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Articles 31 - 60 of 87
Full-Text Articles in Physical Sciences and Mathematics
Umpolung Strategy: Advances In Catalytic C-C Bond Formations, Serkan Eymur, Mehmet Göllü, Ci̇hangi̇r Tanyeli̇
Umpolung Strategy: Advances In Catalytic C-C Bond Formations, Serkan Eymur, Mehmet Göllü, Ci̇hangi̇r Tanyeli̇
Turkish Journal of Chemistry
This mini-review examines the recent advances in umpolung strategy, devised originally by Corey and Seebach. Although numerous stoichiometric variants have been published to date, this article covers just the catalytic C-C bond forming reactions due to their major benefits such as atom economy, less pollution, and workable simplicity. In the context of umpolung, the studies are evaluated under 3 main titles: enzyme, N-heterocyclic carbene, and cyanide ion catalyzed reactions. In particular, enzyme and NHC catalyzed reactions mainly involve asymmetric applications.
Droplet Condensation On Polymer Surfaces: A Review, İkri̇me Orkan Uçar, Hüsnü Yildirim Erbi̇l
Droplet Condensation On Polymer Surfaces: A Review, İkri̇me Orkan Uçar, Hüsnü Yildirim Erbi̇l
Turkish Journal of Chemistry
Dropwise condensation on substrates is an important topic of interest because it plays a crucial role in many scientific applications such as heat transfer, water harvesting from the humid atmosphere, and polymer templating. We focused on droplet condensation on polymer surfaces and briefly summarized the drop condensation studies reported in the last 2 decades and their potential applications. The main topics discussed in this review are water harvesting from dew using radiative cooling; using surfaces synthesized by bio-inspiration; experimental, theoretical, and simulation studies on the growth of breath figures; drop condensation on superhydrophobic surfaces and on self-assembled monolayers; and hexagonal …
Determination Of Zineb In Tap Water And Tomato Samples By Adsorptive Catalytic Stripping Voltammetry, Özlem Karakoç, Nuri̇ Naki̇boğlu
Determination Of Zineb In Tap Water And Tomato Samples By Adsorptive Catalytic Stripping Voltammetry, Özlem Karakoç, Nuri̇ Naki̇boğlu
Turkish Journal of Chemistry
This paper describes a sensitive and accurate adsorptive catalytic stripping voltammetric method for the determination of zineb (zinc ethylene-bis- dithiocarbamate) in tap water and tomato samples. The method is based on the reduction of adsorbed zineb at a hanging mercury drop electrode following its catalytic oxidation using peroxydisulfate as an oxidizing reagent. Chemical and instrumental parameters of the process were optimized. The catalytic mechanism of the reduction of zineb is discussed as well. The limits of detection (3 s) and quantification (10 s) and linear range of the method for accumulation time of 60 s were calculated as 8.1 nM, …
Ultrasound-Assisted Emulsification--Solidified Floating Organic Drop Microextraction Combined With Flow Injection--Flame Atomic Absorption Spectrometry For The Determination Of Palladium In Water Samples, Shayessteh Dadfarnia, Ali Mohammad Haji Shabani, Mooud Amirkavei
Ultrasound-Assisted Emulsification--Solidified Floating Organic Drop Microextraction Combined With Flow Injection--Flame Atomic Absorption Spectrometry For The Determination Of Palladium In Water Samples, Shayessteh Dadfarnia, Ali Mohammad Haji Shabani, Mooud Amirkavei
Turkish Journal of Chemistry
The ultrasound-assisted emulsification--solidified floating organic drop microextraction (USAE--SFODME) methodology was combined with flow injection--lame atomic absorption spectrometry (FI--FAAS) for the separation/pre\-concentration and determination of palladium at ultratrace level. In this method, the palladium ion in the aqueous solution was complexed with acetylacetone (6 \times 10^{-3} mol L^{-1}) in the pH range of 1--7 and was extracted into 40 \mu L of 1-undecanol, which was sonically dispersed in the aqueous phase. The vial was then centrifuged and cooled in an ice bath for 5 min. The solidified extract was melted and diluted to 100 \mu L with a solution of hydrochloric …
Poly(4-Vinylpyridine)-Supported Dual Acidic Ionic Liquid: An Environmentally Friendly Heterogeneous Catalyst For The One-Pot Synthesis Of 4,4'-(Arylmethylene)Bis(3-Methyl-1-Phenyl-1h-Pyrazol-5-Ols), Kaveh Parvanak Boroujeni, Pegah Shojaei
Poly(4-Vinylpyridine)-Supported Dual Acidic Ionic Liquid: An Environmentally Friendly Heterogeneous Catalyst For The One-Pot Synthesis Of 4,4'-(Arylmethylene)Bis(3-Methyl-1-Phenyl-1h-Pyrazol-5-Ols), Kaveh Parvanak Boroujeni, Pegah Shojaei
Turkish Journal of Chemistry
A poly(4-vinylpyridine)-supported Brønsted ionic liquid was easily prepared from its starting materials and used as a novel, highly efficient, and reusable heterogeneous catalytic system for the synthesis of 4,4'-(arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ols) from the condensation reaction between aromatic aldehydes and 2 equivalents of 3-methyl-l-phenyl-5-pyrazolone.
