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Öğe 3-Aminopropyltriethoxysilane-mediated (phenoxy-imine) polymers: synthesis and characterization(Springer, 2019) Kaya, İsmet; Boz, Mihriban Esma; Kolcu, Feyza3-Aminopropyltriethoxysilane (3-APTES)-functionalized phenoxy-imine polymers exhibiting enhanced thermal properties have been synthesized by oxidative polycondensation using 4-hydroxybenzaldehyde, 2-hydroxy-3-methoxybenzaldehyde, 2-hydroxy-1-naphthaldehyde, 2-hydroxybenzaldehyde and 3,4-dihydroxy benzaldehyde; subsequently, the polymerized aldehydes polymers were grafted by integrating 3-APTES to form poly(imine)s. All compounds characterized by FT-IR, UV-Vis, H-1-NMR and XPS analyses revealed the existence of Si-O-C bonds in the silanized compounds. Thermal behavior (TG-DTA-DSC) of the synthesized polymers has been determined using thermogravimetric and differential scanning calorimetry techniques. The thermal stability of the phenoxy-imine polymers was enhanced significantly by incorporation of 3-APTES into the polymer backbone. Size exclusion chromatography provided information about the number average molecular weight (M-n), weight average molecular weight (M-w) and polydispersity index values of phenoxy-imine polymers. Photoluminescence and morphologic properties of the polymers at different amplifications were analyzed. The results of optical, thermal and electrical conductivity measurements indicated that the phenoxy-imine polymers were crucial due to their high electrical conductivity and heat retardancy as well as the lowest band gap for P3 derived from 2-hydroxy-1-naphthaldehyde and 3-APTES. Graphical abstract3-Aminopropyltriethoxysilane-functionalized phenoxy-imine polymers were synthesized using the polymerized aldehydes. The results of optical, thermal and electrical conductivity measurements indicated that the phenoxy-imine polymers were crucial due to their highest electrical conductivity and heat retardancy as well as the lowest band gap for P3 derived from 2-hydroxy-1-naphthaldehyde and 3-aminopropyltriethoxysilane. [GRAPHICS] .Öğe A Schiff base based on triphenylamine and thiophene moieties as a fluorescent sensor for Cr (III) ions: Synthesis, characterization and fluorescent applications(Elsevier Science Sa, 2020) Kolcu, Feyza; Erdener, Diğdem; Kaya, İsmetA Schiff base fluorescent sensor was designed for selective detection of Cr3+ ions in aqueous solution. The procedure for the study was fulfilled in three steps which comprised the synthesis of 4-nitro-triphenylamine (TPA-NO2), 4-amino-triphenylamine (TPA-NH2) and Schiff base (TPA-Th) using 2,2′-bithiophene-5-carboxaldehyde, respectively. Structural characterization of the purely synthesized compounds was acquired by using UV–Vis, FT-IR, 1H NMR and 13C NMR analyses. Their electrochemical, thermal, and the optical sensor properties for metal ions were enlightened by cyclic voltammetry (CV), thermal-TG-DTA and photoluminescence (PL) techniques, respectively. Non-fluorescent TPA-Th displayed a fluorescence enhancement after chelation with Cr3+ ions with high selectivity and overall emission change of 59-fold at an excitation wavelength of 320 nm. The limit of detection (LOD) value was as low as 1.5 × 10−6 M for Cr3+ ions, accompanied by an association constant (Ka) of 2.8 × 104 M−1. TPA-Th was beneficial for the design and development of metal-complexed fluorescent sensor and light emitting devices.Öğe A study of the chemical and the enzyme-catalyzed oxidative polymerization of aromatic diamine bearing chlor substituents, pursuant to structural, thermal and photophysical properties(Pergamon-Elsevier Science Ltd, 2020) Kolcu, Feyza; Kaya, İsmet2,5-Dichloro-p-phenylenediamine (ClPDA) is a member of aromatic diamines. This descriptive study sought the oxidative polymerization of ClPDA with hydrogen peroxide using the enzyme-catalyzed and the chemical oxidative ways for the syntheses of P-ClPDA-E and P-ClPDA-O, respectively. Neutral ClPDA was easily oxidized to the polymers composed of ortho-coupled constitutional moieties with lower optical and electrochemical band