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Annealing effects of photoanode on dye sensitized solar cell performance
(Taylor & Francis Ltd, 2021) Ozkacar, Tugce; Taran, Songul; Gokcen, Muharrem; Orhan, Ersin
Photoanode annealing effects on dye sensitized solar cell (DSSC) performance were investigated. Four different temperatures (300, 400, 500 and 600 degrees C) were used to annealing of the photoanodes. Morphologic properties of the photoanodes were investigated by a field emission scanning electron microscope (FESEM) and atomic force microscope (AFM). The photovoltaic properties of these DSSCs were obtained for these temperatures using a solar simulator for two different type electrolyte with different redox concentration and additive. Also, the series and charge transfer resistances were obtained from the electrochemical impedance spectroscopy (EIS) Nyquist plots of DSSCs.
Bisbenzimidazol Bağlayıcı İçeren Biyolojik Aktif Aren Rutenyum Bileşiğinin Sentezi ve Termal Bozunmasının Belirlenmesi
(2019) Öksüz, Nilüfer; Orhan, Ersin
Bu çalışmada [Ru4(p-cymene)4(?2-N?N)2(?4-OO?OO)2][CF3SO3)4] (N?N = Bütilen-1,4-bisbenzimidazol(bbim)) genel formülüne sahip biyolojik aktif tetranükleer aren rutenyum kompleks bileşiği, Ru2(p-cymene)2 (?4-OO?OO)Cl2 (OO?OO = 5,8-dioxido-1,4-naphtoquinonato (donq))'nun gümüş triflorometansülfonat ilereaksiyona sokulması, ardından karşılık gelen N?N bağlayıcılarının eklenmesi ile hazırlanmıştır. Biyolojik aktifaren rutenyum bileşiği IR, UV-VIS, 1H, 13C NMR spektroskopisi ve ESI-MS spektrometresi dahil standarttekniklerle karakterize edildi. Aren rutenyum bileşiğinin termal bozunma ölçüm verileri incelendi. Bu ölçümlerTermogravimetrik analiz (TGA) ve Diferansiyel termal analiz (DTA) teknikleri ile yapıldı.
Biyoaktif Yeni Benzimidazol Aren Rutenyum Organometalik Bileşiğinin Sentezi ve Karakterizasyonu
(2020) Uluçay, Enes Hakkı; Orhan, Ersin
Bu çalışmada [(?6-p-simen)Ru(L2)Cl]CI genel formülüne sahip olan biyoaktif benzimidazol aren rutenyumorganometalik bileşiği, salisilaldehitin 2-(aminometil)benzimidazol dihidroklorür(ambm2.2HCI) bileşiği ilereaksiyona sokulmasının ardından, [Ru(p-simen)klorür]2 eklenmesi ile hazırlandı. Biyoaktif benzimidazol arenrutenyum organometalik bileşiği UV-VIS, IR, ESI-MS, 1H NMR,13C NMR spektroskopisi teknikleriylekarakterize edildi. Bileşiğin, Diferansiyel termal analiz (DTA) ve Termogravimetrik analiz (TGA) teknikleri ileölçümleri yapıldı, ölçüm verileri incelendi.
A catalytic regioselective procedure for the synthesis of aryl oximes in the presence of palladium nanoparticles
(Taylor & Francis Inc, 2022) Demir, Emine; Orhan, Ersin; Göksu, Haydar
The synthesis of aryl oximes from aryl aldehyde derivatives was carried out using hydroxylamine hydrochloride and aluminum oxy hydroxide-supported palladium (Pd/AlO(OH) nanoparticles. The procedure is revealed via the regioselective synthesis of oxime derivatives in a polar solvent mixture resulting in high yields at room temperature.
