giray topal - Academia.edu (original) (raw)

Papers by giray topal

Biochemical Systematics and Ecology, Aug 1, 2023

Environmental progress & sustainable energy, May 23, 2023

This study investigates the synthesis and evaluation of a new polymeric adsorbent for adsorbing C... more This study investigates the synthesis and evaluation of a new polymeric adsorbent for adsorbing Cu2+ and Co2+ ions from aqueous solutions. In this study, R‐(+)‐methylbenzylamine and acryloyl chloride were used to synthesize N‐(1‐phenylethyl)‐acrylamide (PEA) monomer, and the synthesized PEA was characterized by FTIR, 1H‐NMR and 13C‐NMR. Then, using PEA, ethylene glycol dimethacrylate (EGDMA) and methyl methacrylate (MMA) monomers by radical polymerization reaction, cross‐linked poly(ethylene glycol dimethacrylate‐methyl methacrylate‐N‐(1‐phenylethyl)acrylamide) (poly(EGDMA‐co‐ MMA‐co‐PEA) copolymer was obtained. FTIR, solid‐NMR, and elemental analysis methods were used to characterize the poly(EGDMA‐co‐MMA‐co‐PEA) obtained. Poly(EGDMA‐co‐MMA)‐co‐PEA) copolymer was used as an adsorbent in the final stage of the study to remove copper (Cu2+) and cobalt (Co2+) ions from aqueous solutions. The study examined the effects of various variables including contact time, initial metal ion concentration, and pH on adsorption efficiency. The initial concentration, contact time, and solution pH that were found to be most effective for Cu2+ ion removal were 1000 mg/L, 20 min, and 6, respectively. The ideal working parameters for Co2+ removal were determined to be an initial concentration of 1000 mg/L, a contact period of 50 min, and a solution with a pH of 6. While the adsorption capacity of Cu2+ was 185.44 mg/g at 25°C, the adsorption capacity of Co2+ was 123.76 mg/g under the same conditions. The kinetic data were best described by the theoretical adsorption capacity, which was close to the experimentally determined value for the adsorption of Cu2+ and Co2+ ions, and the pseudo‐second‐order with the highest regression coefficient.

Journal of Heterocyclic Chemistry, 2001

This study represents a facile synthesis of building blocks (1–3) of crown ethers and amine preco... more This study represents a facile synthesis of building blocks (1–3) of crown ethers and amine precoursers (4a‐d). The study also involves synthesis of mono and dibenzo N, N‐disubstituted diaza 18‐crown‐6 derivatives with high yield without chromatographic purification and high vacuum distillation. The complex ability of host the ethers was evaluated in terms of structural modification.

Bioorganic & Medicinal Chemistry Letters, Sep 1, 2011

Discovery of GR inhibitors has become very popular recently due to antimalarial and anticancer ac... more Discovery of GR inhibitors has become very popular recently due to antimalarial and anticancer activities. In this study, the synthesis and GR inhibitory capacities of novel nitroaromatic compounds (NCs) (1-3) were reported. Some commercially available molecules were also tested for comparison reasons. The novel NCs were obtained in high yields using simple chemical procedures and exhibited much potent inhibitory activities against GR at low micromolar concentrations with K(i) values ranging from 0.211 to 4.57 μM as compared with well-known agents. Inhibition mechanism was assessed as being due to occlusion of the active site entrance by means of the NCs. Molecular docking results have shown that docking poses of ligands are able to construct binding interactions with the essential amino acids.

Journal of Chemistry, 2013

Firstly, chitin derivatives were synthesized. For this purpose, chitin was modi�ed via ring-openi... more Firstly, chitin derivatives were synthesized. For this purpose, chitin was modi�ed via ring-opening reaction with cyclic anhydrides in lithium chloride/N,N-dimethylacetamide. en, chitin derivatives synthesized were characterized by FTIR, 1 H NMR, 13 C NMR, and U-Vis spectroscopies and scanning electron microscopy. ermogravimetric analysis was performed to investigate the thermal stability of chitin derivatives. ermogravimetric analysis results showed that chitin modi�ed with trimellitic anhydride is thermally more stable than chitin modi�ed with phthalic anhydride. In addition, the electrical conductivity of chitin modi�ed with phthalic anhydride and trimellitic anhydride was also measured. Electrical conductivity measurement results showed that the electrical conductivity of chitin modi�ed with trimellitic anhydride (1.2 × 10 −4 S cm −1) is higher than that of chitin modi�ed with phthalic anhydride (9.2 × 10 −5 S cm −1).