Synthesis Of 3,4-Diaryl-1-Phenyl-4,5-Dihydro-1h-Pyrazole-5-Carbonitriles Via 1,3-Dipolar Cycloaddition Reactions, Jayaroopa Prabhashankar, Vasanth Kumar Govindappa, Ajay Kumar Kariyappa
Synthesis Of 3,4-Diaryl-1-Phenyl-4,5-Dihydro-1h-Pyrazole-5-Carbonitriles Via 1,3-Dipolar Cycloaddition Reactions, Jayaroopa Prabhashankar, Vasanth Kumar Govindappa, Ajay Kumar Kariyappa
Turkish Journal of Chemistry
Nitrile imines generated by the oxidative dehydrogenation of aromatic aldehyde phenylhydrazones with chloramine-T as a catalytic dehydrogenating agent were trapped in situ by 4-methoxy cinnamonitrile to afford 3,4-diaryl-1-phenyl-4,5-dihydro-1H-pyrazole-5-carbonitrile in moderate to good yields. The structures of the cycloadducts were confirmed by spectral studies and elemental analysis.
Biodegradability Of Degradable Mulching Film In A Laboratory-Controlled Composting Test, Xuemei Zhang, Yaxi Huang, Deqiang Li, Zicheng Wen, Baoxun Sui, Zhiyong Liu
Biodegradability Of Degradable Mulching Film In A Laboratory-Controlled Composting Test, Xuemei Zhang, Yaxi Huang, Deqiang Li, Zicheng Wen, Baoxun Sui, Zhiyong Liu
Turkish Journal of Chemistry
A series of degradable films was prepared, and 2 formulas of polyethylene (PE) films with the highest degradable performance were experimentally determined. These films contained 3.43% and 0.44% stearate, and were denoted as PE-3 and PE-4, respectively. Their biodegradability was studied in a laboratory-controlled composting test using ordinary PE film (OPEF) as a control. Contrast composting experiments indicated that the biodegradability of untreated samples was very low, and that the biodegradation rates of PE films after natural aging were significantly higher. FT-IR analysis showed that OPEF changed little after the composting experiment, and that PE-3 and PE-4 showed a carbonyl …
Synthesis Of Tetrakis(Carboxyphenyl)Porphyrin Coated Paramagnetic Iron Oxide Nanoparticles Via Amino Acid For Photodegradation Of Methylene Blue, Rahmatollah Rahimi, Azadeh Tadjarodi, Mina Imani, Mahboubeh Rabbani, Samaneh Safalou Moghaddam, Hamed Kerdari
Synthesis Of Tetrakis(Carboxyphenyl)Porphyrin Coated Paramagnetic Iron Oxide Nanoparticles Via Amino Acid For Photodegradation Of Methylene Blue, Rahmatollah Rahimi, Azadeh Tadjarodi, Mina Imani, Mahboubeh Rabbani, Samaneh Safalou Moghaddam, Hamed Kerdari
Turkish Journal of Chemistry
In this paper, synthesis of tetrakis(carboxyphenyl)porphyrin (TCPP) coated cadmium ferrite (CdFe_2O_4) nanoparticles by using L-lysine as an anchor is reported for the first time. The ferrimagnetic CdFe_2O_4 nanoparticles were prepared via the facile self-assembly method of reflux followed by a heating treatment. The obtained magnetic nanoparticles were coated with TCPP in the presence of the amino acid L-lysine by sonication in ethanol and then refluxing for 12 h. The structural characteristics of the products were determined using FT-IR and XRD pattern. Scanning electron microscopy (SEM) images indicated uniform morphologies of the magnetic nanoparticles with an average size of 43 nm. …
Simple And Convenient Preparation Of Novel 6,8-Disubstituted Quinoline Derivatives And Their Promising Anticancer Activities, Sali̇h Ökten, Osman Çakmak, Ramazan Erenler, Önem Yüce Şahi̇n, Şaban Teki̇n
Simple And Convenient Preparation Of Novel 6,8-Disubstituted Quinoline Derivatives And Their Promising Anticancer Activities, Sali̇h Ökten, Osman Çakmak, Ramazan Erenler, Önem Yüce Şahi̇n, Şaban Teki̇n