Coordination-driven self-assembly of arene ruthenium metalla-rectangles
(Elsevier Science Sa, 2017) Orhan, Ersin; Garci, Amine; Therrien, Bruno
Series of tetranuclear arene ruthenium complexes of the general formula [Ru-4(p-cymene)(4)(mu(2)-N boolean AND N)(2) (mu(4)-OO boolean AND OO2][CF3SO3](4) (N boolean AND N = 2,5- dipyridyl-thiophene (dptp), 3,6-dipyridyl-1,2,4,5-tetrazine (dptz), 3,6-dipyridyl-1,4-dihydro-1,2,4,5-tetrazine (dpdt)) were prepared by reacting the dinuclear arene ruthenium complexes Ru-2(p-cymene)(2)(mu(4)-OO boolean AND OO)Cl-2 (OO boolean AND OO = oxalato (oxa), 2,5-dioxido-1,4-benzoquinonato (dobq), 2,5-dichloro-1,4-benzoquinonato (dClbq), 2,5-dioxido-3-undecyl-1,4-benzoquinonato (dubq), 5,8-dioxido-1,4-naphtoquinonato (donq)) with silver trifluoromethanesulfonate, followed by the addition of the corresponding N boolean AND N linkers. All metalla-rectangles were characterized by standard techniques, including infrared, UV-visible, H-1, C-13 NMR spectroscopy and ESI mass spectrometry: Thus confirming the rectangular structure of the complexes, and showing the facility of forming tetranuclear arene ruthenium metalla-rectangles. (C) 2017 Elsevier B. V. All rights reserved.
Cytotoxic double arene ruthenium metalla-cycles that overcome cisplatin resistance
(Elsevier Science Sa, 2016) Orhan, Ersin; Garci, Amine; Riedel, Tina; Soudani, Mylene; Dyson, Paul J.; Therrien, Bruno
Tetranuclear arene ruthenium complexes of the general formula [{Ru-2(p-cymene)(2)(mu(4)-L)}(2)(mu(4)-tpom)](4+) (tpom = tetrakis(4-pyridyloxymethylene)methane) were obtained from the corresponding dinuclear arene ruthenium complexes [Ru-2(p-cymene)(2)(m(4)-L)Cl-2] (L = diethyl-1,2-diazenedicarboxylato (dadc), oxalato (oxa), bis(2-hydroxyethyl)oxamidato (bho), bis{2-(2-hydroxyethoxy)ethyl}ethanediamidato (bhe), 2,5-dioxido-1,4-benzoquinonato (dobq), 2,5-dihydroxy-3-phenyl-1,4-benzoquinonato (dhpb), 2,5-dibromo-1,4-benzoquinonato (dBrbq), 2,5-dioxido-3-undecyl-1,4-benzoquinonato (dubq), 2,5-dihydroxy-3,6-diphenyl-1,4-benzoquinonato (dhdb), 2,5-dihydroxy-3,6-(3,5-dimethylphenyl)-1,4-benzoquinonato (dhdm), 5,8-dioxido-1,4-naphtoquinonato (donq)) by reaction with the tetradentate tpom ligand and silver trifluoromethanesulfonate. The antiproliferative activity of the tetranuclear complexes was evaluated on cancerous (A2780 and A2780cisR) and non-cancerous (HEK293) cell lines, showing in most cases cancer cell selectivity and, in some cases, low micromolar cytotoxicities (similar to 1 mu M) against a cancer cell line that has acquired resistance to cisplatin. (C) 2015 Elsevier B.V. All rights reserved.
Cytotoxicity of arene ruthenium metalla-rectangles incorporating bis-pyridyl diimide linkers
(Elsevier Science Sa, 2016) Orhan, Ersin; Garci, Amine; Riedel, Tina; Dyson, Paul J.; Therrien, Bruno
A series of tetranuclear arene ruthenium complexes of the general formula [Ru-4(p-cymene)(4)(mu(2)-L)(2)(mu(4)-OO boolean AND OO)(2)][CF3SO3](4) (L-1 = N,N'-bis(4-pyridylmethyl)-pyromellitic diimide, L-2 = N,N'-bis(4-pyridylmethyl)-naphthalene diimide) were obtained from the corresponding dinuclear arene ruthenium complexes Ru-2(p-cymene)(2)(mu 4-OO boolean AND OO)Cl-2 (OO boolean AND OO = oxalato (oxa), 2,5-dioxido-1,4-benzoquinonato (dobq), 2,5-dihydroxy-3-phenyl-1,4-benzoquinonato (dhpb), 2,5-dichloro-1,4-benzoquinonato (dClbq), 2,5-dioxido-3-undecyl-1,4-benzoquinonato (dubq), 2,5-dihydroxy-3,6-diphenyl-1,4-benzoquinonato (dhdb), 5,8-dioxido-1,4-naphtoquinonato (donq)) by reaction with the bidentate ligands (L-1 and L-2) and silver trifluoromethanesulfonate. The antiproliferative activity of the tetranuclear arene ruthenium metalla-rectangles was evaluated on cancerous (A2780 and A2780cisR) and non-cancerous (HEK293) cell lines, showing in all cases cancer cell selectivity. In general, the metalla-rectangles obtained with L-2 are more potent than those incorporating L-1, and with the exception of [Ru-4(p-cymene)(4)(mu(2)-L-1)(2)(m(4)-dClbq)(2)][CF3SO3](4), they are all more active than cisplatin on the cisplatin resistant A2780cisR cell line. (C) 2016 Elsevier B.V. All rights reserved.
