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Articles 11221 - 11250 of 33250

Full-Text Articles in Chemistry

Gold-Assembled Silica-Coated Cobalt Nanoparticles As Efficient Magnetic Separation Units And Surface-Enhanced Raman Scattering Substrate, Lütfi̇ye Sezen Yildirim, Murat Kaya, Mürvet Volkan Jan 2019

Gold-Assembled Silica-Coated Cobalt Nanoparticles As Efficient Magnetic Separation Units And Surface-Enhanced Raman Scattering Substrate, Lütfi̇ye Sezen Yildirim, Murat Kaya, Mürvet Volkan

Turkish Journal of Chemistry

Magnetic and optical bifunctional nanoparticles that combine easy separation, preconcentration, and efficient SERS capabilities have been fabricated with high sensitivity and reproducibility through a low-cost method. These gold nanoparticles attached on magnetic silica-coated cobalt nanospheres (Co@SiO$_{2}$/AuNPs) display the advantage of strong resonance absorption due to gaps at nanoscale between neighboring metal nanoparticles bringing large field enhancements, known as "hot spots". The prepared particles can be controlled by using an external magnetic field, which makes them very promising candidates in biological applications and Raman spectroscopic analysis of dissolved organic species. The magnetic property of the prepared particles lowers the detection limits …

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Computational Investigation Of Influenza A Virus M2 Protein Inhibition Mechanism By Ion Channel Blockers, Mehmet Özbi̇l Jan 2019

Computational Investigation Of Influenza A Virus M2 Protein Inhibition Mechanism By Ion Channel Blockers, Mehmet Özbi̇l

Turkish Journal of Chemistry

The M2 protein of the influenza A virus, responsible for flu, is a homotetramer transmembrane protein, forming a transmembrane ion channel, where His 37s act as pH sensors and Trp 41s and Asp 44s act as channel gates. Opening of this channel leads to transfer of virus RNA into the human host. Thus, blocking this transfer is an important pharmaceutical strategy to stop infection. As a result of viral drug resistance, commercially available channel inhibitors, rimantadine (RIM) and amantadine (AMA), are not as effective as they used to be. Understanding binding sites and outcomes of binding will lead to new …

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New Diazo-Containing Phenolic Oximes: Structural Characterization, Computational Studies, And Solvent Extraction Of Cu(Ii), Ni(Ii), And Zn(Ii) Ions, Muharrem Karabörk, Hi̇lal Kirpik, Koray Sayin, Muhammet Köse Jan 2019

New Diazo-Containing Phenolic Oximes: Structural Characterization, Computational Studies, And Solvent Extraction Of Cu(Ii), Ni(Ii), And Zn(Ii) Ions, Muharrem Karabörk, Hi̇lal Kirpik, Koray Sayin, Muhammet Köse

Turkish Journal of Chemistry

In the current study, four new phenolic oxime ligands (HL1ox-HL4ox) containing diazo groups (-N$=$N-) were synthesized and used for liquid-liquid extraction of heavy metal ions [Cu(II), Ni(II), and Zn(II)]. The new compounds were characterized by analytical and spectroscopic methods. Solid-state structures of HL1ox-HL3ox were determined by single-crystal X-ray diffraction studies. Hirshfeld surface analysis of the compounds was performed to determine the contribution of different intermolecular contacts to the stability of the structures. The HL1ox-HL4ox ligands showed higher extraction performance for Cu(II) ion than Ni(II) and Zn(II) ions. The effect of pH on extraction capacity was investigated and the oxime compounds …

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Preparation Of $\Alpha $-Hydroxyphenylacetic Acid With Cyclodextrins As An Effective Phase-Transfer Catalyst And Its Reaction Mechanism, Bing Ren Tian, Rui Xia Zhang, Hui Min Chu, Qing Huang, Zhi Zhong Wang Jan 2019

Preparation Of $\Alpha $-Hydroxyphenylacetic Acid With Cyclodextrins As An Effective Phase-Transfer Catalyst And Its Reaction Mechanism, Bing Ren Tian, Rui Xia Zhang, Hui Min Chu, Qing Huang, Zhi Zhong Wang

Turkish Journal of Chemistry

An effective procedure for the synthesis of $\alpha $-hydroxyphenylacetic acid with cyclodextrin (CD) catalysts was developed. The phase-transfer catalyst types, catalyst loadings, reaction times, reaction temperatures, and substrate molar ratios were investigated to optimize the reaction conditions. In addition, the factors that affect the reaction were studied, and the relationship between benzaldehyde and $\beta $-cyclodextrin ($\beta $-CD) was analyzed through 2D-ROESY. The equilibrium constant when $\beta $-CD was used as the catalyst was calculated. The results indicated that $\beta $-CD is the optimal catalyst for the reported reaction (yield: 69.08%). Furthermore, the mechanism underlying the reported reaction was proposed.

