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Articles 1621 - 1650 of 2720
Full-Text Articles in Chemistry
Isolation Of Bis(1,4-Diphenyl-1,4-Bis(2-Pyridyl)-2,3-Diaza-1,3-Butadiene) Disilver With Bridging (N-N) Dinucleating Subunits: Formation Of A 6-Membered Chelate Ring, Amitabha Datta, Neerish Revaprasadu
Isolation Of Bis(1,4-Diphenyl-1,4-Bis(2-Pyridyl)-2,3-Diaza-1,3-Butadiene) Disilver With Bridging (N-N) Dinucleating Subunits: Formation Of A 6-Membered Chelate Ring, Amitabha Datta, Neerish Revaprasadu
Turkish Journal of Chemistry
A novel Ag(I) dinuclear complex {[(C_6H_5)(C_5H_4N)-C=N-N=C- (C_5H_4N)(C_6H_5)]Ag}_2.ClO_4(ClO_4) (1/2CH_3CN) (1) that was derived under mild conditions, during the course of combination of AgClO_4 with a polymorphic azine ligand, 1,4-diphenyl-1,4-bis(2-pyridyl)-2,3- diaza-1,3-butadiene (L) (condensed product of phenyl 2-pyridyl ketone and hydrazine monohydrate) is reported. The aforementioned complex is based on a central rotationally flexible diazine subunit (N-N). The azine ligand, L, having the N_2 dinucleating fragment, provides a coordination focus for pairs of metal centres and ultimately leads to the formation of a 6-membered chelate ring in 1.
Composition Of The Essential Oils Of Pinus Nigra Arnold From Turkey, Ekrem Sezi̇k, Osman Üstün, Bülent Demi̇rci̇, Kemal Hüsnü Can Başer
Composition Of The Essential Oils Of Pinus Nigra Arnold From Turkey, Ekrem Sezi̇k, Osman Üstün, Bülent Demi̇rci̇, Kemal Hüsnü Can Başer
Turkish Journal of Chemistry
Essential oil composition of the needles of Pinus nigra Arnold collected from different localities in Turkey was investigated by GC and GC/MS. The main components in the oils were \alpha-pinene, \beta-pinene, \beta-caryophyllene, and germacrene D.
Synthesis And Antimicrobial Activities Of 2-(5-Mercapto)-1,3-Oxadiazol-2-Ylmethyl-1,2,4-Triazol-3-One Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hakan Bektaş, Şengül Alpay Karaoğlu, Deni̇z Şahi̇n
Synthesis And Antimicrobial Activities Of 2-(5-Mercapto)-1,3-Oxadiazol-2-Ylmethyl-1,2,4-Triazol-3-One Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hakan Bektaş, Şengül Alpay Karaoğlu, Deni̇z Şahi̇n
Turkish Journal of Chemistry
The synthesis of 4-amino-2-[(5-mercapto-1,3,4-oxadiazol-2- yl)methyl]-5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (2) and 4-amino-2-[(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)methyl]- 5-(4-methylphenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (5) was performed starting from 2-[4-amino-3-(4-methylphenyl)-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl]acetohydrazide (1). The treatment of 2 and 5 with 4-fluorobenzaldehyde (for 8) or salicylaldehyde (for 6) afforded the corresponding Schiff bases (6 and 8). The condensation of 5 with phenacyl bromide produced 4-amino-5-(4-methylphenyl)-2- [(6-phenyl-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazin-3-yl)methyl]- 2,4-dihydro-3H-1,2,4-triazol-3-one (7). The alkylation of 2 and 8 was carried out by using methyl iodide in basic media. Compounds 3 and 10a,b were prepared by aminoalkylation of 2 and 8 with 4-fluorophenyl piperazine, morpholine, or 4-methyl piperazine in the presence of formaldehyde. The synthesized compounds were screened for their antimicrobial activities …
An Efficient One-Pot Synthesis Of Dihydropyrimidinones Catalyzed By Zirconium Hydrogen Phosphate Under Solvent-Free Conditions, Mustafa Küçüki̇slamoğlu, Şenol Beşoluk, Mustafa Zengi̇n, Mustafa Arslan, Mehmet Nebi̇oğlu
An Efficient One-Pot Synthesis Of Dihydropyrimidinones Catalyzed By Zirconium Hydrogen Phosphate Under Solvent-Free Conditions, Mustafa Küçüki̇slamoğlu, Şenol Beşoluk, Mustafa Zengi̇n, Mustafa Arslan, Mehmet Nebi̇oğlu
Turkish Journal of Chemistry
A simple, efficient, and practical procedure for the Biginelli reaction using zirconium hydrogen phosphate [Zr(H_2PO_4)_2] as a novel solid acid catalyst is described under solvent-free conditions in high yields. The catalyst exhibited remarkable reactivity and it is reusable.