Turkish Journal of Chemistry
A short and easy route is described for 6,8-disubstituted derivatives of quinoline and 1,2,3,4-tetrahydroquinoli- ne from 6,8-dibromoquinolines 2 and 7 by various substitution reactions. While copper-promoted substitution of 6,8-dibromide 2 produced monomethoxides 3 and 4, a prolonged reaction time mainly afforded dimethoxide 6 instead of 5, whose aromatization with DDQ and substitution reaction of dibromide 7 with NaOMe in the presence of CuI also gave rise to dimethoxide 6. Several 6,8-disubstituted quinolines were obtained by treatment of 6,8-dibromoquinoline (7) with n-BuLi followed by trapping with an electrophile [Si(Me)_3Cl, S_2(Me)_2, and DMF]. Furthermore, 7 was also converted to mono and dicyano …
Comparative Study Of Microwave-Assisted And Conventional Synthesis Of Ibuprofen-Based Acyl Hydrazone Derivatives, Ayşe Uzgören Baran
Comparative Study Of Microwave-Assisted And Conventional Synthesis Of Ibuprofen-Based Acyl Hydrazone Derivatives, Ayşe Uzgören Baran
Turkish Journal of Chemistry
A series of potential biological active acyl hydrazone derivatives containing ibuprofen moiety (compounds 4a--4p) was synthesized by the condensation of ibuprofen hydrazone with aromatic aldehydes using conventional and microwave irradiation methods. The microwave method was found to be successful with nearly the same or higher yields and shorter reaction time, and it was more environmentally friendly compared to the conventional heating method. The chemical structures of the synthesized compounds were characterized by IR, ^1H NMR, and APT-NMR spectroscopy.
Novel Flame Retardant Poly(Thiourea-Sulfone-Imide)S For High Temperature Applications: Synthesis And Characterization, Ghulam Waris, Humaira Masood Siddiqi, Lance Twyman, Rizwan Hussain, Zareen Akhter, Muhammad Saeed Butt
Novel Flame Retardant Poly(Thiourea-Sulfone-Imide)S For High Temperature Applications: Synthesis And Characterization, Ghulam Waris, Humaira Masood Siddiqi, Lance Twyman, Rizwan Hussain, Zareen Akhter, Muhammad Saeed Butt
Turkish Journal of Chemistry
The synthesis and polymerization of a novel diamine monomer, 1,1-(sulfonylbis (4,1-phenylene)) bis (thiourea) (SPT), with various aromatic dianhydrides were carried out. In addition, the fabrication of poly(thiourea-sulfone-imide)s (PTSIs) with noble thermal properties and flame retardancy was conducted. The structures of SPT and polymers were characterized by FT-IR, ^1H NMR, and ^{13}C NMR spectroscopy along with elemental analysis. Crystallinity, organosolubility, inherent viscosity, and gel permeation chromatographic measurements were taken as well. The amorphous nature was exhibited by PTSIs containing C=S and --SO_2- moieties in the backbone that were readily soluble in highly polar organic solvents. The inherent viscosities of PTSIs were …
Advances In The Chemistry Of Pyrazolopyrazoles, Rizk Elsyad Khidre, Hanan Ahmed Mohamed, Bakr Fathy Abdelwahab
Advances In The Chemistry Of Pyrazolopyrazoles, Rizk Elsyad Khidre, Hanan Ahmed Mohamed, Bakr Fathy Abdelwahab
Turkish Journal of Chemistry
Published data on the methods of preparation of pyrazolopyrazoles are summarized and described systematically. The title compounds are subdivided according to the position of fusion between the 2 pyrazole rings.