gaps than those of ClPDA using two polymerization routes. The elucidation of molecular structures obtained from the enzyme-catalyzed and the chemical oxidative polymerization of ClPDA were carried out by the FT-IR, UV-Vis, H-1 NMR and C-13 NMR techniques, concluded with the ladder-type and the perrnigraniline-type polymer formation as a result of two different polymerization processes. Solvent effects in selected polar solvents on the optical properties of P-ClPDA-E and P-ClPDA-O were also analyzed. Thermal and electrochemical properties of the products were fulfilled using TG-DTA-DSC and cyclic voltammetry (CV) techniques, respectively. The number of average molecular weight of P-ClPDA-E was found to be higher than that of P-ClPDA-O. The degradation of ladder-type structure of P-ClPDA-E with higher M-w value started at higher temperatures compared to P-ClPDA-O, which was composed of benzenoid and quinoid units. In response to the excitation of UV light, only P-ClPDA-E radiated blue light with high intensity and a quantum yield of 23% in DMF depending on photoluminescence measurement. Scanning Electron Microscopy (SEM) views set a precedent for the agglomerates of particles. The enzyme-catalyzed oxidation of ClPDA resulted in the formation of nanospheres of PClPDA-E. In course of a change in the polymerization method, the morphology of the chemical oxidative polymerized ClPDA (P-ClPDA-O) was seen spongy with some pores.Öğe An investigation of the enzymatic oligomerization of nitro-substituted phenylene diamine: Thermal and fluorescence properties(2024) Kolcu, Feyza2-nitro-p-phenylenediamine, an aromatic diamine, was studied for its oxidative oligomerization with H2O2 using enzyme-catalyzed oligomer synthesis. Characterization of molecular structures was performed utilizing ultraviolet-visible (UV-Vis) spectrophotometer, Fourier-transform infrared spectroscopy (FT-IR), and nuclear magnetic resonance (NMR) techniques, identifying phenazine-bridged oligomer resulting from the enzymatic oligomerization process. Based on the results of gel permeation chromatography (GPC) analysis, the synthesized compound was identified as being in an oligomeric form. Conversely, the number of repeating units, as determined by Mw, was found to be 28. The solvent effect on the optical features of the synthesized oligomer in polar solvents was analyzed. The degradation of phenazine-type structures in the oligomer occurred at higher temperatures than that of the monomer. Under visible light excitation, the oligomer exhibited green light emission with a quantum yield (QY) of 6.2% in N,N-dimethylformamide (DMF). 2-nitro-p-phenylenediamine was readily oxidized into an oligomer with ortho-coupled constitutional units, having a lower electrochemical band gap than the monomer, via the enzymatic oligomerization route. Scanning electron microscopy revealed that enzyme-catalyzed oxidation of monomers exhibited a spongy morphology with some poresÖğe Application of a novel anthracene derivative polymer for sensitive voltammetric determination of chloramphenicol in pharmaceutical and food samples(Pergamon-Elsevier Science Ltd, 2025) Karakaya, Serkan; Kaya, İsmet; Kolcu, Feyza; Dilgin, YusufThe application of new polymers for the preparation of modified electrodes is an interesting research area, which is highly significant in the electrochemical antibiotic drug sensors for food safety and environmental sides. Herein, we successfully report the synthesis of a new anthracene-based monomer (N1, N4-bis(anthracene-9-ylmethylene)-2,5-dichlorobenzene-1,4-diamine (ADCA) and Poly(ADCA) modified carbon-based electrode has been used in sensitive and selective differential pulse voltammetric determination of chloramphenicol (CPNL) for the first time. In this platform, the proposed monomer was successfully electro-polymerized onto a cheap, lowcost, and disposable pencil graphite electrode (PGE). The cyclic and differential pulse voltammetric experiments proved that the polymer-modified electrode Poly(ADCA)/PGE) has great electrocatalytic efficiency on the reduction of CPNL. The proposed platform shows a comparable performance in terms of wide linear ranges (2.0-100 and 100-1000 mu M), a low detection limit (0.55 mu M) and high sensitivity (11405 mu A mM- 1 cm- 2) by differential pulse voltammetry (DPV). Additionally, the Poly(ADCA)/PGE exhibited high selectivity and antiinterference facilities for the CPNL. The fabricated sensor showed a promising potential for the determination of CPNL in food (honey, and milk), bottled water, and pharmaceutical (eye ointment) samples with acceptable accuracies and precisions.