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Crystal Structure And Hirshfeld Surface Analysis Of 1,2-Ethylene-Bis (Para-Methyl Pyridinium) Dichromate As A New Selective And Mild Agent In Oxidation Of Alcohols, Mostafa Gholizadeh, Mehrdad Pourayoubi, Mohammad Reza Houssiendokht, Hadi Amiri Rudbari, Masoumeh Farimaneh, Anahid Saneei, Giuseppe Bruno Jan 2019

Crystal Structure And Hirshfeld Surface Analysis Of 1,2-Ethylene-Bis (Para-Methyl Pyridinium) Dichromate As A New Selective And Mild Agent In Oxidation Of Alcohols, Mostafa Gholizadeh, Mehrdad Pourayoubi, Mohammad Reza Houssiendokht, Hadi Amiri Rudbari, Masoumeh Farimaneh, Anahid Saneei, Giuseppe Bruno

Turkish Journal of Chemistry

1,2-Ethylene-bis(para-methyl pyridinium) dichromate, (C$_{14}$H$_{18}$N$_{2})$[Cr$_{2}$O$_{7}$], is used as a new oxidizing agent in conversion of some alcohols to their corresponding carbonyl compounds in CH$_{3}$CN solvent and also under solvent-free conditions. In both procedures, high conversion percentages are observed. However, a much shorter reaction time is achieved in solvent-free conditions. For allylic alcohols, the C=C bond is not oxidized and the examined saturated alcohol in this work (i.e. cyclo-hexanol) remains intact, which illustrates the mild nature of reagent used. The structure of the reagent is investigated by single-crystal X-ray diffraction analysis. The C--H$\cdots$O and O$\cdots \pi$ interactions are the most important features …

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Characterization And Purification Of 1,2,4-Triazole-Containing Phthalocyanines Synthesized By Microwave Method And Structure Elucidation By Spectroscopic Techniques, Asi̇ye Nas, Ümi̇t Demi̇rbaş, Nurhan Gümrükçüoğlu, Hali̇t Kanteki̇n Jan 2019

Characterization And Purification Of 1,2,4-Triazole-Containing Phthalocyanines Synthesized By Microwave Method And Structure Elucidation By Spectroscopic Techniques, Asi̇ye Nas, Ümi̇t Demi̇rbaş, Nurhan Gümrükçüoğlu, Hali̇t Kanteki̇n

Turkish Journal of Chemistry

The complexes of peripherally tetra-substituted metal-free (8), lead(II) 9), and zinc(II) (10) phthalocyanine derivatives were synthesized for the first time in this work. The structures of these new complex compounds have been elucidated using many spectral methods such as electronic absorption, FT-IR, $^{1}$H NMR, $^{13}$C NMR, elemental analysis, and mass spectra. The thermogravimetric behavior of compounds 8-10 was determined by thermogravimetric analysis method in addition to these spectral methods.

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3d-Qsar/Hqsar-Based Analysis Of Bioconcentration And Molecular Modification Of Monophenyl Aromatic Compounds, Qing Li, Wenwen Gu, Yu Li Jan 2019

3d-Qsar/Hqsar-Based Analysis Of Bioconcentration And Molecular Modification Of Monophenyl Aromatic Compounds, Qing Li, Wenwen Gu, Yu Li

Turkish Journal of Chemistry

Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) of three-dimensional quantitative structure-activity relationship (3D-QSAR) models were conducted using 36 aromatic compound congeners as the training set and eight aromatic compound congeners as the test set. Logarithms of experimental bioconcentration data (logBCF) were used as dependent variables and the physicochemical properties of the aromatic compound congeners were used as independent variables. Furthermore, the molecular holographic quantitative structure--activity relationship (HQSAR) model constructed by the HQSAR module in Sybyl software was used to establish a method to find molecular activity substitution sites of bioconcentration potential by coupling the molecule …

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Investigation Of The Structural And Physicochemical Requirements Of Quinoline-Arylamidine Hybrids For The Growth Inhibition Of K562 And Raji Leukemia Cells, Vesna Rastija, Marijana Jukic, Teuta Opacak-Bernardi, Luka Krstulovic, Ivana Stolic, Ljubica Glavac-Obrovac, Miroslav Bajic Jan 2019

Investigation Of The Structural And Physicochemical Requirements Of Quinoline-Arylamidine Hybrids For The Growth Inhibition Of K562 And Raji Leukemia Cells, Vesna Rastija, Marijana Jukic, Teuta Opacak-Bernardi, Luka Krstulovic, Ivana Stolic, Ljubica Glavac-Obrovac, Miroslav Bajic