Journal of Turkish Studies

Organic Communications

In this research, five novel hydrazone derivatives (2a-e) were obtained for the first time, chara... more In this research, five novel hydrazone derivatives (2a-e) were obtained for the first time, characterized and investigated for their antioxidant properties, and acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities. The target molecules were easily synthesized by the condensation reaction of 2,4dinitrophenylhydrazine (2,4-DNPH) with aryl esters (1a-e) derived from salicylaldehyde as a starting material. These molecules were fully elucidated by some spectroscopic techniques and elemental analysis. Antioxidant activities of newly synthesized molecules were examined by CUPRAC reducing, ABTS and DPPH radical scavenging assays. The IC50 values of the screened molecules were determined in the range of 72.54-221.52 µM against AChE and in the range of 8.46-48.28 µM against BChE. Among the tested molecules, compound 2e indicated the highest activity against both AChE and BChE. Also, the inhibitory capacities of all tested molecules were compared to the standard molecules galanthamine. On the other hand, In CUPRAC reducing assay, the target molecules exhibited antioxidant activities in the range of 30.29 and 59.43 µM. Among these compounds, compound 2b (IC50=30.29 µM) showed the closest activity to the standard compounds butylated hydroxytoluene (BHT) (IC50=30.62 µM) and butylated hydroxyanisole (BHA) (IC50=34.24 µM).

Middle East Journal of Science

In this manuscript, five novel Schiff base derivatives containing a pyrazolone ring and a sulfona... more In this manuscript, five novel Schiff base derivatives containing a pyrazolone ring and a sulfonate moiety (6-10) except for 9 were designed, obtained for the first time and characterized by three spectroscopic techniques. The inhibition performances of these moleucles synthesized in two steps against cholinesterases, namely acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were evaluated. By DPPH and ABTS assays, antioxidant activities of these molecules were also examined. In AChE assay, compound 6 (95.87±1.59 % inhibition) inhibited this enzyme better than galanthamine (76.98±0.42 % inhibition). In BChE assay, compound 10 with 87.92±1.08% inhibition value in the series indicated the highest activity compared to galanthamine (76.30±0.28 % inhibition). In ABTS radical scavenging assay, compounds 7, 8 and 9 except for 6 and 10 indicated higher antioxidant activities compared to butylated hydroxytoluene (BHT). It is believed that these results may contribute to the design ...

Journal of Turkish Studies, 2018

doğada bulunan en saf sulardır", "Su tüm sıvı haldeki maddelerle karışır", "Su net bir dipol mome... more doğada bulunan en saf sulardır", "Su tüm sıvı haldeki maddelerle karışır", "Su net bir dipol momente sahiptir", "Bir insanın biyolojik ihtiyaçlarını karşılaması ve yaşamını sürdürebilmesi için, günde en az 1 litre su tüketmesi gerektiği kabul edilir" gibi maddelerde kavram yanılgıları taşıdıkları görülmüştür. Bu bulgulardan hareketle araştırmacı ve uygulayıcılar için bazı öneriler verilmiştir.

The Journal of Academic Social Science Studies, 2012

Sempozyumu'nda (Batman Üniversitesi) sözlü bildiri olarak sunulmuĢ ve özetler kitapçığında özet m... more Sempozyumu'nda (Batman Üniversitesi) sözlü bildiri olarak sunulmuĢ ve özetler kitapçığında özet metin olarak basılmıĢ çalıĢmadan üretilmiĢtir.