Effect of the photoanode fabrication condition, electrolyte type and illumination type on dye-sensitized solar cells performance
(Indian Acad Sciences, 2021) Orhan, Ersin; Gokcen, Muharrem; Taran, Songul
The combination of the photoanode fabrication condition, electrolyte type and light source effect on dye-sensitized solar cell (DSSC) performance were investigated. Three different photoanodes (C-1, C-2 and C-3) were used with different fabrication conditions with two different redox concentration electrolytes (30 and 50 mM) for each photoanode. For these six different combinations, DSSC performances were obtained for 12 different situations using two different light sources, AM 1.5 simulated and ultraviolet (UV-365 nm) illumination. It was obtained that the HI30 electrolyte has higher efficiency for UV illumination and the AN50 electrolyte has higher efficiency for AM1.5 simulated illumination. It was also obtained that the C-2 cell with double layer immersed in dye solution has higher efficiency for both two illumination types and two electrolytes.
Electrical property investigation of the Au/n-Si and Au/PVA plus benzimidazole Co complex/n-Si diodes under ultraviolet illumination
(Springer, 2021) Gokcen, Muharrem; Taran, Songul; Orhan, Ersin
Polyvinyl alcohol (PVA) was doped using the di[1-(2-ethoxyethyl)-5-nitrobenzimidazole] cobalt dichloride and this polymeric composite was used as an interface in Au/n-Si diodes. The basic electrical properties of these fabricated Au/n-Si (MS) and Au/PVA+Co complex/n-Si (MPS) diodes were examined measuring voltage-dependent current (I(V)) data in various ultraviolet illumination intensities and room temperature. Electrical parameters of the MS and MPS diodes were calculated by thermionic emission, Norde, and Card & Rhoderick method. It was found that the ideality factor (n) values of the MS diode increased from 6.7 to 13.4 while the MPS ones increased from 3.4 to 7.5 with increasing illumination. Also, the photo-responsivity (PR) of MPS diode was obtained for P = 50 mW/cm(2) (365 nm UV) as 0.29 A/W at - 5.00 V and 4.01 mA/W at 0 V.
Fabrication and photoanode performance of ZnO nanoflowers in ZnO-based dye-sensitized solar cells
(Elsevier, 2022) Biçer, Mustafa; Gokcen, Muharrem; Orhan, Ersin
ZnO photoanodes consisting of nanoflowers were successfully synthesized on FTO substrates in two steps using the seed layer-hydrothermal method. To control the morphological and photovoltaic properties of ZnO thin films, three types of photoanodes were fabricated in the presence of NH3 (C1), NH3-PEG (C2) and NH3-PVA (C3). The morphological and structural properties of the produced photoanodes were investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). Using these photoanodes, six different types of dye sensitized solar cell (DSSC) were obtained with Ruthenium Dye (Z907) and two different electrolytes. Photovoltaic (PV) and electrochemical impedance spectroscopy (EIS) characterization of DSSCs were performed. The maximum energy conversion efficiencies of these photoanodes in the presence of NH3, NH3-PEG and NH3-PVA were obtained as 1.57, 0.70 and 1.61, respectively, for the same type of electrolyte (AN50) under 100 mW/cm2 illumination.
