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Article Citation - WoS: 5Citation - Scopus: 6An Electrochromic Polymer Based on Cyclopenta[2,1-B;3,4 Effect of a Single Atom Alteration on the Electrochemical and Optical Properties of the Polymer Backbone(Elsevier Science Sa, 2020) Tutuncu, Esra; Varlik, Bengisu; Kesimal, Busra; Cihaner, Atilla; Ozkut, Merve IcliAn electrochromic polymer, namely "poly(2,6-(3,3-didecyl-3,4-dihydro-2H-thieno [3,4-b] [1,4]dioxepin-6-yl)-4,4-dioctyl-4H-cyclopenta[2,1-b;3,4-b']dithiophene)" (P1), was electrochemically synthesized successfully, and its electrochemical and optical properties were investigated. The band gap of the polymer P1 was calculated as 1.77 eV with -5.45 eV Highest Occupied Molecular Orbital (HOMO) and -3.68 eV Lowest Unoccupied Molecular Orbital (LUMO) energy levels. The polymer P1 is bluish purple when neutralized and highly transparent greenish purple when oxidized. This color change was observed around 1.4 s between its redox states and optical contrast ratio was found to be as 49 % and 53 % with 234 cm(2)/C and 239 cm(2)/C coloration efficiencies at 590 nm and 634 nm, respectively. Moreover, the properties of this polymer were compared to its analogues and also during this comparison the effect of alteration of a single atom in the pendant unit was tried to be understood.Article Citation - WoS: 44Citation - Scopus: 45A Novel Electrochromic and Fluorescent Polythienylpyrrole Bearing 1,1′-Bipyrrole(Pergamon-elsevier Science Ltd, 2009) Cihaner, Atilla; Mert, Olcay; Demir, Ayhan S.A novel conducting polymer was successfully synthesized via electropolymerization of 1-(1H-pyrrol-1-yl)-2,5-di(thiophen-2-yl)-1H-pyrrole. The electrochemical and electro-optical properties of the corresponding polymer, which was the first example of polymer containing 1,1'-bipyrrole units, were elaborated using electroanalytical and spectroscopic techniques. Cyclic voltammograms and electro-optical studies showed that the polymer has a stable and well-defined reversible redox process as well as electrochromic behavior. The processable polymer film also possessed a yellowish orange light emitter property. (C) 2008 Elsevier Ltd. All rights reserved.Article Citation - WoS: 94Citation - Scopus: 95A New Conducting Polymer Bearing 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (bodipy) Subunit: Synthesis and Characterization(Pergamon-elsevier Science Ltd, 2008) Cihaner, Atilla; Algi, FatihA new monomer system based on thiophene, pyrrole and 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene dye (SNS-BODIPY) was synthesized and its corresponding polymer (PSNS-BODIPY) was obtained via repetitive cycling or constant potential electrolysis in 0.1 M tetrabutylammonium hexafluorophosphate dissolved in dichloromethane. The PSNS-BODIPY film has very stable and well-defined reversible redox couples during p-doping process. Multi-electrochromic polymer film has a band gap of 2.9 eV with two absorption bands in its neutral state at 351 and 525 nm, attributed to the polymer backbone and BODIPY subunits, respectively. The percentage transmittance changes between both states (neutral and oxidized) were found as 12.1% for 351 nm and 17.7% for 525 nm in the visible region as well as 46.2% for 1050 nm in the near-infrared region. Beyond the robustness, the PSNS-BODIPY film has high redox stability (retaining 53.3% of its electroactivity at 351 nm after 2000 switching) with a low response time of 1.0 s. (C) 2008 Elsevier Ltd. All rights reserved.Article Catalyst-Free Synthesis of Thiourea-Linked Dumbbell-Shaped POSS for Ultrasensitive Determination of Prilocaine in Human Blood With Computational Insights(Elsevier, 2026) Bilge, Selva; Bayraktar, Ece Nur; Erkmen, Cem; Balci, Burcu; Abofoul, Anas; Ozkut, Merve Icli; Cihaner, AtillaAlthough various electrochemical sensors have been reported for the determination of local anesthetic drugs, most existing platforms suffer from limited sensitivity, insufficient surface stability, or inadequate electron-transfer efficiency, particularly when applied to complex biological matrices. Moreover, the potential of hybrid polyhedral oligomeric silsesquioxane (POSS)-based nanostructures combined with metal oxide nano-particles for improving electroanalytical performance has not yet been thoroughly explored. In this study, a high-sensitivity electrochemical nanosensor was developed for the determination of prilocaine (PC), an amide-type local anesthetic, using a glassy carbon (GC) electrode modified with POSS-titanium dioxide (TiO2) nano-particles (Nps). The combination of modifications provided a unique electrode surface