International Journal of Molecular Sciences, 2007

The constants of the extraction equilibrium and the distribution for dichloromethane as an organi... more The constants of the extraction equilibrium and the distribution for dichloromethane as an organic solvent having low dielectric constant of metal cations with chiral Schiff bases, benzaldehydene-(S)-2-amino-3-phenylpropanol (I), ohydroxybenzaldehydene-(S)-2-amino-3-phenyl-propanol (II), benzaldehydene-(S)-2amino-3-methylbutanol (III) with anionic dyes [4-(2-pyridylazo)-resorcinol mono sodium monohydrate (NaPar), sodium picrat (NaPic) and potassium picrat (KPic)] and some heavy metal chlorides were determined at 25 o C. All the ligands have given strongest complexation for NaPar. In contrast, similar behaviour for both alkali metal picrates is not apparent in the complexation of corresponding ligands.

Synthesis and Reactivity in Inorganic and Metal-Organic Chemistry, 2001

This study represents a new synthesis of two organotellurium compounds and their dyeing propertie... more This study represents a new synthesis of two organotellurium compounds and their dyeing properties. The structure of these tellurium derivatives are proposed based on elemental analyses, IR, UV-Vis, H and C NMR spectra and thermogravimetric analyses (TGA).

Microchimica Acta, 2004

Two diaza-crown ether compounds were synthesized and evaluated as Ag þ-selective carriers in poly... more Two diaza-crown ether compounds were synthesized and evaluated as Ag þ-selective carriers in polyvinylchloride (PVC) membrane electrodes of solid-state type. The all-solid-state PVC membrane electrode based on N,N-Dibenzyl-dibenzo-diaza-18-crown-6 exhibited a super-Nernstian response (75 AE 10 mV per decade) over the concentration range of 1Â10 À1 to 7Â10 À6 M of Ag þ ion and a detection limit of 3Â10 À6 M, at a wide range of pH (pH 4-7). The response time of the electrode was fast (less than $10s), and it can be used for three months without any significant deviation in potential. The proposed all-solid-state PVC membrane electrodes revealed high selectivity toward Ag þ ion with respect to alkali, alkaline earth, heavy and transition metal ions. A flow-through cell of all-solid-state PVC membrane Ag þ-selective electrode based on N,N-Dibenzyl-dibenzo-diaza-18-crown-6 has also been prepared and applied for flow-injection analysis of Ag þ ion in solution.

Applied Surface Science, 2005

The temperature dependent electronic characteristics of Pt Schottky barriers fabricated on lightl... more The temperature dependent electronic characteristics of Pt Schottky barriers fabricated on lightly and relatively highly doped n-type 4H-SiC (1 ' 10 16 and 1 ' 10 18 cm %3) are comparatively investigated. It is found that the abnormal temperature dependence of barrier height and ideality factor estimated from the thermionic emission (TE) model for both lightly and highly doped samples could be successfully explained in terms of Gaussian distribution of inhomogeneous barrier heights. However, the estimated mean barrier height according to Gaussian distribution for the highly doped sample is much lower than the actual mean value from the capacitance-voltage (C-V) measurements. Interestingly, the values of barrier height from the thermionic field emission (TFE) model are found to be close to those from the C-V measurements, indicating that the TFE model is more appropriate to explain the electrical transport for the highly doped sample.

Chemical Engineering and Processing: Process Intensification, 2007

In this paper Genetic Programming (GP) method was used to predict the removal of hexavalent chrom... more In this paper Genetic Programming (GP) method was used to predict the removal of hexavalent chromium as one of main pollutant of wastewater using nanotube carbon as the adsorbent. One set of experimental data was chosen for this aim. The considered parameters as input of the network were adsorbent dosage, initial solution pH, initial concentration of Cr(VI), contact time and temperature and the output parameter of the network was final concentration of Cr(VI). GP applied for two groups of data, namely, kinetic and equilibrium and two correlations presented for these groups. The determined correlations using the GP had excellent precision. The correlations were used to determine appropriate model for both kinetic and equilibrium of adsorption. The results showed that the kinetic and equilibrium of adsorption fitted on the pseudosecond-order and Langmuir isotherm models, respectively. Activation energy and enthalpy of adsorption were determined using the models.