Turkish Journal of Chemistry

Quantitative structure-activity relationship (QSAR) analysis of 28 quinoline-arylamidine (CQArA) hybrids against two leukemia cells, K562 and Raji, was performed. Multiple linear regression (MLR) models were obtained by genetic algorithm. The best models involved the following descriptors: radial distribution function (RDF) descriptors, GETAWAY (GEometry, Topology, and Atom-Weights AssemblY) descriptor, bond information content index, and dipole moment. The best MLR models for K562 and Raji cells demonstrated satisfactory stability in internal and external validation. Since the QSAR model for Raji cells has better predictive ability, two new highly potent CQArA analogues were proposed based on it. The QSAR models revealed important physicochemical …

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Plasma Polymerized Linalool (Pplin): An Antimicrobial And Biocompatible Coating, Kenan Çakmak, Özkan Bayram, Kübra Solak, Güzi̇n Kaban, Önder Şi̇mşek, Ahmet Mavi̇ Jan 2019

Plasma Polymerized Linalool (Pplin): An Antimicrobial And Biocompatible Coating, Kenan Çakmak, Özkan Bayram, Kübra Solak, Güzi̇n Kaban, Önder Şi̇mşek, Ahmet Mavi̇

Turkish Journal of Chemistry

Bacterial infections in medical devices and drug resistance of bacteria can cause chaos in the world due to loss of lives in addition to the cost of device revisions, quarantine, disinfection of infected areas, and patient treatment. Antibacterial coatings of essential oils on medical devices can prevent bacterial attachment and reduce costs. Linalool is an antibacterial constituent of essential oils. Herein, we examine for the first time the fabrication and characterization of radio frequency (RF) plasma polymerized hydrophilic thin films from linalool (ppLin) by varying deposition parameters (RF power and deposition time) and the behavior of ppLin with two bacteria …

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New Flavonoid Glycosides Conjugates: Synthesis, Characterization, And Evaluation Of Their Cytotoxic Activities, Sawssen Souiei, Fatima Bousejra-El Garah, Mohamed Amine Belkacem, Mansour Znati, Jalloul Bouajila, Hichem Ben Jannet Jan 2019

New Flavonoid Glycosides Conjugates: Synthesis, Characterization, And Evaluation Of Their Cytotoxic Activities, Sawssen Souiei, Fatima Bousejra-El Garah, Mohamed Amine Belkacem, Mansour Znati, Jalloul Bouajila, Hichem Ben Jannet

Turkish Journal of Chemistry

A series of novel halogenated 3-hydroxyflavones (3HFs) were prepared by reacting halogenated hydroxyacetophenones with the appropriate aromatic aldehyde. Glycosylation of 3HFs with acetobromoglucose and deprotection of the acetyl protective groups afforded the desired 3-$O$-flavonoids glycosides in satisfactory yields. All the prepared compounds were tested for their cytotoxic activity against HCT-116, MCF-7, and OVCAR-3 human cancer cell lines. The 3HFs exhibited higher cytotoxic activities compared with the glycosylated flavonoids. Overall, the structure-activity relationship study showed that the introduction of glycoside moiety at the C-3 OH position does not improve the bioactivity.

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Biodegradability Study Of Polypropylene Fibers Blended With Disposable Recycled Poly(Lactic Acid) Plastic Flakes, Mohammad Ali Tavanaie, Abolfazl Mahmudi Gevari Jan 2019

Biodegradability Study Of Polypropylene Fibers Blended With Disposable Recycled Poly(Lactic Acid) Plastic Flakes, Mohammad Ali Tavanaie, Abolfazl Mahmudi Gevari

Turkish Journal of Chemistry

Polymer blending as an efficient method for blending at least two~polymers is usually used to create new materials with desirable physical properties. This article focuses on the biodegradability evaluation of polypropylene (PP) fibers modified with disposable recycled poly(lactic acid) (r-PLA) plastic flakes. Biodegradable modified PP fibers containing 30% r-PLA were prepared by melt spinning process and evaluated with different methods of biodegradation assays. The soil burial test method, CO$_{2}$ evolution analysis, weight loss, mechanical properties, and average molecular weight measurements and analysis of surface morphological changes were performed for biodegradability evaluation of the modified PP fibers. Surface morphology of the …

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Why Protein Conformers In Molecular Dynamics Simulations Differ From Their Crystal Structures: A Thermodynamic Insight, Fi̇li̇ppo Pullara, Mao Wenzhi, Mert Gür Jan 2019