Öğe Carbazole-based Schiff base: A sensitive fluorescent ‘turn-on’ chemosensor for recognition of Al(III) ions in aqueous-alcohol media(Elsevier, 2022) Kolcu, Feyza; Kaya, İsmetCarbazole-based Schiff base chemosensor was synthesized in one-pot synthesis using 2hydroxy-1-naphtaldehyde for fluorescent sensing of Al3+ ions. Characterization of the ligand (L) was revealed through spectroscopic and physicochemical techniques. The fluorescence emission responses of L to various metal ions and anions were investigated. The chelation was studied by UV-vis, 1H NMR, LC-MS/MS, fluorescence titration and Job's plot analysis. Bathochromic shift resulted from charge transfer from L to electrophilic Al3+ ion was observed in the chelation of L with Al3+. The potentiality of L to be a distinguished probe to detect Al3+ ions was due to a chelation enhanced fluorescence (CHEF) effect, concomitant with noticeable fluorescent enhancement. A significant fluorescence enhancement at 533 nm was observed in ethanol-water (1:1, v/v) solution upon addition of Al3+ along with a distinct color change from yellow to white. Non-fluorescent ligand exposed highly sensitive turn-on fluorescent sensor behavior for selectively sensing Al3+ ions via 1:1 (ligand:metal) stoichiometry. The ligand's specificity in the existence of other tested metal ions and anions indicated no observation in color change. The ligand-Al3+ complex formation was reversible upon addition of chelating agent EDTA. The ligand interacted with Al3+ ions with an association constant of Ka = 5 x 104 M-1. The limit of detection (LOD) was found to be 2.59 x 10-7 M. The synthesized Schiff base could efficiently detect Al3+ ions as a fluorescent sensor. (c) 2022 Published by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Öğe Characterization and spectroscopic study of enzymatic oligomerization of phenazopyridine hydrochloride(Elsevier, 2019) Kolcu, FeyzaPhenazopyridine hydrochloride (PHP), an azo dye, has been used in pharmaceutical chemistry. This study delineated the synthetic pathway of enzymatically oligomerized based on PHP. The molecular characterization of O-PHP was determined via UV-vis, infrared, H-1 NMR and C-13 NMR techniques. Solvent effect on the electronic absorption of O-PHP was investigated. Further analysis was fulfilled by photoluminescence (PL), thermal analysis (TG-DTA and DSC) and electrochemical (CV) measurements. PL measurements resulted in the response of O-PHP with bicolor light emissions upon Ultra-Violet and visible light, respectively. CV method was utilized to evaluate the HOMO-LUMO energy levels and the electrochemical (E-g') band gaps of the monomer and the oligomer. Optical and electrochemical band gaps of O-PHP were lower than those of PHP, confirming the accomplished synthesis of pi-conjugated structure of O-PHP. Scanning Electron Microscopy (SEM) technique was carried out to study the surface morphology of O-PHP. Additionally, the results of thermal studies of TG-DTA and DSC techniques showed that O-PHP was thermally stable compound. (C) 2019 Elsevier B.V. All rights reserved.