Electrochemical Properties Of 1,3-Disubstituted Methyl Methoxy Phenyl-5-Phenylformazans And Comparison With Spectral Properties, Habi̇be Tezcan, Güler Ekmekci̇, Mehmet Levent Aksu
Electrochemical Properties Of 1,3-Disubstituted Methyl Methoxy Phenyl-5-Phenylformazans And Comparison With Spectral Properties, Habi̇be Tezcan, Güler Ekmekci̇, Mehmet Levent Aksu
Turkish Journal of Chemistry
In this study, electrochemical behaviors of formazans were investigated. The compounds contained CH_3 and OCH_3 groups at the o-, m-, and p-positions of the 1-phenyl ring and an OCH_3 group at the p-position of the 3-phenyl ring. Their electrochemical behaviors, such as the number of electrons transferred, diffusion coefficients, and heterogeneous rate constants, were studied by cyclic voltammetry, ultramicrodisk electrode, and chronoamperometry. Possible mechanisms were proposed based upon the data obtained. There was a correlation between the absorption and electrochemical properties. A linear correlation was obtained between \lambda_{\max} and E_{red2} and Hammett substituent coefficients with E_{red2} and k_s values.
Synthesis And Characterization Of Ni(Ii) And Cu(Ii) Complexes Derived From Novel Phenolic Mannich Bases, Nurgün Büyükkidan, Sali̇h Özer
Synthesis And Characterization Of Ni(Ii) And Cu(Ii) Complexes Derived From Novel Phenolic Mannich Bases, Nurgün Büyükkidan, Sali̇h Özer
Turkish Journal of Chemistry
The novel phenolic Mannich bases 2,2'-(2-hydroxy-4,5- dimethylbenzylazanediyl)diethanol (1) and 2-((2-(4-(2-hydroxy-4,5- dimethylbenzyl)piperazin-1-yl)ethylamino)methyl)-4,5-dimethylphenol (2) have been synthesized in good yield by using a microwave-induced technique from 3,4-dimethylphenol and corresponding amines in the presence of formaldehyde. Metal complexes of 1 and 2 for Ni(II) (3 and 5) and for Cu(II) (4 and 6) have also been prepared and all compounds have been characterized by elemental and spectral analyses. Thermal, magnetic, and electronic studies have also been reported for metal complexes. Electronic spectra and magnetic susceptibility measurements suggested tetrahedral geometry for Ni(II) (3), square planar geometry for Cu(II) (4) complexes of 1, and octahedral …
Molecular Docking And Qsar Study On Imidazole Derivatives As 14 /Alpha -Demethylase Inhibitors, Asghar Davood, Maryam Iman
Molecular Docking And Qsar Study On Imidazole Derivatives As 14 /Alpha -Demethylase Inhibitors, Asghar Davood, Maryam Iman
Turkish Journal of Chemistry
14\alpha-Demethylase (CYP51) inhibitors have been widely used in the treatment of fungal infections. In this study, a series of imidazole derivatives with CYP51 inhibitory activity were subjected to a molecular docking study followed by quantitative structure-activity relationship (QSAR) analyses in search of the ideal physicochemical characteristics of potential CYP51 inhibitors. Desired imidazoles were built using the HyperChem program, and conformational studies were performed through a semiempirical method followed by the PM3 method. Docking study was performed using the AutoDock program on all of the compounds. Different QSAR descriptors were calculated using DRAGON, AutoDock, and HyperChem. Multilinear regression was used as …
Enaminonitriles In Heterocyclic Synthesis: Synthesis And Biological Evaluation Of Novel Indeno[2,1-B]Thiophene Derivatives, Ahmed A. Fadda, Abd El Galil M. Khalil, Eman H. Tawfik
Enaminonitriles In Heterocyclic Synthesis: Synthesis And Biological Evaluation Of Novel Indeno[2,1-B]Thiophene Derivatives, Ahmed A. Fadda, Abd El Galil M. Khalil, Eman H. Tawfik
Turkish Journal of Chemistry
No abstract provided.