Why Protein Conformers In Molecular Dynamics Simulations Differ From Their Crystal Structures: A Thermodynamic Insight, Fi̇li̇ppo Pullara, Mao Wenzhi, Mert Gür

Turkish Journal of Chemistry

Conformers generally deviate structurally from their starting X-ray crystal structures early in molecular dynamics (MD) simulations. Studies have recognized such structural differences and attempted to provide an explanation for and justify the necessity of MD equilibrations. However, a detailed explanation based on fundamental physics and validation on a large ensemble of protein structures is still missing. Here we provide the first thermodynamic insights into the radically different thermodynamic conditions of crystallization solutions and conventional MD simulations. Crystallization solution conditions can lead to nonphysiologically high ion concentrations, low temperatures, and crystal packing with strong specific protein--protein interactions, not present under physiological …

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Investigation Of The Ideal Composition Of Metal Hexacyanocobaltates With High Water Oxidation Catalytic Activity, Ferdi̇ Karadaş Jan 2019

Investigation Of The Ideal Composition Of Metal Hexacyanocobaltates With High Water Oxidation Catalytic Activity, Ferdi̇ Karadaş

Turkish Journal of Chemistry

The electrocatalytic activities of Prussian blue analogues (PBAs) have recently received much attention due to their robustness and efficiency. Considering that PBAs with hexacyanocobaltate building block stand forward among other PBAs, a systematic study on a family of metal hexacyanocobaltates is presented in this study. Metal hexacyanocobaltates (M $=$ Co, Mn, Ni, and Fe) were prepared, characterized, and electrochemical studies were performed. A series of mixed-metal cobalt-iron hexacyanocobaltates has also been studied to determine the ideal composition of a metal hexacyanocobaltate for electrocatalytic water oxidation process. The overall study clearly indicates that cobalt hexacyanocobaltate exhibits the highest electrocatalytic activity among …

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Spectrophotometric Methods For The Determination Of Fluoride Ion Using Indole-3-Acetic Acid Interaction With Iron(Iii), Emi̇ne İlknur Öztürk, Adnan Kenar, Mehmet Levent Aksu, Mustafa Taşteki̇n Jan 2019

Spectrophotometric Methods For The Determination Of Fluoride Ion Using Indole-3-Acetic Acid Interaction With Iron(Iii), Emi̇ne İlknur Öztürk, Adnan Kenar, Mehmet Levent Aksu, Mustafa Taşteki̇n

Turkish Journal of Chemistry

This study is related to the determination of fluoride ion by the conversion of pink-colored Fe(III) and indole-3-acetic acid (IAA) into a colorless hexafluoride ferrite complex with the addition of fluoride. The optimum conditions of the complex formation were found to be pH 1.7 and a temperature of 60 $^{\circ}$C C. The maximum absorption wavelength of the complex and the detection limit of the method were 525 nm and 0.26 mg/L, respectively. The interfering effects of the different cations (Ag$^{+}$, Al$^{3+}$, Ba$^{2+}$, Ca$^{2+}$, Cd$^{2+}$, Co$^{2+}$, Cu$^{2+}$, K$^{+}$, Mg$^{2+}$, Na$^{+}$, Ni$^{2+}$, Pb$^{2+})$ and anions (SO$_{4}^{2-}$, SO$_{3}^{2-}$, NO$_{2}^{-}$, I$^{-}$, Br$^{-}$, Cl$^{-}$, SCN$^{-}$, …

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Acid-Activated Clay As Heterogeneous And Reusable Catalyst For The Synthesis Of Bioactive Cyclic Ketal Derivatives, Wided Hagui, Rym Essid, Sondes Amri, Nadia Fares, Mohamed Khabbouchi, Olfa Tabbene, Ferid Limam, Ezzedine Srasra, Neji Besbes Jan 2019

Acid-Activated Clay As Heterogeneous And Reusable Catalyst For The Synthesis Of Bioactive Cyclic Ketal Derivatives, Wided Hagui, Rym Essid, Sondes Amri, Nadia Fares, Mohamed Khabbouchi, Olfa Tabbene, Ferid Limam, Ezzedine Srasra, Neji Besbes

Turkish Journal of Chemistry

A new heterogeneous acid catalyst based on a natural resource, Tunisian clay (Clay-H0.5), has been prepared and characterized by FT-IR, FE-SEM, and powder X-ray diffraction (XRD), as well as chemical composition, cation exchange capacity, specific surface area, and pore volume. Acid treatment for 0.5 h enlarged the surface area from 78.24 to 186.10 m$^{2}$/g and pore volume (PV) from 0.186 to 0.281 cm$^{3}$/g. The catalytic activity of this material was investigated in ketalization reaction under mild solvent-free conditions. This achieved up to 92% isolated yield for only 10 wt.% of the catalyst. This environmentally friendly method has advantages such as …