Öğe Chemical Oxidative Polymerization of 1,3-Phenylenediamine Dichloride in Aqueous Solution: Synthesis and Characterization(Iğdır Üniversitesi, 2025) Kolcu, Feyza; Kaya, İsmetAn aromatic diamine compound of 1,3-phenylenediamine dichloride (monomer), containing two polymerizable functional groups was submitted to selective polymerization in water via oxidative coupling polymerization with sodium hypochloride as the oxidant. Characterization of the synthesized polymer was performed utilizing UV-Vis, FT-IR, SEM, and photoluminescence techniques, identifying benzeneoid an quinoid units along the polymer chain. Based on the results of Gel Permeation Chromatography (GPC) analysis, the synthesized compound was identified as being in a polymeric form. The number of repeating units, as determined from Mw and Mn, was calculated as 151 and 86, respectively. Under visible light excitation, the polymer exhibited green light emission with a quantum yield of 11.2% in DMF. The monomer is oxidized via oxidative polymerization to a polymer with a higher electrochemical band gap. Scanning Electron Microscopy (SEM) revealed that the polymer particles with polyhedral and irregular sharp edges as well as spherical in the range from micro to nanometer in size were exhibited in the morphology of polymer.Öğe Comparative Study of Bis-Schiff Case Containing Conjugated Oligomers Based on Phosphate and Silane Moieties: Investigation of Photophysical and Thermal Properties(Amer Chemical Soc, 2024) Kolcu, Feyza; Çulhaoğlu, Süleyman; Kaya, İsmetOligo(azomethine)s bearing phosphate and silane moieties were the subject of an investigation within this study. The initial stage involved the synthesis of two Schiff base monomers, denoted as SCH-1 and SCH-2 (SCHs), each possessing a pair of hydroxyl functional groups. This was achieved through a loss of water between the aldehyde and diamine precursors. Subsequently, the Schiff base entities were subjected to oligomerization through HCl-mediated elimination due to the interaction between the hydroxyl groups of the Schiff bases and the chlorine moieties of dichlorodiethylsilane (Si) or phenyl dichlorophosphate (P). This procedure yielded distinct P-oligo(azomethine) (P1-P, P2-P) and Si-oligo(azomethine) (P1-Si and P2-Si) structures corresponding to each precursor. The molecular structures of the synthesized Schiff base monomers and oligo(azomethine)s were elucidated employing Fourier transform infrared, H-1 NMR, and C-13 NMR techniques. Thermal properties of the resulting products were assessed by utilizing thermogravimetric analysis (TG-DTG/DTA and DSC) techniques. Scanning electron microscopy (SEM) was employed to acquire high-resolution images and detailed surface information on the samples. Additionally, X-ray diffraction was employed to analyze the phase properties of the solid samples. Furthermore, the optical band gap (E-g) values of the resulting P-oligo(azomethine)s and Si-oligo(azomethine)s were determined utilizing UV-vis spectrophotometer. The relatively low band gap values exhibited by the synthesized oligo(azomethine)s were indicative of their potential suitability as semiconductive materials in the realm of electronic and optoelectronic device fabrication. Photoluminescence (PL) measurements disclosed a green emission profile upon excitation by blue light. The oligo(azomethine)s incorporating methoxy groups demonstrated a red shift in comparison to their counterparts with methyl groups. Remarkably, no discernible fluctuations in fluorescence were observed over a 3600 s interval under consistent conditions. This observation underscored the inherent stability of the PL emission across the spectral range of exciting light. Thermal analyses unveiled high thermal stability of the synthesized oligo(azomethine)s, sustaining their structural integrity up to 220 degrees C. The char % of P-oligo(azomethine)s and Si-oligo(azomethine)s were observed to fall within the range of 29.45-55.47% at 1000 degrees C. SEM images revealed the absence of pores on the surface of P2-Si, which exhibited the highest limiting oxygen index and thermal heat release index (T-HRI) values.