Preparation And Characterization Of Anticancer Drug-Loaded Implantable Plga Microparticles, Meltem Çeti̇n, İmran Vural, Alptuğ Ati̇la, Yücel Kadioğlu
Preparation And Characterization Of Anticancer Drug-Loaded Implantable Plga Microparticles, Meltem Çeti̇n, İmran Vural, Alptuğ Ati̇la, Yücel Kadioğlu
Turkish Journal of Chemistry
This article describes the preparation and characterization of anticancer drug-loaded poly(lactide-co-glycolide) (PLGA) microparticles. PLGA microparticles loaded with doxorubicin HCl (DOX) were prepared via o/w emulsion solvent evaporation. The release characteristics, encapsulation efficiency, size, and morphology of the PLGA microparticles were also determined. A cytotoxicity test was performed by using Glioma RG2 cancer cells to investigate the cytotoxicity of DOX-loaded PLGA microparticles. The DOX-loaded PLGA microparticles had an average diameter of 500 \pm 9 nm. The DOX encapsulation efficiency and drug loading were 22.75% and 0.78%, respectively. DOX-loaded PLGA microparticles displayed a significant cytotoxicity toward the RG2 cells as compared to …
Synthesis And Antimicrobial Activities Of Some New Biheterocyclic Compounds Containing 1,2,4-Triazol-3-One And 1,3,4-Thiadiazole Moieties, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Hakan Bektaş, Hacer Bayrak, Şengül Alpay Karaoğlu
Synthesis And Antimicrobial Activities Of Some New Biheterocyclic Compounds Containing 1,2,4-Triazol-3-One And 1,3,4-Thiadiazole Moieties, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Hakan Bektaş, Hacer Bayrak, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
2-(4-Amino-3-(4-chlorophenyl)-5-oxo-4,5--dihydro-1H-1,2,4-triazol- 1-yl)-N'-[(2,6-dihalogenophenyl)-methylene]acetohydrazides (3a,b) was obtained via the formation of 2-(4-amino-3-(4-chlorophenyl)-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl)acetohydrazide (2), which was obtained starting from 4-amino-5-(4-chlo\-rophenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (1) in 2 steps. 2-{[4-amino-3-(4-chlorophenyl)-5-oxo-4,5--dihydro-1H- 1,2,4-triazol-1-yl]acetyl}-N-phenylhydra-zine carbothioamide (4), which was prepared starting from 2, was converted to the corresponding 1,3,4-thiadiazole derivative (5) in acidic media. Moreover, the basic treatment of 4 resulted in the formation of 4-amino-5-(4-chlorophenyl)- 2-[(4-phenyl-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)methyl]-2,4- dihydro-3H-1,2,4-triazol-3-one (7). The reactions of compounds 5 and 7 with methyl iodide in the presence of sodium ethoxide afforded the corresponding N-methyl (6) and S-methyl (8) derivatives, respectively. The synthesis of Mannich bases (10a and 10b) was performed from the reaction of 7 with …
A Calorimetric Study Of The Interaction Of Silver Ions With Jack Bean Urease, Ali Akbar Saboury, Elahe Poorakbar, Gholamreza Rezaei-Behbehani
A Calorimetric Study Of The Interaction Of Silver Ions With Jack Bean Urease, Ali Akbar Saboury, Elahe Poorakbar, Gholamreza Rezaei-Behbehani
Turkish Journal of Chemistry
A thermodynamic study of silver ions by jack bean urease (JBU) was carried out at 2 temperatures, 27 and 37 °C, in Tris buffer (30 mM; pH 7.0) using isothermal titration calorimetry (ITC). There was a set of 12 identical and noninteracting binding sites for the silver ions. The intrinsic dissociation equilibrium constant and the molar enthalpy of binding were 185 \mu M and -16.7 kJ mol^{-1} at 27 °C, and 229 \mu M and -16.3 kJ mol^{-1} at 37 °C, respectively. The molar entropy of binding was +15.7 J K^{-1} mol^{-1} at 27 °C and +17.1 J K^{-1} mol^{-1} …
Synthesis And Characterisations Of Some New 2,4-Dihydro-[1,2,4]- Triazol-3-One Derivatives And X-Ray Crystal Structures Of 4-(3-Phenylallylideneamino)-5-Thiophen-2-Yl-Methyl-2,4-Dihydro-[1,2,4]Triazol-3-One, Kemal Sancak, Yasemi̇n Ünver, Canan Kazak, Esra Düğdü, Burcu Arslan