Flexible arene ruthenium metalla-prisms
(Elsevier Science Sa, 2015) Orhan, Ersin; Garci, Amine; Therrien, Bruno
Cationic arene ruthenium metalla-prisms of the general formula [Ru-6(p-cymene)(6)(tpmtt)(2)(OO boolean AND OO)(3)](6+) (tpmtt = 1,3,5-tris(pyridin-4-ylmethyl)-1,3,5-triazinane-2,4,6-trione) have been obtained from the corresponding dinuclear arene ruthenium complexes [Ru-2(p-cymene)(2)(OO boolean AND OO)Cl-2] (OO boolean AND OO = oxalato (ox), 2,5-dioxido-1,4-benzoquinonato (dobq), 2,5-dichloro-1,4-benzoquinonato (dClbq), 2,5-dioxido-3-undecyl-1,4-benzoquinonato (dubq), 5,8-dioxido-1,4-naphtoquinonato (donq)) by reaction with the tridentate tpmtt ligand and silver trifluoromethanesulfonate. These cationic arene ruthenium metalla-prisms have been isolated and characterized as their triflate salts. Upon formation of the metalla-prisms, the two tpmtt panels are in close proximity and do not allow encapsulation of guest molecules. (C) 2015 Elsevier B.V. All rights reserved.
High photo-responsivity Au/polyvinyl alcohol (PVA)+di[1-(2-ethoxyethyl)-5-nitrobenzimidazole] copper dichloride/n-Si UV photodiode
(Elsevier Science Sa, 2020) Gokcen, Muharrem; Orhan, Ersin; Taran, Songul
Au/n-Si metal/semiconductor (MS) type diode was transformed into a metal/polymer/semiconductor (MPS) type diode by polyvinyl alcohol (PVA)+benzimidazole Cu complex interfacial layer to achieve better photodiode properties. Au/PVA + benzimidazole Cu complex/n-Si MPS diode's electronic and photo-responsivity (PR) properties were investigated by current-voltage (I-V) measurements under various ultraviolet (UV) (365 nm wavelength) illumination intensities (from 50 to 250 mW/cm(2)) and at room temperature. It was found that the difference between the dark and high UV illumination I(V) plots of the MPS diode exceeds 10(5) times. Thus, this higher response to UV illumination has caused the reverse region current of the diode exceeds the forward region current since the first UV illumination level (50 mW/cm(2)). This ensures both the MPS diode has a very high PR value and allows that the diode working direction can be adjusted with UV exposure. The remarkably high PR values were obtained for P = 100 mW/cm(2) as 11.01 A/W at -4.84 V, and 2.14 mA/W at 0 V. Also, main electronic parameters of the MPS diode were calculated by thermionic emission, Ohm law, Cheung&Cheung and Card&Rhoderick methods. The series resistance (Rs) values calculated for each Cheung&Cheung function are compatible each other and there is an acceptable coherence with obtained values by ohmic approach. For the surface states density (N-ss) of the MPS diode obtained for each UV illumination, it was found that they are higher than the dark ones and they shifted to lower energy region. (c) 2020 Elsevier B.V. All rights reserved.
Investigation of photochromic fluorescence features and synthesis of diarylethene type naphthalimide compounds
(Turkish Chemical Society, 2020) Orhan, Ersin; Narin, Mustafa
The aim of the study was to synthesise novel photo-exchangeable photochromic fluorescent compounds. 3,4-Bis(3,5-dimethyl-4-pyrazolyl)-N-butyl-1,8-naphthalimide 6 and 3,4-bis (1,3,5-trimethyl-4-pyrazolyl)-N-butyl-1,8-naphthalimide 7 naphthalimide derivative new compounds were prepared via two-step Suzuki coupling reaction of pyrazolylboronic acid esters from N-butyl-4-bromo-3-iodo-1,8-naphthalimide and characterized by1H-NMR,13C-NMR, MS and FTIR. Their photochromic fluorescence properties were investigated. Additionally, a solvent effect on the fluorescent properties of 6 and 7 was investigated. Increase of organic solvent polarity results in a red shift (to longer wavelengths) of the fluorescence emissions. © 2020, Turkish Chemical Society. All rights reserved.