Öğe Conducting polymer composites based on LDPE doped with poly(aminonaphthol sulfonic acid)(Elsevier Science Bv, 2018) Doğan, Fatih; Şirin, Kamil; Kolcu, Feyza; Kaya, İsmetThe paper presents the mechanical, morphological, thermal and the electrostatic charge dissipative (ESD) properties of binary blends of low-density poly (ethylene) (LDPE) blended with poly (1-amino-2-hydroxy naphthalene-4-sulfonic acid) (PANSA). Blends were prepared by loading 0.5, 1.0 and 3 wt% of PANSA into LDPE matrix in the twin-screw micro extruder. The interaction between PANSA and LDPE was then characterized by FT-IR, DSC, TG, DMA, AFM, SEM and X-RD techniques. The resulting polyolefin-based blends were also investigated by stress-strain curves in order to analyze some physico-mechanical properties. Percentages of the crystallinity of the blends were calculated by FT-IR, DSC and X-RD analyses. The conductivity of PANSA/LDPE blends was determined to be in the range of 10(-11) - 10(-12) S cm(-1) using ESD applications. The antistatic decay time of blend films was found to be of the order of 0.103-1.721 secat corona voltages between -3 kV and 3 kV, concluding that PANSA can be used as an effective ESD material for antistatic coatings of LDPE.Öğe Efficient one-pot strategy for fluorescent conjugated polymers derived from 8-amino-1-naphthalene-3,6-disulfonic acid: Synthesis, thermal and optical properties(Elsevier, 2025) Kaya, İsmet; Akyüz, Burçin; Kolcu, Feyza; Yıldız, SerkanSchiff base polymers, also known as poly(imines) or poly(azomethine)s, constitute a subset of conjugated polymers. The Schiff base compound was synthesized via the condensation reaction between 8-amino-1-naphthalene-3,6-disulfonic acid and 4-hydroxybenzaldehyde. Subsequently, both 8-amino-1-naphthalene-3,6-disulfonic acid and its Schiff base derivative were polymerized into a poly(naphthol) (PANAPDSA) and Schiff base polymer (PANAPDSASB) under alkaline condition using H2O2 (35 % aqueous solution) as oxidant via oxidative polycondensation (OP). The chemical structures of the synthesized compounds were approved using NMR, FT-IR, UV-Vis, element and LC-MS/MS spectroscopic techniques. The synthesized polymers exhibited lower optical and electrochemical band gaps compared to their respective monomers, suggesting their potential utility as semiconductor materials. The poly(naphthol) derivative exhibited high fluorescent emission intensity of 1000 a.u. when excited at 300 nm with a photoluminescence (PL) emission quantum yield of 13.6 % at 392 nm of emission wavelength in N,N-dimethylformamide (DMF) solution. Weight average molecular weight (Mw) values of PANAPDSA and PANAPDSASB ranged from 9500 Da to 11200 Da, with PDI values between 1.12 and 1.13. The synthesis of conjugated polymers could hold significant importance in technological advancements.Öğe Facile one-pot synthesis of water-soluble conjugated polymers derived from 7-amino-4-hydroxy-2-naphthalenesulfonic acid: Synthesis and photoluminesence properties(Elsevier, 2022) Kaya, İsmet; Akyüz, Burçin; Kolcu, Feyza; Söyüt, HakanSchiff base polymers or poly(imine)s are a conjugate polymers group. Due to their high thermal stability, conjugated polymers (CPs) are widely used in the production of electronic equipment such as accumulators, solar cells, rechargeable cells, conductive coating, photo-receptors, ion exchangers, photo-diodes, sensors, electrochromic devices, and light emitting diodes. That's why the synthesis of new conjugated polymers is essential in technological applications. The Schiff base compound was synthesized through the condensation reaction between 7-amino-4-hydroxy-2-naphthalene sulphonic acid and 4-hydroxybenzaldehyde, and the substance obtained was transformed into a polyimine in an alkali medium by the addition of H2O2 (35% aqueous solution) as an oxidant. In addition, a polynaphtol derivative was obtained in an alkali medium from 7-amino-4-hydroxy-2naphthalene sulphonic acid with the participation of H2O2 (35% aqueous solution) used as the oxidant. The structures of the synthesized compounds were approved using NMR and FT-IR techniques. Solvatochromism was observed as a bathochromic shift for the polymers, particularly in H2O2 (35% aqueous solution). Bicolored fluorescent light emission intensities of the poly-naphtol derivative were 786 a.u. and 394 a.u when excitation took place at 355 and 440 nm, respectively, with had the emission QY of 8.6% for 410 nm of PL emission in DMF. The synthesized polymers, which had lower optical and electrochemical band gaps than their regarding monomers, could be evaluated as semi-conductors. Mw values of polymers varied between 6365 Da and 8900 Da, and their PDI values were found to be between 1.148 and 1.166.