Synthesis And Characterisations Of Some New 2,4-Dihydro-[1,2,4]- Triazol-3-One Derivatives And X-Ray Crystal Structures Of 4-(3-Phenylallylideneamino)-5-Thiophen-2-Yl-Methyl-2,4-Dihydro-[1,2,4]Triazol-3-One, Kemal Sancak, Yasemi̇n Ünver, Canan Kazak, Esra Düğdü, Burcu Arslan
Turkish Journal of Chemistry
Compounds 2 were synthesised via the reaction of 4-amino-5-thiophen-2-yl-methyl-2,4-dihydro-[1,2,4]-triazol-3-one (1) with aldehydes. Compounds 3 and 4 were obtained from compounds 2 with bromo acetophenone and ethyl bromoacetate, respectively. The synthesis of compounds 2, 3, and 4 and crystal structure of compound 2a are being reported. The molecular structures were identified by IR, ^1H-NMR, ^{13}C-NMR, MS, and elemental analyses. Compound 2a crystallises in the monoclinic P 2_1/n space group, with a = 6.565(5) Å, b = 18.278(5) Å, c = 13.8166(18) Å, \beta = 96.227(5)°, V = 1553.6(14) Å^3, Z = 4. The newly compounds synthesised were screened for their antibacterial …
Electrochemical Impedance Spectroscopic Studies Of The Passive Layer On The Surface Of Copper As A Function Of Potential, Amtul Naseer, Athar Khan
Electrochemical Impedance Spectroscopic Studies Of The Passive Layer On The Surface Of Copper As A Function Of Potential, Amtul Naseer, Athar Khan
Turkish Journal of Chemistry
Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were used to investigate the oxide layer formed on a copper disc electrode and the changes that took place when treated potentiostatically in the range of -0.3 V to 0.9 V in buffer of pH 8.5. The response of an electrode using EIS, initially at equilibrium, to an applied potential was then modeled with equivalent circuits, proposed for different potential regions that completely illustrated the Cu/oxide/electrolyte systems and their properties in terms of 2 interfaces. Criterion for the applicability of equivalent circuit models was discussed. Changes in the film/metal interface as a …
Chemical Composition And Antimicrobial Activity Of The Essential Oils Of Mosses (Tortula Muralis Hedw., Homalothecium Lutescens (Hedw.) H. Rob., Hypnum Cupressiforme Hedw., And Pohlia Nutans (Hedw.) Lindb.) From Turkey, Osman Üçüncü, Tayyi̇be Beyza Cansu, Turan Özdemi̇r, Şengül Alpay Karaoğlu, Nuretti̇n Yayli
Chemical Composition And Antimicrobial Activity Of The Essential Oils Of Mosses (Tortula Muralis Hedw., Homalothecium Lutescens (Hedw.) H. Rob., Hypnum Cupressiforme Hedw., And Pohlia Nutans (Hedw.) Lindb.) From Turkey, Osman Üçüncü, Tayyi̇be Beyza Cansu, Turan Özdemi̇r, Şengül Alpay Karaoğlu, Nuretti̇n Yayli
Turkish Journal of Chemistry
The essential oils of mosses [Tortula muralis Hedw. (Pottiaceae), Homalothecium lutescens (Hedw.) H. Rob. (Brachytheciaceae), Hypnum cupressiforme Hedw. (Hypnaceae), and Pohlia nutans (Hedw.) Lindb. (Mniaceae)] were investigated by means of GC-FID/MS techniques. The major components were nonanal (18.3%) and tetradecanol (4.3%) in the oil of T. muralis, nonanal (36.8%) and tricosane (6.5%) in the oil of H. lutescens, nonanal (12.5%) and 2E-tetradecen-1-ol (6.9%) in the oil of H. cupressiforme, and nonanal (7.8%) and 2E-tetradecen-1-ol (7.1%) in the oil of P. nutans. The essential oils of T. muralis, H. lutescens, H. cupressiforme, and P. nutans were rich as in non-terpenoid components …
Determination Of Ceftriaxone, Ceftizoxime, Paracetamol, And Diclofenac Sodium By Capillary Zone Electrophoresis In Pharmaceutical Formulations And In Human Blood Serum, Amber Solangi, Saima Memon, Arfana Mallah, Najma Memon, Muhammad Yar Khuhawar, Muhammad Iqbal Bhanger
Determination Of Ceftriaxone, Ceftizoxime, Paracetamol, And Diclofenac Sodium By Capillary Zone Electrophoresis In Pharmaceutical Formulations And In Human Blood Serum, Amber Solangi, Saima Memon, Arfana Mallah, Najma Memon, Muhammad Yar Khuhawar, Muhammad Iqbal Bhanger