by combining the high stability of POSS with the strong adsorption properties of TiO2 Nps, thereby increasing both surface loading and adsorption capacity. To elucidate the structure of the modification combination, 1H and 13C nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopic techniques, as well as Brunauer-Emmett-Teller (BET), X-Ray diffraction (XRD), Electrochemical impedance spectroscopy (EIS), and high-resolution transmission electron microscopy (HRTEM) analysis techniques were used, respectively. The analytical performance of the developed nanosensor was systematically optimized using differential pulse voltammetry (DPV), adsorptive stripping differential pulse voltammetry (AdSDPV), square wave voltammetry (SWV), and adsorptive stripping square wave voltammetry (AdSSWV) techniques. As a result of the optimization studies, the lowest limit of detection (LOD) was 3.66 x 10-8 M with the AdSSWV technique. DFT results corroborated the mechanism, indicating ring-centered electron donation (HOMO) and adsorption-favored N/O regions (MEP). Low LOD values were also recorded with other techniques, demonstrating the method's high sensitivity in analyte detection. In real sample analysis tests, PC recovery value in human blood samples was determined to be 98.69% using the AdSDPV technique. Despite the matrix effect, the nanosensor demonstrated high accuracy and reproducibility. The results indicate that the developed POSS-TiO2 Nps modified GC electrode sensor offers a high-performance, reliable, and good electrochemical detection platform suitable for use in biological and clinical applications.Article Citation - WoS: 7Citation - Scopus: 6Side Chain Effect on the Electrochemical and Optical Properties of Thieno[3,4-c]pyrrole-4,6-dione Based Donor-Acceptor Donor Type Monomers and Polymers(Royal Soc Chemistry, 2023) Cakal, Deniz; Arabaci, Elif Demir; Yildirim, Erol; Cihaner, Atilla; Onal, Ahmet M.In organic pi-conjugated materials, side chains play great roles that impact far beyond solubility. In this work, we mainly focused on the synthesis of new donor-acceptor-donor (D-A-D) type conjugated monomers and their corresponding polymers appending thieno[3,4-c]pyrrole-4,6-dione (TPD) acceptor with a new side chain, fluorene (Fl), to investigate the side chain effect. In this context, to reveal the precise effect of the side chains on the optical and electrochemical properties of the monomers and polymers synthesized in this work, four series of D-A-D monomers, each containing a TPD core unit with a different side chain, are compared and discussed in relation to each other. Notably, it was discovered that the TPD acceptor unit can be modified with any functional group other than common alkyl chains to impart new functionalities by maintaining their superior optoelectronic properties. New types of side chains can be used to tune the physical characteristics, such as solubility, absorption, emission, and molecular packing. In this work, Fl-appended monomers as a new class of D-A-D type pi-conjugated molecules containing 3,4-ethylenedioxythiophene (EDOT (E)) and 3,4-propylenedioxythiophene (ProDOT (P)) donor units were studied and it was found that 1,3-bis(2,3-dihydrothieno[3,4-b][1,4]dioxin-5-yl)-5-(9H-fluoren-2-yl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione (E(Fl)) and 1,3-bis(3,3-didecyl-3,4-dihydro-2H-thieno[3,4-b][1,4]dioxepin-6-yl)-5-(9H-fluoren-2-yl)-4H-thieno[3,4-c]pyrrole-4,6(5H)-dione (P(Fl)) exhibited reasonable quantum yields and their corresponding polymers revealed ambipolar character with slightly lower band gap as compared to the previous analogues containing other side chains. Observed experimental results were elucidated by first principle calculations. In this paper, we discussed that using side chain engineering is an effective strategy for improving next-generation organic pi-conjugated materials with the desired properties.Article Citation - WoS: 20Citation - Scopus: 22Electrochemical and Optical Properties of an Azo Dye Based Conducting Copolymer(Tubitak Scientific & Technological Research Council Turkey, 2009) Cihaner, Atilla; Algi, FatihThe electrochemical and optical properties of a novel conducting copolymer called poly(2,5'-dimethyl-[4-(2,5-di-thiophen-2-yl-pyrrol-1-yl)-phenyl]azobenzene-co-(3,4-ethylenedioxythiophene)) (poly(1-co-EDOT)) are reported. Electrochemically synthesized poly(1-co-EDOT) based on the azo dye has a well-defined and reversible redox couple (0.37 V vs. Ag/AgCl) with good cycle stability. The copolymer film exhibits high conductivity (13 S/cm) as well as electrochromic behavior (magenta when neutralized and