A Novel Benzimidazole-Based Chemosensor for Fluorometric Determination of Zinc Ions
(Springer/Plenum Publishers, 2021) Orhan, Ersin; Ergun, Ece; Sarkaya, Koray; Ergun, Umit
A simple and novel Schiff base chemosensor (BMHM) based on benzimidazole was synthesized. In ethanol-water (1:1, v/v) medium on varying concentrations of Zn2+ chemosensor exhibited a strong and quick turn on fluorescence response. The Zn2+ recognition was based on the Chelation-enhanced fluorescence effect. The binding constant and limit of detection for BMHM-Zn2+ complexation were estimated to be 7.99 x 104 M-1 and 0.148 mu M, respectively. The extreme fluorescent enhancement caused by Zn2+ binding in chemosensor BMHM occurred at a pH range of 6-7. The practical use of chemosensor BMHM was tested by determination of Zn2+ in real water samples and comparing the results with the data obtained using high resolution inductively coupled plasma mass spectrometry.
Performance analysis and negative dielectric anisotropy behavior of nematic liquid crystal doped with newly synthesized 1-(p-chlorobenzyl)-5-nitrobenzimidazole cobalt complex
(Elsevier Science Sa, 2018) Orhan, Ersin; Gökçen, Muharrem; Köysal, Oğuz
The study investigates electrical current and dielectric properties of liquid crystal (LC) mediums. The studied samples are pure E63 and di[1-(p-chlorobenzyl)-5-nitrobenzimidazole] cobalt dichloride doped E63.The combination of 1-(p-chlorobenzyl)-5-nitrobenzimidazole (1) with metal salt (CoCl2 center dot 6H(2)O) was prepared stable solid new di[1-(p-chlorobenzyl)-5-nitrobenzimidazole] cobalt dichloride (2). Synthesized di[1-(p-chlorobenzyl)-5-nitrobenzimidazole] cobalt dichloride was identified by H-1 NMR spectroscopic technique and elemental analysis. Frequency dependence of the dielectric properties and dielectric anisotropy of LC sampleswas investigated using the admittance spectroscopy method (C-V and G/omega-V) in the frequency range of 100 Hz-10 MHz at room temperature. E63 coded nematic crystal was used as pure liquid crystal. The doping material concentration is ensured 1 wt % in E63. Dielectric constant (epsilon'), dielectric loss (epsilon") dielectric loss tangent (tan delta) and real and imaginary parts of electrical modulus (M'and M") of the LC samples calculated. Also, dielectric anisotropy (Delta epsilon) versus frequency plots were obtained for both samples.
Photophysics, pH sensing, and hydrolysis study of a novel 1,8-naphthalimide derivative
(Turkish Chemical Society, 2018) Atahan, Alparslan; Orhan, Ersin
In this study, a novel highly emissive compound was synthesized via a two-step synthetic procedure and characterized by1H-NMR,13C-NMR and FTIR. Then its photophysical properties, pH sensing behaviors and pH-dependent hydrolysis were systematically investigated by ultraviolet and fluorescence spectroscopy. Photophysics studies were carried out in fourteen common organic solvents and absorption/emission spectra were recorded in Britton Robinson buffers (pH=3-12) to determine pH sensing behaviors. From the photophysical results, it has been shown that the novel compound exhibits strongly solvent polarity dependent emission and has high quantum yield (up to 0.72). Furthermore, at pH=12, absorbance started to decrease while emission was increasing and blue-shifting due to basic hydrolysis after a several minutes. Therefore, time dependent hydrolysis was also investigated at mentioned pH. © 2018, Turkish Chemical Society. All rights reserved.
Preparation and photochromic properties of 2,3-bisarylbenz[f]indenones
(Elsevier Science Sa, 2013) Köse, Mahmut; Orhan, Ersin; Suzuki, Kazushi; Tutar, Ahmet; Ünlü, Cihansel Sancak; Yokoyama, Yasushi
From 2,3-dibromobenz[f]indenone, four compound: 2,3-bis(5-methyl-2-phenyl-4-thiazolyl)benz [f]indenone 10, 2,3-bis(3,5-dimethyl-4-isoxazolyl)benz[f]indenone 20, 3-(3,5-dimethyl-4-isoxazolyl)-2-(5-methyl-2-phenyl-4-thiazolyl)benz[f]indenone 30 and 2,3-bis(5-methyl-2-phenyl-4-thiazolyl)benz[f]indenol 40 were prepared, and their photochromic properties were investigated. Among them, photochrome 10 (weak photochromic) and its bisthiazolylbenz[f]indenol derivative 40 displayed photochromism. During ring closure photoreaction, photochrome 40 showed high conversion ratio (98.4%) with low diastereomeric excess (38%). (C) 2013 Elsevier B.V. All rights reserved.
