuioksan çekirdekleri olmak üzere iki kısımdan oluşan benzersiz hibrid yapısından dolayı polimere ait mekanik, termal ve fiziksel özellikleri önemli ölçüde artırır. Bu çalışmada, 1-poss-2,5di (tiofen 2-il)-1 H-pirol monomerinin kimyasal polimerizasyonu ile yeni bir poli (tiyofen-pirol-tiyofen) konjuge polimer türevi sentezlendi. Monomer ve polimerin yapısı 1H-NMR ve FT-IR ile karakterize edildi. Sentezlenen boya, PSNS-POSS olarak adlandırıldı ve üç farklı hücrede (MC3T3, L929, and MCF7) hücre boyama özelliği incelendi.
Citation Count: 2
Polyhedral oligomeric silsesquioxane cage integrated soluble and fluorescent poly(3,4-propylenedioxythiophene) dye
(Elsevier Sci Ltd, 2021) Ertan, Salih; Kaya, Murat; Cihaner, Atilla; Chemical Engineering
A new analog of poly (3,4-propylenedioxythiophene) conjugated polymers called PProDOT-POSS, where polyhedral oligomeric silsesquioxane (POSS) nanocage with alkyl substitutions was integrated on the bridge of 3,4-propylenedioxythiophene unit and its structure was confirmed by spectroscopic techniques, was reported. The polymers were synthesized via both chemical and electrochemical polymerization techniques. While chemical polymerization was carried out in the presence of anhydrous FeCl3 as an oxidant, a solution of 0.1 M tetrabutylammonium hexafluoride electrolyte dissolved in a mixture of dichloromethane and acetonitrile (1/3: v/v) was used as an electrolyte solution for electrochemical polymerization. Electro-optical properties of the corresponding polymers were characterized by using electroanalytical techniques such as cyclic voltammetry and square wave potentiometry, and spectrophotometric methods like ultraviolet-visible and fluorescent spectrophotometry. Corresponding polymers obtained both electrochemically and chemically are soluble completely in common organic solvents such as chloroform, toluene, dichloromethane, tetrahydrofuran, etc. Polymer samples both in film and solution forms can be doped/dedoped reversibly by using a chemical oxidant or an external potential. The optical bandgap of the neutral polymer film with a maximum absorption band at 555 nm was calculated as 1.95 eV. Polymers have fluorescent property and excited polymers represented a red/orange light with an emission band centered at 605 nm in toluene. Also, PProDOT-POSS polymers have electrochromic properties under external potentials and they have an optical contrast of 55% at 555 nm between their neutral and oxidized states. Upon oxidation, they showed high transparency and they can switch between redox states in a short time (switching time = similar to 1.0 s) as well as high coloration efficiency (502 cm(2)/C for 95% switching). It can be concluded that POSS based PProDOT polymers can be good candidates for optoelectronic and bioelectronics applications. Short Abstract for Paper Submission: A new analog of poly (3,4-propylenedioxythiophene) conjugated polymers called PProDOT-POSS, was reported with the integrated of alkyl-substituted polyhedral oligomeric silsesquioxane nanocage structure. The polymers were synthesized via both chemical and electrochemical polymerization techniques. Corresponding polymers obtained both electrochemically and chemically are soluble completely in common organic solvents such as chloroform, toluene, dichloromethane, tetrahydrofuran, etc. Polymer samples both in film and solution forms can be doped/dedoped reversibly by using a chemical oxidant or an external potential. The optical bandgap of the neutral polymer film with a maximum absorption band at 555 nm was calculated as 1.95 eV. Polymers have fluorescent property and excited polymers represented a red/orange light with an emission band centered at 605 nm in toluene.
Citation Count: 21
Synthesis and electrochemical polymerization of D-A-D type monomers with thieno [3,4-c] pyrrole-4,6-dione acceptor unit
(Elsevier Sci Ltd, 2018) Cakal, Deniz; Ertan, Salih; Cihaner, Atilla; Onal, Ahmet M.; Chemical Engineering
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.