transmissive sky blue when oxidized). Furthermore, electro-optically active copolymer film has a low band gap of 1.79 eV with a pi-pi* transition at 555 nm.Article Side Chain Effect on the Electrochemical and Optical Properties of Tpd Based Donor Acceptor Donor Type Monomers and Polymers(Molecular Systems Design and Engineering, 2023) Çakal, Deniz; Demir Arabacı, Elif; Yıldırım, Erol; Cihaner, Atilla; Önal, Ahmet M.In organic π-conjugated materials, side chains play great roles that are far beyond solubility. In this work, we mainly focused on the synthesis of new donor-acceptor-donor (D-A-D) type conjugated monomers and their corresponding polymers appending TPD acceptor with a new side chain, fluorene, to investigate the side chain effect. In this context, to reveal the precise effect of the side chains on the optical and electrochemical properties of the monomers and polymers synthesized in this work, four series of D-A-D monomers, each containing a TPD core unit with a different side chain, have been discussed in comparison to each other. Notably, it was discovered that TPD acceptor unit can be modified by any functional group other than common alkyl chains to impart new functionalities by keeping their superior optoelectronic properties. New kind of side chains can be used to tune the physical characteristics such as solubility, absorption, emission and molecular packing. In this paper, fluorene-appended monomers as a new class of D-A-D type π-conjugated molecules were studied and it was found that E(Fl) and P(Fl) exhibited resonable quantum yields and their corresponding polymers revealed ambipolar character with slightly lower band gap as compared to the previous analougs containing other side chains. Observed experimental results were elucidated by first principle calculations. In this paper, we discussed that using side chain engineering is an effective strategy to improve next-generation organic π-conjugated materials with the desired properties.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: 8Citation - Scopus: 8Electropolymerization and Ion Sensitivity of Chemiluminescent Thienyl Systems(Pergamon-elsevier Science Ltd, 2009) Asil, Demet; Cihaner, Atilla; Onal, Ahmet M.Redox driven chemiluminescent (CL) compounds based on thienyl and pyridazine systems, namely 2,3-dihydrothieno(3,4-d)pyridazine-1,4-dione (T-Lum) and 5,7-di-thiophen-2-yl-2,3-dihydrothieno[3,4-d]pyridazine-1,4-dione (TTT-Lum), were synthesized. Soluble compounds both in organic media and basic aqueous solution were found to give CL and electroluminescent (EL) reactions by the treatment of oxidants (H2O2 and KMnO4) and by an external potential pulse on the working electrode, respectively. Furthermore, the CL reaction can be speeded up by Fe3+ ion or blood samples. On the other hand, one of the compounds. TTT-Lum, can be polymerized successfully via electrochemically both in 0.1 M LiClO4/acetonitrile containing 5% of borontrifluoro diethylether (BF3-Et2O) and neat BF3-Et2O solution. The corresponding polymer film (PTTT-Lum) bearing CL units has a very stable and a well-defined reversible redox couple. Also, the electrochromic polymer film has a band gap of 1.74 eV and exhibits EL behavior. (C) 2009 Elsevier Ltd. All rights reserved.Article Synthesis and Characterization of a Luminol Based Chemiluminescent Trimeric System(Springer/plenum Publishers, 2023) Kesimal, Busra; Balci, Burcu; Cakal, Deniz; Onal, Ahmet M.; Cihaner, AtillaA luminol based chemiluminescent trimeric system, namely 2,3-dihydro-5,8-di(thiophen-2-yl)phthalazine-1,4-dione (T2B-Lum), bearing thiophene rings as donor units and 2,3-dihydrophthalazine-1,4-dione as an acceptor unit was synthesized in two steps via donor-acceptor-donor approach using two different methods. It was found that T2B-Lum emits chemiluminescent light when exposed to H2O2 in a basic medium, and the presence of substituents and the type of aromatic ring bearing chemiluminescent active group have a direct effect on the compound's sensitivity. Among the members of a large family of metal ions, fluorescent and chemiluminescent T2B-Lum exhibited high sensitivity to Cu2+ and Fe3+ ions. Except for other metal cations (silver(I), cadmium(II), cobalt(II), iron(III), lithium(I), magnesium(II), manganese(II), nickel(II), zinc(II)), it has been observed that T2B-Lum is mostly sensitive to copper(II) ions with a detection limit value of 2.2 x 10(- 3) M. On the other hand, T2B-Lum was also found to exhibit a high sensitivity to extremely dilute aqueous solutions (e.g., 1:50.000 dilution) of blood samples, making it a promising candidate for use in forensic applications.