Öğe Influence of the enzymatic and the chemical oxidative polymerization of trifluoromethyl-substituted aromatic diamine on thermal and photophysical properties(John Wiley and Sons Ltd, 2023) Söyüt, Hakan; Kolcu, Feyza; Kaya, İsmet; Yaşar, Alper ÖmerSemi-conductive polymers have been used in a few area applications such as coatings, accumulators, solar cells, rechargeable batteries, ion sensors, photoreceptors, light-emitting diodes and electrochromic instruments. Poly(4-(trifluoromethyl)benzene-1,2-diamine)s of Poly(TFMBDA)-O and Poly(TFMBDA)-E were synthesized via chemical oxidative and enzymatic polymerization methods, respectively, using 4-(trifluoromethyl)benzene-1,2-diamine (TFMBDA) as monomer. FT-IR, UV–vis and 1H-NMR and 13C-NMR instruments were utilized in order to confirm the structures of all compounds. The Mw values of the polymers and their PDI values were found to be between 5000–7000 Da and 1.045–1.115, respectively, from GPC measurements. The glass temperature of phenazine-type structure of Poly(TFMBDA)-O was higher compared to that of Poly(TFMBDA)-E, which was composed of phenyl units linked with –NH bridges. As soon as Poly(TFMBDA)-O and Poly(TFMBDA)-E were excited by UV light, they had a quantum efficiency of 6.3% and 13.7%, respectively, in DMF for violet photoluminescence (PL) emission depending on photoluminescence measurement. SEM images revealed that Poly(TFMBDA)-O consisted of approximately 1–2 μm of uniform micro-spheres and a granular surface with different pore diameters. The enzymatic oxidation with HRP afforded Poly(TFMBDA)-E micro-rods of about 5–10 μm-long shape in their SEM images.Öğe Investigation of electrochemical, optical, and thermal properties via oligomerization of aminophenol monomer containing halogen and nitro groups using two distinct oxidants(Elsevier, 2023) Karacan Yeldir, Elif; Kolcu, Feyza; Kaya, İsmetIn this study, two different oligomers of 2-amino-4-chloro-5-nitrophenol (ACNP) with incorporated halogen atom and nitro groups were synthesized by oxidative oligomerization method using two different oxidants, namely H2O2 and ammonium persulfate (APS). Structural characterizations of the obtained products were elucidated by 1H NMR, 13C NMR, FT-IR, UV-Vis spectroscopy methods. The molecular masses of the oligomers were deter-mined through the utilization of Gel Permeation Chromatography (GPC). The analysis revealed that the Mw values of the oligomers synthesized via the oxidative oligomerization method using H2O2 and APS, denoted as OACNP-1 and OACNP-2 were 4150 Da and 2800 Da, respectively. Using the UV-vis spectrophotometer, the optical band gaps were calculated as 2.64 eV, 1.95 eV and 2.14 eV for ACNP, OACNP-1 and OACNP-2, respectively. Thermal properties of the oligomers were investigated using Thermal Gravimetric Analysis-Differential Thermal Analysis (TGA-DTA) and Differential Scanning Calorimetry (DSC). The results demon-strated that OACNP-1 exhibited significantly higher thermal stability when compared to both the monomer and OACNP-2. In addition, Fluorescence Spectroscopic analysis of the oligomers revealed that OACNP-1 emitted blue light at 440 nm when excited with light of a wavelength of 370 nm, exhibiting fluorescent characteristics. Furthermore, the surface properties and morphologies of the oligomers were analyzed with the help of Scanning Electron Microscopy (SEM), revealing a flower-like structure for the oxidative oligomerization product, OACNP-1, in the presence of H2O2. In course of a change in the oxidant, the oligomer, OACNP-2, had rough and spongy surface morphology with some pores.