Synthesis and characterization of novel benzimidazole cobalt and copper complexes and applying in Au/PVA/n-Si diode
(Elsevier, 2020) Gokcen, Muharrem; Orhan, Ersin; Taran, Songul
A new stable solid di[1-(2-ethoxyethyl)-5-nitrobenzimidazole] cobalt dichloride (2) and di[1-(2-ethoxyethyl)-5nitrobenzimidazole] copper dichloride (3) were prepared by the combination of 1-(2-ethoxyethyl)-5-nitrobenzimidazole (1) with metal salts (CoCl2 center dot 6H(2)O and CuCl2 center dot H2O). Synthesized di[1-(2-ethoxyethyl)-5-nitrobenzimidazole] cobalt dichloride (2) and di[1-(2-ethoxyethyl)-5-nitrobenzimidazole] copper dichloride (3) were identified by H-1 NMR and C-13 NMR spectroscopic techniques and elemental analysis. Poly vinyl alcohol (PVA) polymer with and without novel benzimidazole cobalt and copper complexes dopant interfacial layers were used in Au/n-Si diodes. The basic electrical properties of these fabricated four diodes were examined using currentvoltage (I-V) measurements in dark and room temperature. The n and I0 values of all MPS diodes are smaller than the MS diode and the Phi(B0) values are greater.
Synthesis and Characterization of Some New 4-Methyl-5-Imidazole Carbaldehyde Derivatives
(2019) Orhan, Ersin; Köse, Mahmut; Alkan, Demet; Öztürk, Leyla
Imidazole is a common and important heterocyclic fragment of many biologically importantmolecules. 5-imidazole-carbaldehydes containing mono- (N-1) methyl (or aryl) analogs are commonlyused as building blocks in medical chemistry. In this study, starting from 4-methyl-1H-imidazole-5-carbaldehyde, the N-1 atom of the imidazole ring is derived with different alkyl groups. In addition,both N atoms of the starting imidazole-carbaldehyde were methylated to give 5-carbaldehyde-1,3,4-trimethyl-3-imidazolium salt. The salt which possess quite reactive carbaldehyde group could be usedas a precursor for synthesis of other imidazolium derivatives. Furthermore, 4-methyl-5-imidazolecarbaldehyde was converted into the benzoxazole, benzothiazole and benzoimidazole by a two-stepreaction over the aldehyde group. These new compounds could display some biological activities.
Synthesis and photochromic properties of 4,5-bisaryl-3(2H)-pyridazinones
(Elsevier Science Sa, 2016) Orhan, Ersin; Gündoğdu, Leyla; Köse, Mahmut; Yokoyama, Yasushi
Six novel photochromic bisarylpyridazinones containing 2,5-dimethylthiophene or 5-methy1-2-phenylthiazole unit were synthesized, and their photochromic and fluorescence properties were investigated. The bisarylpyridazinones underwent reversible color change upon irradiation with UV or visible light. The effect of solvents on the absorption spectra of the bisarylpyridazinones was investigated. The closed-ring forms of bisarylpyridazinones displayed negative solvatochromism which was attributed to the high dipolar characters of the molecule. The open-ring forms of bisarylpyridazinones showed fluorescence at 400-480 nm upon excitation at 302 nm, and the intensities of emission bands gradually decreased during the ring-closing photoreactions. Among the synthesized bisarylpyridazinones, 4,5-bis(5-methyl-2-phenylthiazol-4-yl)-2-methyl(or 2-phenyl) pyridazin-3(2H)-ones (50 and 60) displayed rather large absorption and emission spectral change, higher quantum efficiency during the photoreaction compared to others. A high conversion ratio (94%) to the closed form was observed for 50. (C) 2015 Elsevier B.V. All rights reserved.

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