Synthesis, Characterization, And Swelling Behaviors Of A Ph-Responsive Cmc-G-Poly(Aa-Co-Amps) Superabsorbent Hydrogel, Yizhe Wang, Xiaoning Shi, Wenbo Wang, Aiqin Wang
Synthesis, Characterization, And Swelling Behaviors Of A Ph-Responsive Cmc-G-Poly(Aa-Co-Amps) Superabsorbent Hydrogel, Yizhe Wang, Xiaoning Shi, Wenbo Wang, Aiqin Wang
Turkish Journal of Chemistry
New superabsorbent hydrogels were synthesized through free radical graft copolymerization of partially neutralized acrylic acid (AA) and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) onto carboxymethyl cellulose (CMC) backbones. The structure and morphology of the synthesized superabsorbent hydrogels were characterized by Fourier transform infrared spectroscopy and scanning electron microscope. The effect of the molar ratio of AMPS to AA, the APS concentration, and the CMC content on swelling ratio was optimized. The swelling properties in various pH solutions and saline solutions as well as the swelling kinetics were also evaluated. Results showed that the introduction of AMPS enhanced the swelling capacity, swelling rate, and …
Synthesis, Characterization, And Antimicrobial Activity Of Some New Phosphorus Macrocyclic Compounds Containing Pyrazole Rings, Tarik El-Sayed Ali, Salah Abdel-Aziz Abdel-Ghaffar, Kamilia Mohamed El-Mahdy, Somaia Mohamed Abdel-Karim
Synthesis, Characterization, And Antimicrobial Activity Of Some New Phosphorus Macrocyclic Compounds Containing Pyrazole Rings, Tarik El-Sayed Ali, Salah Abdel-Aziz Abdel-Ghaffar, Kamilia Mohamed El-Mahdy, Somaia Mohamed Abdel-Karim
Turkish Journal of Chemistry
A simple synthetic method is reported for the preparation of some new phosphorus macrocycles in which the pyrazole rings are appended to a phosphorus atom. The methodology is based on the cyclocondensation reaction of bis(4-formylpyrazolyl) phosphine oxide(1a, 1b) with nitrogen nucleophiles that contain active terminal amino groups. The antimicrobial activities of the synthesized compounds were assayed.
Removal Of Cr(Iii) And Cu(Ii) Using Oly(2-Chloroaniline)/Polyvinylidenefluoride Composite Cation-Exchange Membranes By Donnan Dialysis, Esengül Kir, Sabri̇ye Perçi̇n Özkorucuklu, Tuğba Sardohan Köseoğlu, Esi̇n Karamizrak
Removal Of Cr(Iii) And Cu(Ii) Using Oly(2-Chloroaniline)/Polyvinylidenefluoride Composite Cation-Exchange Membranes By Donnan Dialysis, Esengül Kir, Sabri̇ye Perçi̇n Özkorucuklu, Tuğba Sardohan Köseoğlu, Esi̇n Karamizrak
Turkish Journal of Chemistry
P2ClAn/PVDF composite membranes were prepared utilizing cation-exchange groups in the PVDF (polyvinylidenefluoride) membrane matrix by casting method. The poly(2-chloroaniline) (P2ClAn) was chemically synthesized with different dopant anions such as o-aminobenzene sulfonic acid (ABS) and sodium dodecyl sulfate (SDS). P2ClAn/PVDF membranes were extensively characterized for their surface morphology, thickness, ion-exchange capacity, SEM, AFM, and FTIR-ATR measurements. The SEM, AFM and FTIR-ATR pictures, comparing the original PVDF membrane support sheet to P2ClAn/PVDF composite membranes, indicate that the morphologies of the membranes are different. The membrane potential measurements were performed in various electrolyte solutions in order to observe the selectivity and stability of …
Synthesis And Characterization Of Thermally Stable Camphor-Based Polyimide--Clay Nanocomposites, Murat Yi̇ği̇t, Turgay Seçki̇n, Beyhan Yi̇ği̇t, Süleyman Köytepe
Synthesis And Characterization Of Thermally Stable Camphor-Based Polyimide--Clay Nanocomposites, Murat Yi̇ği̇t, Turgay Seçki̇n, Beyhan Yi̇ği̇t, Süleyman Köytepe
Turkish Journal of Chemistry