Öğe Investigation of horseradish peroxide and hydrogen peroxide mediated synthesis of amino-functional oligomers: Characterization and fluorescence study(Elsevier, 2021) Kolcu, Feyza; Kaya, İsmetThe insightful mechanism of two oligomerization methods using either horseradish peroxide (HRP)/hydrogen peroxide (H2O2) (enzymatic approach), or H2O2 (35% aqueous) (chemical approach) on 4-phenoxy aniline (PA) and 4-(4-chlorophenoxy)aniline (PACl) as two amino-functional monomers was studied. Four oligomers syn- thesized were described by FT-IR, UV-Vis, 1H-NMR and 13C-NMR techniques for the molecular structure analysis. The oligomers substituted with chlorine had stronger electron acceptor ability, which enhanced the intra- molecular charge transfer between the donating moiety and chlorine acceptor substituent, resulting in a 48 nm red shift of the λmax for the n→π* electronic transition. Oligomers prepared by horseradish peroxidase shows better fluorescence properties than the monomers. The use of oxidoreductase enzyme (HRP) as the catalyst, for the one-step oligomerization of the monomers demonstrated to yield fluorescent products. Photoluminescence (PL) measurements enlightened that emission quantum yields of PACl-E in DMF were found to be 18% and 4.2% at the maximum emission wavelength of 412 nm and 482 nm, respectively. it is considered as green oligo- merization/polymerization method Since HRP catalysis provided a green oxidative oligomerization method of aniline and their derivatives, four oligomers were produced by peroxidase-catalyzed oxidation oligomerization in relation to their electronic properties. HOMO-LUMO energy levels were calculated to make comments about electrochemical (E′ g) band gaps of the oligomers which were lower than those of their regarding monomers. SEM images were provided to study the morphology of the oligomers. Intermolecular dihydrophenazine formation in the course of enzymatic oligomerization would eventuate in highly ordered structures.Öğe Oligomerization of dibrominated aminophenol on the basis of the chemical and HRP-catalyzed oxidative processes: Characterization and photoluminescence properties(Elsevier Sci Ltd, 2024) Kolcu, Feyza; Kaya, İsmetPreparation of oligo (aminophenols) was carried out by chemical oxidative and enzymatic oligomerization of 4amino-2,6-dibromophenol (ADBP). The former method required hydrogen peroxide as catalyst in an aqueous sodium hydroxide solution and the latter method was catalyzed by an enzyme, horseradish peroxidase, in 1,4dioxane resulting in the formation of (ADBP)-ox and (ADBP)-enz, respectively. For the structural confirmation for both of the synthesized oligomers were fulfilled using FT-IR, UV - vis and 1 H NMR and 13 C NMR instruments. The chemical oxidation with H 2 O 2 induced monodisperse particles in the sub-micron size. The thermal treatment of the oligomers at 1000 omicron C showed that the chemical oxidation resulted in (ADBP)-ox with higher residue% compared to enzymatic oxidation. Neutral ADBP underwent facile oxidation, leading to the formation of its corresponding oligomers, which were composed of head-to-tail or ortho -coupled constitutional moieties with lower optical and electrochemical band gaps than those of ADBP using two oligomerization routes. By analyzing the solvent effect on the absorption, lower optical band gaps of the synthesized oligomers were obtained in some selected solvents, pointing out them as semi-conductive material for the production of optoelectronic and electronic materials. By tuning the excitation wavelength, the fluorescence intensity of both of the oligomers was changed. DMF solution of (ADBP)-ox and (ADBP)-enz had a quantum yield of 17.6 % and 1.2 % for green and orange photoluminescence emission, respectively, with excellent photostability.Öğe Poly(azomethine)s Anchored by Cresol and Pyrrole Units: Synthesis, Characterization and Spectroscopy Studies(Polymer Soc Korea, 2019) Kaya, İsmet; Kolcu, Feyza; Tasvir Arıcı, Gizem; Çölekoğlu, EzgiIn this study, poly(azomethine)s with cresol and pyrrole as side chain units were synthesized in three steps. In the first step; symmetrical dialdehyde bromide (DAB), in the second step; symmetrical derivatives (DAB-1 and DAB-2) of DAB using p-cresol and pyrrole, respectively, and in the third step; poly(azomethinecresol) (P-1) and poly(azomethine-pyrrole) (P-2) were obtained via condensation reaction. Structures of all synthesized compounds were confirmed by FT-IR, UV-Vis, and H-1 NMR spectroscopic analyses. Photophysical and electrochemical properties of these compounds were investigated using photoluminescence (PL) and cyclic voltammetry (CV) measurements, respectively. Based on photoluminescence analysis, the multicolor properties of DAB-2, P-1 and P-2 were observed in DMF solution. Additionally, results of thermal studies of TG-DTA and DSC techniques showed they were thermally stable compounds.