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Boric Acid As An Efficient And Green Catalyst For The Synthesis Of 2-Amino-4,6-Diarylnicotinonitrile Under Microwave Irradiation In Solvent-Free Conditions, Zahra Hosseinzadeh, Ali Ramazani, Nima Razzaghi-Asl, Katarzyna Slepokura, Tadeusz Lis Jan 2019

Boric Acid As An Efficient And Green Catalyst For The Synthesis Of 2-Amino-4,6-Diarylnicotinonitrile Under Microwave Irradiation In Solvent-Free Conditions, Zahra Hosseinzadeh, Ali Ramazani, Nima Razzaghi-Asl, Katarzyna Slepokura, Tadeusz Lis

Turkish Journal of Chemistry

Microwave irradiation has been used to improve the one-pot synthesis of substituted 2-amino-4,6-diarylnicoti- nonitrile in the presence of boric acid as an efficient and green catalyst under solvent-free conditions within 48--60 s. All the analogs that have not been reported previously were characterized by their melting points, IR, $^{1}$H NMR, and $^{13}$C NMR spectra. One of the structures was verified by the analysis of a single crystal. The reported synthetic procedure provided remarkable advantages such as short reaction times, excellent yield, facile workup, and the use of a green catalyst.

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Organotemplate-Free Cs-Abw Nanozeolite As Highly Reactive And Recyclable Catalyst For Henry Reaction Between Benzaldehyde And Nitroethane, Tamara Mahmoud Ali Ghrear, Ka Lun Wong, Soon Huat Tan, Tau Chuan Ling, Hussein Awala, Engpoh Ng Jan 2019

Organotemplate-Free Cs-Abw Nanozeolite As Highly Reactive And Recyclable Catalyst For Henry Reaction Between Benzaldehyde And Nitroethane, Tamara Mahmoud Ali Ghrear, Ka Lun Wong, Soon Huat Tan, Tau Chuan Ling, Hussein Awala, Engpoh Ng

Turkish Journal of Chemistry

Zeolite Cs-ABW nanocatalyst has been hydrothermally synthesized without using any harmful organic template. The zeolite nanocrystal with very high solid yield (81.88%) can be obtained within 60 min and at 180 $^{\circ}$C (∼ 20 atm), conditions that are much faster and gentler than the existing synthesis methods. The orthorhombic Cs-ABW nanocrystals (mean size of 32 nm) have high aluminum content (Si/Al ratio $=$ 1.14) and possess high basicity. The nanocrystals also exhibit better catalytic activity than conventional homogeneous catalysts in the Henry (nitroaldol) reaction of benzaldehyde with nitroethane under microwave heating conditions. The nanocatalyst does not suffer from coking and …

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Removal Of Cr(Vi) From Wastewater Through Glycine Assisted Synthesis Of Tio$_{2}$, Bi̇lsen Kurtteki̇n, Demet Özer, Nurşen Altuntaş Öztaş Jan 2019

Removal Of Cr(Vi) From Wastewater Through Glycine Assisted Synthesis Of Tio$_{2}$, Bi̇lsen Kurtteki̇n, Demet Özer, Nurşen Altuntaş Öztaş

Turkish Journal of Chemistry

In this study, titanium dioxide was synthesized via solution combustion method. Titanium(IV) oxysulfate was used as a titanium source. The fuel type, reaction time, and reaction temperature were tested for optimization. The glycine was set as a suitable fuel. Structural properties of the final product were characterized by p-XRD. Scanning electron microscopy (SEM) and BET techniques were used to examine the morphology. The synthesized products were compared to the commercial TiO$_{2}$ and it was found that the titanium dioxide with the high surface area (63.628 m$^{2}$/g) has been successfully synthesized by solution combustion method with time and energy saving. In …

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The Effect Of Washing On Stabilized And Unstabilized Low-Density Polyethylene Films Naturally Weathered In A Sub-Saharan Region (Ghardaia, Algeria, Souad Behissa, Salem Fouad Chabira, Nourelhouda Benmiloud, Mohamed Sebaa Jan 2019

The Effect Of Washing On Stabilized And Unstabilized Low-Density Polyethylene Films Naturally Weathered In A Sub-Saharan Region (Ghardaia, Algeria, Souad Behissa, Salem Fouad Chabira, Nourelhouda Benmiloud, Mohamed Sebaa