A new monomer was prepared from (1R,3S)-(+)-camphoric acid. Novel polyimide and polyimide--clay hybrid composites were developed from one-pot condensation reactions of this monomer and pyromellitic dianhyride. Polyimide-montmorillonite nanocomposites were prepared from solution of polyimide and with different weight percentages (1, 5, 10 wt %) of organo-modified montmorillonite (OM-MMT) using N-methyl-2-pyrrolidone (NMP) as aprotic solvent. The reactive organoclay was formed by using hexadecylpyridinium chloride as a swelling agent for silicate layers of montmorillonite. The polyimide--clay composites films (PI--MMT) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD). All composites were subjected to differential scanning calorimetry …
Antimicrobial Activity And Chemical Composition Of The Essential Oils Of Mosses (Hylocomium Splendens (Hedw.) Schimp. And Leucodon Sciuroides (Hedw.) Schwägr.) Growing In Turkey, Tayyi̇be Beyza Cansu, Büşra Yayli, Turan Özdemi̇r, Nevzat Batan, Şengül Alpay Karaoğlu, Nuretti̇n Yayli
Antimicrobial Activity And Chemical Composition Of The Essential Oils Of Mosses (Hylocomium Splendens (Hedw.) Schimp. And Leucodon Sciuroides (Hedw.) Schwägr.) Growing In Turkey, Tayyi̇be Beyza Cansu, Büşra Yayli, Turan Özdemi̇r, Nevzat Batan, Şengül Alpay Karaoğlu, Nuretti̇n Yayli
Turkish Journal of Chemistry
In the present work, the volatiles of mosses [Hylocomium splendens (Hedw.) Schimp. (Hylocomiaceae) and Leucodon sciuroides (Hedw.) Schwägr. (Leucodontaceae)] have been investigated by GC-FID and GC/MS. Fifty-eight compounds in the oil of H. splendens, representing 75.4%, and 41 compounds in the oil of L. sciuroides, representing 87.6%, were identified. The major components were found to be \beta-pinene (11.6%) and \alpha-pinene (8.9%) in the oil of H. splendens, and nonanal (26.8%) and heptanal (13.7%) in the oil of L. sciuroides. The essential oil of H. splendens was rich in monoterpenes (30.8%), and aldehydes (49.9%) were the major constituents in the oil …
Synthesis And Evaluation Of Acetylcholineesterase Inhibitory Potential And Antioxidant Activity Of Benzothiazine Derivatives, Durre Shahwar, Uzma Sana, Naeem Ahmad
Synthesis And Evaluation Of Acetylcholineesterase Inhibitory Potential And Antioxidant Activity Of Benzothiazine Derivatives, Durre Shahwar, Uzma Sana, Naeem Ahmad
Turkish Journal of Chemistry
The aim of the present study was to synthesize and characterize benzothiazine derivatives prepared by using 2-aminothiophenol and saccharine and in vitro screen their enzyme inhibition and antioxidant potential. Nine different derivatives were prepared and their structures were confirmed by spectral studies (EIMS, ^1 H and ^{13}C NMR). Enzyme inhibition potential of the synthesized compounds was evaluated by Ellman's method, while antioxidant activity was determined by DPPH and FRAP assays. All the derivatives showed remarkable activity against acetylcholine esterase with IC_{50} values in the range of 35.9--122.0 \mu M. All other derivatives, except compound 4a, were inactive towards DPPH radical. …
An Efficient Ligand-Free Method For The Transfer Hydrogenation Of Ketones And Aldehydes Catalyzed By Different Complexes, Sedat Yaşar, Suzan Çeki̇rdek, Ni̇lay Akkuş Taş, Semi̇ha Yildirim, İsmai̇l Özdemi̇r
An Efficient Ligand-Free Method For The Transfer Hydrogenation Of Ketones And Aldehydes Catalyzed By Different Complexes, Sedat Yaşar, Suzan Çeki̇rdek, Ni̇lay Akkuş Taş, Semi̇ha Yildirim, İsmai̇l Özdemi̇r
Turkish Journal of Chemistry
A very efficient ligand-free method was developed for the transfer hydrogenation of ketones and aldehydes catalyzed by different metal complexes. With this catalytic system, the catalytic performance and catalytic stability of different Ir, Ru, and Pd complexes were more favorable than those of the previously reported systems for transfer hydrogenation. This ligand-free catalytic system showed good stability and excellent activity even with lower catalyst concentrations for the ketones and aldehydes tested.