Öğe Poly(azomethine-epoxy-ether) containing phenyl and etoxy moieties: synthesis, characterization and fluorescence property(Springer International Publishing Ag, 2018) Kolcu, Feyza; Kaya, İsmetThe design and synthesis of poly(azomethine-epoxy-ether) (PAZ-EP) containing epoxide moiety was described. The purpose of the research was the improvement of poly(azomethine-ether) containing epoxide by introduction of Schiff base moiety. PAZ-EP was synthesized using epichlorohydrin (EP). The structure of the Schiff base (SB) and PAZ-EP were verified by FT-IR, H-1-NMR, C-13-NMR and UV-Vis spectroscopic analyses. Further characterization was employed using photophysical, electrochemical and fluorescence (PL) measurements. Application of TGA and differential scanning calorimetry analyses revealed thermal stability and thus propose a thermal processibility, which makes them potential materials for many contemporary practices. The number of average molecular weight of polymer with a polydispersity index of 1.14 was found to be 6750 Da using a gel permeation chromatography instrument. The highest occupied-lowest unoccupied energy levels and electrochemical () band gap values of PAZ-EP were determined by cyclic voltammetry (CV) measurement. Scanning electron microscopy (SEM) images were illustrated at different magnifications to study the morphologic property of PAZ-EP.Öğe Poly(azomethine-epoxy-ether) containing phenyl and etoxy moieties:synthesis, characterization and fluorescence property (vol 72, pg 2821, 2018)(Springer International Publishing Ag, 2020) Kolcu, Feyza; Kaya, İsmet[Anstract Not Available]Öğe Polymerization of Chrysoidine with chemical and enzymatic oxidative preference: Synthesis, characterization, and spectroscopic study(Wiley, 2018) Kaya, İsmet; Kolcu, FeyzaChrysoidine (CHRY) is a type of azo-dye extensively used in industry. This study delineates 2 routes as enzymatically and oxidatively polycondensation of chrysoidine for the syntheses of poly (chry-enz) and poly (chry-ox), respectively. The molecular structures of enzymatically and oxidatively polymerized chrysoidine were described by the FT-IR, UV-Vis, H-1-NMR, and C-13-NMR techniques. The molecular structures were obtained to be different as in the cyclization process of the enzymatic polymerization. Solvatochromic behavior in selected polar solvents on the optical properties of poly (chry-ox) were studied. Further characterization was implemented by fluorescence (PL), electrochemical, thermogravimetric (TG-DTA), cyclic voltammetry (CV), and differential scanning calorimetry (DSC) measurements. The number of average molecular weight of poly(chry-ox) was found to be higher than that of poly(chry-enz). Photoluminescence (PL) measurements enlightened the response of poly (chry-ox) with intense light emissions upon a bicolor irradiation by Ultra-Violet and visible light. CV technique was utilized to make a comment about HOMO-LUMO energy levels and electrochemical (Eg') band gaps of the polymers. Optical and electrochemical band gaps of poly (chry-enz) were lower than those of poly (chry-ox), proving the successful synthesis of -conjugated structure of poly (chry-enz). To further make comments about the features of the polymers, scanning electron microscopy (SEM) images were exemplified to study the surface forms of the polymers. Surface morphology of poly (chry-enz) was seen as agglomerates of grains toward the out-of-plane direction. As the polymerization method was changed, the morphology was transformed into a flat-smooth surface present with visible holes for poly (chry-ox).