Turkish Journal of Chemistry

The effect of washing stabilized and unstabilized blown extruded films of low-density polyethylene (LDPE) used for greenhouse coverings naturally weathered in a sub-Saharan facility at Ghardaia (Algeria) for 19 and 6 months, respectively, was studied. A comparison between unwashed and daily washed samples was done. The changes in the films' properties were followed at regular intervals using various characterization methods (physicochemical and mechanical). Although in both cases the chemical species formed due to the weathering were qualitatively the same, they essentially differed in their concentrations, namely they were higher for the washed samples than for the unwashed ones. Inversely, the …

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An Exploration Of New Avenues Regarding Deep Tissue Penetration And Higher Singlet Oxygen Efficiencies: Novel Near-Ir Photosensitizers For Photodynamic Therapy, Ni̇sa Yeşi̇lgül, Bi̇lal Kiliç Jan 2019

An Exploration Of New Avenues Regarding Deep Tissue Penetration And Higher Singlet Oxygen Efficiencies: Novel Near-Ir Photosensitizers For Photodynamic Therapy, Ni̇sa Yeşi̇lgül, Bi̇lal Kiliç

Turkish Journal of Chemistry

A series of novel BODIPY-bearing electron-withdrawing groups at the meso position are reported here. According to the optical measurements, it may be clearly seen that the introduction of electron-donating groups into 3,5-positions and the presence of electron-withdrawing groups at the meso position of the BODIPY core resulted in spectacular bathochromic shifts (up to ∼ 304 nm), and the projected photosensitizers had absorption bands in the therapeutic window of the electromagnetic spectrum (600-900 nm). The absorption maxima of compounds 4,5,6, and 7 were at 886 nm, 890 nm, 760 nm, and 761 nm, respectively. The singlet oxygen generation experiments revealed that …

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Intermolecular Complexes Of Halocyclopropenone Derivatives With The Hypohalous Acids Hof, Hocl, Hobr, And Hoi, Dariush Mirzaei, Abedien Zabardasti, Yaghoub Mansourpanah Jan 2019

Intermolecular Complexes Of Halocyclopropenone Derivatives With The Hypohalous Acids Hof, Hocl, Hobr, And Hoi, Dariush Mirzaei, Abedien Zabardasti, Yaghoub Mansourpanah

Turkish Journal of Chemistry

The intermolecular interactions between halocyclopropenone derivatives (HC$_{3}$OX; X $=$ I, Br, Cl, and F) and hypohalous acids (HOY; Y $=$ I, Br, Cl, and F) were studied via the MP2 method utilizing the aug-cc-pVTZ and aug-cc-pVTZ(-PP) basis sets. The three types of complexes were hydrogen bonds, halogen bonds, and complexes containing both hydrogen and halogen bonds. The results obtained indicated that interactions in the Type 1 complexes were stronger than those in Types 2 and 3. The H-O bonds revealed red shifts with complex formation in Types 1 and 2. The O-Y bonds displayed red shifts in the Type 3 …

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Preparation Of Epoxidized Sunflower Oil Metal Soap Derivatives And Their Use As Heat Stabilizers For Polyvinyl Chloride, Ouassila Chelil, Naima Belhaneche-Bensemra, Daniel Lopez Garcia, Marta Fernandez-Garcia, Mohamed Tahar Benaniba Jan 2019

Preparation Of Epoxidized Sunflower Oil Metal Soap Derivatives And Their Use As Heat Stabilizers For Polyvinyl Chloride, Ouassila Chelil, Naima Belhaneche-Bensemra, Daniel Lopez Garcia, Marta Fernandez-Garcia, Mohamed Tahar Benaniba

Turkish Journal of Chemistry

The aim of this work was to prepare metal soaps of epoxidized sunflower oil (ESO) and use them as thermal stabilizers for polyvinyl chloride (PVC). For that purpose, commercial sunflower oil was first epoxidized and then used to prepare (Ba, Zn, Pb, and Cd) metal soap derivatives, which were characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The prepared metal soaps derivatives of ESO were used as thermal stabilizers for plasticized PVC. Discoloration, residual thermal stability at 200 $^{\circ}$C , and rheological properties of PVC samples were tested. The structural modifications were investigated …

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Effect Of Crosslinking Patterns On The Properties Of Conjugated Microporous Polymers, Hakan Bi̇ldi̇ri̇r Jan 2019

Effect Of Crosslinking Patterns On The Properties Of Conjugated Microporous Polymers, Hakan Bi̇ldi̇ri̇r

Turkish Journal of Chemistry

Syntheses and detailed spectroscopic characterizations of two similar conjugated microporous polymers formed by A4 $+$ B2 and A2 $+$ B3 type functional monomers via Sonogashira--Hagihara polycondensation are presented in this report. The two porous polymeric networks possess mono-, di-, and tri- (1-, 1,4-, and 1,3,5-, respectively) substituted benzene rings and fused thiophenic moieties (dithienothiophenes). Because of the different conjugation patterns, their solid state nuclear magnetic resonance, infrared, and ultraviolet/visible light absorption analyses indicated significant differences. Besides the discussions on the porous properties of the obtained polymeric networks, the presented spectroscopic investigations can be useful for identifying the structure-property relationship of …