Synthesis And Antimicrobial Investigation Of Some 5h-Pyridazino[4,5-B]Indoles, İlker Avan, Alaetti̇n Güven, Kiymet Güven
Synthesis And Antimicrobial Investigation Of Some 5h-Pyridazino[4,5-B]Indoles, İlker Avan, Alaetti̇n Güven, Kiymet Güven
Turkish Journal of Chemistry
Synthesis and in vitro antimicrobial activities are reported for a series of 1,3,5-substituted 4-oxo-3,4-dihydro-5H-pyridazino[4,5-b]indole derivatives. Corresponding pyridazino[4,5-b]indoles were prepared from ethyl 3-formyl-1H-indole-2-carboxylate precursors and the functional group in question was installed with hydrazine and its derivatives. The purity and primary structures of pyridazino[4,5-b]indole were confirmed by IR, ^1 H NMR, and ^{13}C NMR spectroscopy and elemental analyses. All of the indoles were tested for in vitro antimicrobial activity against 8 isolates of bacteria and a fungus including Staphylococcus aureus NRRL B-767, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, Proteus vulgaris NRRL-B123, Salmonella typhimurium NRRL B-4420, Bacillus subtilis NRRL 744, …
Application Of Experimental Design On Determination Of Aluminum Content In Saline Samples By Adsorptive Cathodic Stripping Voltammetry, Si̇nan Yilmaz, Betül Öztürk, Durmuş Özdemi̇r, Ahmet Emi̇n Eroğlu, Fatma Ni̇l Ertaş
Application Of Experimental Design On Determination Of Aluminum Content In Saline Samples By Adsorptive Cathodic Stripping Voltammetry, Si̇nan Yilmaz, Betül Öztürk, Durmuş Özdemi̇r, Ahmet Emi̇n Eroğlu, Fatma Ni̇l Ertaş
Turkish Journal of Chemistry
Adsorptive cathodic stripping voltammetric determination of aluminum at ng mL^{-1} levels in salt samples based on the metal complexation with Calcon (1-(2-hydroxynaphthylazo)-2 naphthol-4-sulfonic acid) and the subsequent adsorptive deposition onto a hanging mercury drop electrode was studied. Central composite design was used as a design method. Several chemical and instrumental parameters (pH, ligand concentration, deposition time, deposition potential, and complexing time) were involved in the experimental design. Analytical parameters such as repeatability, linearity, and accuracy were also investigated and the detection limit was found as 0.32 ng mL^{-1}.
Theoretical Study On The Addition Reaction Between Propadienylidene And Methyleneimine, Mengyuan Wang, Yungang Chen, Shanshan Ding, Yingde Wang, Qianchao Cao, Xiaojun Tan, Jinsong Gu
Theoretical Study On The Addition Reaction Between Propadienylidene And Methyleneimine, Mengyuan Wang, Yungang Chen, Shanshan Ding, Yingde Wang, Qianchao Cao, Xiaojun Tan, Jinsong Gu
Turkish Journal of Chemistry
The reaction mechanism between propadienylidene and methyleneimine was systematically investigated employing the second-order Møller--Plesset perturbation theory (MP2) method with the 6 -- 31 + G* basis set. Geometry optimization, vibrational analysis, and energy property of the involved stationary points on the potential energy surface were calculated. The energies of the different species were corrected by single point energy calculations at the CCSD (T) // MP2 / 6 -- 31 + G* level. From the surface energy profile, one important initial intermediate characterized by a 3-membered ring structure was located via a transition state firstly. After that, 3 different products possessing …
Spectral, Electrochemical, Luminescence, And Dye-Sensitized Solar Cell Studies Of Mono And D-F Hetero Binuclear Cryptates, Arunachalam Vijayaraj, Raju Prabu, Ranganathan Suresh, Subbaiah Manoharan, Sambandam Anandan, Vengidusamy Narayanan
Spectral, Electrochemical, Luminescence, And Dye-Sensitized Solar Cell Studies Of Mono And D-F Hetero Binuclear Cryptates, Arunachalam Vijayaraj, Raju Prabu, Ranganathan Suresh, Subbaiah Manoharan, Sambandam Anandan, Vengidusamy Narayanan
