Person: GÖRK, GÜLŞEN
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Last Name
GÖRK
First Name
GÜLŞEN
Name
5 results
Search Results
Now showing 1 - 5 of 5
Publication Metadata only Synthesis and characterization of the novel 4-(1-(pyridin-4-yl) ethoxyl) substituted bis(phthalocyaninato) rare earth complexes and investigation of their two-photon absorption-based third-order non-linear optical properties(ELSEVIER, 2022) GÖRK, GÜLŞEN; Cavus, Aleyna; Gork, Gulsen; Erdem, Murat; Ozer, MetinNovel 4-(1-(pyridin-4-yl) ethoxyl) substituted double-decker rare earth phthalocyanine complexes were synthesized starting from (R)-4-(1-(pyridin-4-yl) ethoxy) phthalonitrile with proper rare earth metal acetates in octanol catalyzed by 1,8-diazabicyclo[5.4.0]undec-7-ene at 300 degrees C. The new starting phthalonitrile compound was obtained from (R)-1-(pyridin-4-yl) ethan-1-ol and 4-nitrophthalonitrile in acetonitrile at reflux temperature in the presence of potassium carbonate as a catalyst. The characterization of the synthesized and isolated compounds was performed by elemental analysis, infrared, ultraviolet visible, proton and correlation spectroscopy nuclear magnetic resonance, and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopic methods. Nonlinear optical responses of all complexes are investigated using the Z-scan method. The nonlinear absorption coefficient, two-photon absorption cross-section, and the imaginary part of the nonlinear susceptibility of complexes are calculated for each discrete concentration. All these nonlinear parameters of our rare-earth coordinated doubledecker phthalocyanines present a decrement due to the aggregation under high optic powers, which result in sequential two-photon absorption for smaller ionic radii. (c) 2021 Elsevier B.V. All rights reserved.Publication Metadata only Nonlinear optical behavior and optical power limiting characteristics of peripheral symmetrical and non-symmetrical zinc phthalocyanines with nanosecond pulsed excitation(PERGAMON-ELSEVIER SCIENCE LTD, 2021) GÖRK, GÜLŞEN; Erdem, Murat; Korkmaz, Eda; Kosoglu, Gulsen; Ahmetali, Erem; Farajzadeh, Nazli; Eryurek, Gonul; Kocak, Makbule BurkutIn this study, the optical nonlinear absorption and optical limiting performances of symmetrical and non-symmetrical zinc phthalocyanines in tetrahydrofuran (THF) solution were conducted by the open aperture z-scanning technique. A new non-symmetrically substituted metallophthalocyanine, namely 2(3)-[(4- nitrophenyl)ethynyl]-{9(10),16(17),23(24)-tris-(3,5-bis(trifluoromethyl)phenoxy)-phthalocyani-nato}zinc(II) (1b), was synthesized and then characterized by applying different spectroscopic methods, such as FT-IR, H-1 NMR and MALDI-TOF spectroscopy. According to the literature, {2(3),9(10),16(17),23(24)-tetrakis-(3,5-bis(trifluoromethyl)phenoxy)-phthalocyaninatolzin(II) (1a), {2,3,9,10,16,17,23,24-octakis-(3,5-bis(trifluomethyl)phenoxy)-phthalocyaninato}zinc(II) (2a) and 2(3)-[(4-nitrophenyl)ethynyl]-{9,10,16,17,23,24-hexakis-(3,5-bis(trifluoromethyl)phenoxy)-phthalocyani nato}zinc(II) (2b) were prepared. The effect of the symmetry and substituent's number on the nonlinear behavior was determined. A Nd:YAG laser, nanosecond pulsed at 532 nm, was used as the excitation source. The measurements of the input-output power and the nonlinear transmission properties were carried out for different excitation power values and different concentrations of the phthalocyanines in the THF solution. The nonlinear absorption coefficient of beta and the imaginary part of the third order nonlinear susceptibility of the medium (X-3) were found to be strongly dependent on the concentration. All the zinc phthalocyanine complexes showed good optical limiting performances, attributed to a reverse saturable absorption (RSA) process. The results indicate that the zinc phythcyanine complexes are promising candidates for optical limiting materials. (C) 2020 Elsevier Ltd. All rights reserved.Publication Metadata only 3-D optical profilometry at micron scale with multi-frequency fringe projection using modified fibre optic Lloyd's mirror technique(ELSEVIER SCI LTD, 2018) GÖRK, GÜLŞEN; Inanc, Arda; Kosoglu, Gulsen; Yuksel, Heba; Inci, Mehmet NaciA new fibre optic Lloyd's mirror method is developed for extracting 3-D height distribution of various objects at the micron scale with a resolution of 4 mu m. The fibre optic assembly is elegantly integrated to an optical microscope and a CCD camera. It is demonstrated that the proposed technique is quite suitable and practical to produce an interference pattern with an adjustable frequency. By increasing the distance between the fibre and the mirror with a micrometre stage in the Lloyd's mirror assembly, the separation between the two