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Chiral 1,4-Aminoalkylphenols For Enantioselective Diethylzinc Addition To Aldehydes, Ömer Di̇lek, Mustafa Ali̇ Tezeren, Tahi̇r Ti̇lki̇, Erkan Ertürk Jan 2019

Chiral 1,4-Aminoalkylphenols For Enantioselective Diethylzinc Addition To Aldehydes, Ömer Di̇lek, Mustafa Ali̇ Tezeren, Tahi̇r Ti̇lki̇, Erkan Ertürk

Turkish Journal of Chemistry

Starting from a chiral secondary alcohol, novel enantiopure 1,4-aminoalkylphenols (AAPs) were prepared by exploiting conventional organic transformations such as the Mitsunobu reaction, Eschweiler--Clarke N-methylation, and demethylation of anisoles. The catalytic activity of the 1,4-AAPs was investigated in enantioselective Et$_{2}$Zn addition to benzaldehyde. They were found to accelerate the Et$_{2}$Zn addition to benzaldehyde. High yields and enantioselectivities (e.g., 95% yield and 82% ee) were achieved.

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Modification Of Biomass-Derived Activated Carbon With Magnetic $\Alpha $-Fe$_{2}$O$_{3}$ Nanoparticles For Co$_{2}$ And Ch$_{4}$ Adsorption, Çi̇sem Kirbiyik Jan 2019

Modification Of Biomass-Derived Activated Carbon With Magnetic $\Alpha $-Fe$_{2}$O$_{3}$ Nanoparticles For Co$_{2}$ And Ch$_{4}$ Adsorption, Çi̇sem Kirbiyik

Turkish Journal of Chemistry

Magnetic and nonmagnetic activated carbons (ACs) were successfully prepared by using AC obtained from spent coffee grounds (SCGs) for use in CO$_{2}$ and CH$_{4}$ capture. SCGs were activated by chemical activation to produce ACs and a magnetic $\alpha $-Fe$_{2}$O$_{3}$/AC composite was prepared by coprecipitation method from the ACs produced. Magnetic and nonmagnetic samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive X-ray spectrometry (EDX) techniques. The textural properties of samples were determined by nitrogen adsorption-desorption using the Brunauer--Emmett--Teller (BET) and Barrett--Joyner--Halenda (BJH) methods. The results showed that the porosity of …

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Synthesis And Antimicrobial Activity Of 1-(Benzo[B]Thiophen-4-Yl)-4-(2-(Oxo, Hydroxyl, And Fluoro)-2-Phenylethyl)Piperazine And 1-(Benzo[D]Isothiazole-3-Yl)-4-(2-(Oxo, Hydroxy, And Fluoro)-2-Phenylethyl)Piperazine Derivatives, Vaibhav Mishra, Tejpal Singh Chundawat Jan 2019

Synthesis And Antimicrobial Activity Of 1-(Benzo[B]Thiophen-4-Yl)-4-(2-(Oxo, Hydroxyl, And Fluoro)-2-Phenylethyl)Piperazine And 1-(Benzo[D]Isothiazole-3-Yl)-4-(2-(Oxo, Hydroxy, And Fluoro)-2-Phenylethyl)Piperazine Derivatives, Vaibhav Mishra, Tejpal Singh Chundawat

Turkish Journal of Chemistry

Twenty-two compounds in a series of 1-(benzo[$b$]thiophen-4-yl)-4-(2-(oxo, hydroxy, and fluoro)-2-phenylethyl) piperazine and 1-(benzo[$d$]isothiazole-3-yl)-4-(2-(oxo, hydroxy, and fluoro)-2-phenylethyl)-piperazine derivatives were synthesized through nucleophilic substitution reaction of phenacyl bromides with hetero arylpiperazine, reduction, and then fluorination. Compound K2 showed potent activity against gram-negative bacterial stain P. aeruginosa with minimum inhibitory concentration (MIC) value of 12.5 μg/mL. This compound showed better inhibitory activity than the standard drug chloramphenicol. K4 against S. aureus, H2 against P. aeruginosa, and F4 against E. coli showed good inhibitory activity with MIC values of 62.5 μg/mL. Compounds K1, K2, K4, K8, F1, and F3 showed good inhibitory activity against …

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A Case Study Of Antiaromaticity: Carbomethoxy Cyclopropenyl Anion, Zi̇kri̇ Altun, Erdi̇ Ata Bleda, Carl Trindle Jan 2019