Turkish Journal of Chemistry
Mono and hetero binuclear cryptates, [Gd(III)ML]^+ [M = VO(IV), Co(II), Ni(II), Cu(II)], were synthesized by a 2-step method. The ligand L represents the deprotonated anionic cryptate obtained by the 2+3 condensation of tris-(2-aminoethyl)amine with 2,6-diformyl-4-nitrophenol. The complexes were characterized by elemental analysis, spectral, magnetic, and electrochemical studies. Fluorescence of Gd(III) ion in the cavity was quenched by the encapsulated Cu(II) and Ni(II) ions. [GdCoL(NO_3)]^+ cryptate had a high lifetime value compared to other cryptates. The cyclic voltammogram showed that the reduction potential values of [Gd(M)L] M = VO(IV), Co(II), Ni(II), and Cu(II) complexes were in the following order: Cu(II) > Ni(II) …
C_2-Symmetric Chiral Diamine Ligands For Enantiomeric Recognition Of Amino Acid Esters And Mandelic Acid By Proton Nmr Titration Method, Hayri̇ye Aral, Tarik Aral, Mehmet Çolak, Berri̇n Zi̇yadanoğullari, Recep Zi̇yadanoğullari
C_2-Symmetric Chiral Diamine Ligands For Enantiomeric Recognition Of Amino Acid Esters And Mandelic Acid By Proton Nmr Titration Method, Hayri̇ye Aral, Tarik Aral, Mehmet Çolak, Berri̇n Zi̇yadanoğullari, Recep Zi̇yadanoğullari
Turkish Journal of Chemistry
Two novel C_2-symmetric chiral diamines containing \alpha -phenylethyl and \alpha -(1-naphthyl)ethyl chiral subunits were prepared with quantitative yields. Enantiomeric recognition properties of these simple structured diamine ligands towards D- and L-amino acid esters and D- and L-mandelic acid were examined by the ^1H NMR titration method. These ligands exhibited strong complexation (with K_f up to 2481 M^{-1}) and good enantioselectivity (up to K_L/K_D = 4.08) towards the mandelic acid enantiomers. The results show that simple structured and easily accessible acyclic C_2-symmetrical compounds can also be used for enantiomeric recognition of racemic amino acids and mandelic acid in addition to complex …
Environmentally Green Synthesis Of Thioformamide Derivatives, Ali Ramazani, Sang Woo Joo, Fatemeh Zeinali Nasrabadi
Environmentally Green Synthesis Of Thioformamide Derivatives, Ali Ramazani, Sang Woo Joo, Fatemeh Zeinali Nasrabadi
Turkish Journal of Chemistry
Reactions of isocyanides with thioacids in water proceeded smoothly at room temperature and in neutral conditions to afford thioformylamide and thioformamide derivatives in high yields. The reaction proceeded smoothly and cleanly under mild conditions and no side reactions were observed.
Potentiometric Study Of Equilibrium Constants Of A Novel Triazine--Thione Derivative And Its Stability Constants With Hg^{2+}, Cu^{2+}, Ni^{2+}, Pb^{2+}, And Zn^{2+} Metal Ions In Ethanol And Water Mixed, Fati̇h Polat, Hasan Atabey, Hayati̇ Sari, Alaaddi̇n Çukurovali
Potentiometric Study Of Equilibrium Constants Of A Novel Triazine--Thione Derivative And Its Stability Constants With Hg^{2+}, Cu^{2+}, Ni^{2+}, Pb^{2+}, And Zn^{2+} Metal Ions In Ethanol And Water Mixed, Fati̇h Polat, Hasan Atabey, Hayati̇ Sari, Alaaddi̇n Çukurovali
Turkish Journal of Chemistry
The deprotonation constants of 5-hydroxy-5,6-di-pyridin-2-yl-4,5-dihydro-2H-[1,2,4] triazine-3-thione (HPT) and the stability constants of its Hg^{2+}, Ni^{2+}, Cu^{2+}, Pb^{2+}, and Zn^{2+} ion complexes were studied in 20% ethanol and water mixed at 25 \pm 0.1 °C and ionic strength (I) of 0.1 M supported by NaCl. Four pK_a values of HPT were determined: 3.58, 6.30, 9.23, and 9.69. In various pH conditions, the different complex forms were formulated as ML, MHL, MH_2L, MH_3L, MH_4L, and MH_{-2}L between Hg^{2+}, Ni^{2+}, Cu^{2+}, Pb^{2+}, and Zn^{2+} ions and HPT. According to the potentiometric and spectrophotometric results, the HPT and Hg^{2+} combination formed a selective and …