bright fringes is lowered down to the micron scale without using any additional elements as part of the optical projection unit. A fibre optic cable, whose polymer jacket is partially stripped, and a microfluidic channel are used as test objects to extract their surface topographies. Point by point sensitivity of the method is found to be around 8 mu m, changing a couple of microns depending on the fringe frequency and the measured height. A straightforward calibration procedure for the phase to height conversion is also introduced by making use of the vertical moving stage of the optical microscope. The phase analysis of the acquired image is carried out by One Dimensional Continuous Wavelet Transform for which the chosen wavelet is the Morlet wavelet and the carrier removal of the projected fringe patterns is achieved by reference subtraction. Furthermore, flexible multi -frequency property of the proposed method allows measuring discontinuous heights where there are phase ambiguities like 2 pi by lowering the fringe frequency and eliminating the phase ambiguity. (C) 2017 Elsevier Ltd. All rights reserved.Publication Metadata only Synthesis, characterization, third-order non-linear optical properties and DFT studies of novel SUBO bridged ball-type metallophthalocyanines(ROYAL SOC CHEMISTRY, 2020) GÖRK, GÜLŞEN; Alizadeh, Shabnam; Kosoglu, Gulsen; Erdem, Murat; Acar-Selcuki, Nursel; Ozer, Metin; Salih, Bekir; Bekaroglu, OzerNovel 4,4 '-(((2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)bis(2-methylpropane-2,1-diyl))bis(oxy)) (SUBO) bridged ball-type metallophthalocyanines were synthesized starting from 4,4 '-(((2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)bis(2-methylpropane-2,1-diyl))bis(oxy))diphthalonitrile with convenient metal salts in 2-N,N-dimethylaminoethanol. A new bisphthalonitrile compound was obtained from 2,2 '-(2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl)bis(2-methylpropan-1-ol) and 4-nitrophthalonitrile in acetonitrile at reflux temperature in the presence of potassium carbonate as a catalyst. The structural characterization of the compounds was performed by elemental analysis, and infrared, ultraviolet-visible and matrix-assisted laser desorption/ionization time-of-flight mass spectroscopic methods. Nonlinear absorptions of the phthalocyanine complexes were measured using the Z-scan technique with 7 ns pulse duration at a 532 nm wavelength. It is obvious that ball-type copperphthalocyanine has a high nonlinear absorption coefficient and imaginary component of the third-order susceptibility compared to other complexes. Therefore, ball-type copperphthalocyanine can be regarded as a very good candidate for optical limiting applications. Density functional theory was used for geometry optimizations and time-dependent density functional theory calculations of electronic transitions in order to compare with the experimental results. Molecular orbital and nonlinear optical analyses were also performed with density functional theory at the CAM-B3LYP/6-31G(d,p)/LANL2DZ level. The nonlinear optical analyses show that ball-type copperphthalocyanine has significantly better nonlinear optical properties in comparison to a common reference compound, urea.Publication Metadata only Nonlinear optical properties of peripheral symmetrically and non-symmetrically 4-(trifluoromethoxy)phenoxy substituted zinc phthalocyanines(ELSEVIER SCIENCE SA, 2020) GÖRK, GÜLŞEN; Farajzadeh, Nazli; Kosoglu, Gulsen; Erdem, Murat; Eryurek, Gonul; Kocak, Makbule BurkutIn this work, new non-symmetrical, peripherally substituted metallophthalocyanines, namely 2(3)-[(4-nitrophenyeethynyl]-{9,10,16,17, 23, 24-hexakis-(4-(trifluoromethoxy)phenoxy)-phthalo cyaninato zinc (1 b) and 2(3)-[(4-nitrophenyeethynyl]-{9(10),16(17),23(24)-tris-(4-(trifluoromethoxy)phenoxy)-phthalocyaninatolzinc (2b) were prepared. Structural elucidation of the novel zinc phthalocyanines was carried out with well-known spectroscopic methods. The solubility of the phthalocyanines was investigated in organic solvents like tetra-hydrofuran, dichloromethane, and dimethyl sulfoxide. The effect of concentration on aggregation behavior of the resulting phthalocyanines (1b and 2b) was examined in a wide area ranging from 4 x 10(-6) to 14 x 10(-6) M in tetrahydrofuran. Aggregation properties of the macrocyclic molecules (1b and 2b) were also investigated in many organic solvents. Based on the data existing in the literature, peripherally octa- and tetra-substituted zinc phthalocyanines (1a and 2a) with 4-(trifluoromethoxy)phenoxy moieties were synthesized. Optical limiting and the third-order nonlinear properties of symmetrically and non-symmetrically substituted phthalocyanines were determined and compared with each other.