A Case Study Of Antiaromaticity: Carbomethoxy Cyclopropenyl Anion, Zi̇kri̇ Altun, Erdi̇ Ata Bleda, Carl Trindle

Turkish Journal of Chemistry

The simplest ideas of antiaromaticity refer to regular monocyclic systems and the eigenfunctions of the H\"{u}ckel Hamiltonian for 4n $\pi $ electrons in such systems. The antiaromaticity is expressed in the energy penalty for such idealized systems relative to the H\"{u}ckel energy for 2n noninteracting $\pi $ pairs. Observed systems seldom achieve the regular planar geometry assumed in this picture, owing to their ability to ease the antiaromaticity penalty by departures from the regular geometry and also by export of the 4n $\pi $ electrons' charge to substituents. In this report we estimate numerical values for the stabilization derived from …

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Investigation Of Sulfuric Acid-Treated Activated Carbon Properties, Neda Asasian Kolur, Seyedmehdi Sharifian, Tahereh Kaghazchi Jan 2019

Investigation Of Sulfuric Acid-Treated Activated Carbon Properties, Neda Asasian Kolur, Seyedmehdi Sharifian, Tahereh Kaghazchi

Turkish Journal of Chemistry

A granulated type of commercial activated carbon (GAC) with surface area of 828 m$^{2}$/g was treated with a strong solution of sulfuric acid (98% wt.) at a temperature of 30 $^{\circ}$C . The physicochemical and porous properties and the surface chemistry of the sorbents were investigated and compared in detail. It was established that the lower temperatures of impregnation and the higher concentration of H$_{2}$SO$_{4}$ solution resulted in the introduction of higher percentages of sulfur-containing groups and smaller porosity loss. The results of EDS, FTIR, and XPS tests confirmed the introduction of sulfone groups and acidic oxygenated ones, which increased …

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Effect Of Fe Substitution On The Partial Oxidation Of Methane To Syngas Over La$_{0.7}$Sr$_{0.3}$Co$_{1-Y}$Fe$_{Y}$O$_{3-\Delta}$ Perovskites, Adilah Aliyatulmuna, Perry Burhan, Bambang Prijamboedi, Hamzah Fansuri, Irmina Kris Murwani Jan 2019

Effect Of Fe Substitution On The Partial Oxidation Of Methane To Syngas Over La$_{0.7}$Sr$_{0.3}$Co$_{1-Y}$Fe$_{Y}$O$_{3-\Delta}$ Perovskites, Adilah Aliyatulmuna, Perry Burhan, Bambang Prijamboedi, Hamzah Fansuri, Irmina Kris Murwani

Turkish Journal of Chemistry

In this research, a series of La$_{0.7}$Sr$_{0.3}$Co$_{1-y}$Fe$_{y}$O$_{3-\delta }$ ($y =$ 0.0--0.4) was successfully synthesized by a solid-state reaction method and syngas production studies were performed using gas chromatography. Thermogravimetric analysis characterized the concentration of Fe$^{3+}$, which gave a low H$_{2}$/CO ratio over La$_{0.7}$Sr$_{0.3}$Co$_{1-y}$Fe$_{y}$O$_{3-\delta }$ without the presence of molecular oxygen. All samples possessed a purely rhombohedral structure. The incorporation of more Fe increased the lattice parameter and changed XRD peaks of the La$_{1-x}$Sr$_{x}$Co$_{0.8}$Fe$_{0.2}$O$_{3}$ from sharp and single to double. Among the catalyst powders tested for syngas production activity, La$_{0.7}$Sr$_{0.3}$Co$_{0.6}$Fe$_{0.4}$O$_{3-\delta }$ ($y =$ 0.4) had the low molar ratio of H$_{2}$/CO …

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Improvement Of The Mechanical And Thermal Properties Of Polyester Nonwoven Fabrics By Ptfe Coating, Fatemeh Ashrafi, Mohammad Reza Babaei Lavasani Jan 2019

Improvement Of The Mechanical And Thermal Properties Of Polyester Nonwoven Fabrics By Ptfe Coating, Fatemeh Ashrafi, Mohammad Reza Babaei Lavasani

Turkish Journal of Chemistry

Polyester (polyethylene terephthalate) is one of the most widely used polymers in textiles. Despite all the advantages of this polymer, its low thermal resistance limits its use in filters and protective textiles. On the other hand, polyester nonwovens are used in many products as wipes, filters, and padding. The surface properties of polyester nonwovens are often not perfect for a specific application and need to be modified. Different ways, including coating, have been developed to modify their surface properties. Therefore, in the present study attempts were made to investigate the improvement of the thermal resistance of a polyester nonwoven by …

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