Turkish Journal of Chemistry
A simple and fairly fast capillary zone electrophoresis method has been developed for the determination and separation of ceftriaxone, ceftizoxime, paracetamol, and diclofenac sodium in a mixture, in pharmaceutical formulations, and in blood serum. A 50 mM sodium tetraborate background electrolyte solution (pH 9.0) was found to be suitable for separation of all the drugs. An uncoated fused-silica capillary of a total length of 57 cm (effective length 50 cm) was used for separation. All the analytes were completely separated within 8.0 min at an applied voltage of 30 kV and detection was performed at 214 nm .Validation of the …
Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hacer Bayrak, Hakan Bektaş, Şengül Alpay Karaoğlu
Synthesis And Antimicrobial Activities Of Some New 1,2,4-Triazole Derivatives, Nesli̇han Demi̇rbaş, Ahmet Demi̇rbaş, Hacer Bayrak, Hakan Bektaş, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
The synthesis of ethyl [3-(cyanomethyl)-5-alkyl-4H-1,2,4-triazol- 4-yl]carbamates (2a-d) was performed starting from ethyl 2-[ethoxy(4- (aryl)methylene]hydrazinecarboxylates (1a, 1b). The treatment of 2a with thiosemicarbazide afforded ethyl [3-[(5-amino-1,3,4-thiadiazol- 2-yl)methyl]-5-(4-nitrophenyl)-4H-1,2,4-triazol-4-yl]carbamates (3a), whereas compound 2b produced 5-{[4-amino-5-(4-methylphenyl)- 4H-1,2,4-triazol-3-yl]methyl}-1,3,4-thiadiazol-2-amine (3b) in the same reaction conditions. The treatment of tert-butyl 2-[2-(4-chlorophenyl)-1-ethoxyethylidene]hydrazinecarboxylate (5) with malonohydrazide or cyanoacethydrazide gave the corresponding 1,2,4-triazol-ylcarbamate derivatives (6 or 9); then the hydrolysis of these compounds resulted in the formation of 3-{[4-amino-5-(4- chlorobenzyl)-4H-1,2,4-triazol-3-yl]methyl}-5-(4-chlorobenzyl)-4H- 1,2,4-triazol-4-amine (7) and [4-amino-5-(4-chlorobenzyl)-4H- 1,2,4-triazole-3-yl]acetonitrile (10), respectively. The synthesis of the Schiff base derivatives 3-(4-chlorobenzyl)-5-{[5-(4-chloroben- zyl)-4-[(2-hydroxyphenyl-methylene)amino]-4H-1,2,4-triazol-3-yl]methyl} -N-(2-hydroxyphenylmethylene)-4H-1,2,4-triazol-4-amine (8), and (5-(4-chlorobenzyl)-4-{[(2,6-dichlorophenyl)methylene]amino}-4H-1,2,4- triazol-3-yl)acetonitrile (12) was performed from the reaction of compounds 7 …
Interference Elimination Studies During The Determination Of Trace Elements In Cow Liver Using Differential Pulse Polarography, Ümmi̇han T. Yilmaz, Güler Somer
Interference Elimination Studies During The Determination Of Trace Elements In Cow Liver Using Differential Pulse Polarography, Ümmi̇han T. Yilmaz, Güler Somer
Turkish Journal of Chemistry
The liver is known to accumulate many trace elements; thus it is very important to determine their level in a sensitive way. The objective of this study was to develop a simple method for the simultaneous determination of trace elements in cow liver in which the elimination of interference can be accomplished. It was observed that Cd, Pb, Zn, and Cu ions could not be determined correctly in the presence of Se(IV), because of interference of Se. It was shown that this interference could be eliminated by using pH 8.5 NaAc electrolyte. In this medium first Cd and Zn were …
Synthesis, Structural Determination, And Biological Activity Of New 7-Hydroxy-3-Pyrazolyl-4h-Chromen- 4-Ones And Their O-\Beta-D-Glucosides, Kishor Hatzade, Vijay Taile, Pravin Gaidhane, Vishwas Ingle
Synthesis, Structural Determination, And Biological Activity Of New 7-Hydroxy-3-Pyrazolyl-4h-Chromen- 4-Ones And Their O-\Beta-D-Glucosides, Kishor Hatzade, Vijay Taile, Pravin Gaidhane, Vishwas Ingle
Turkish Journal of Chemistry
A convenient route to synthesize some new medicinally important 7-hydroxy-3-pyrazolyl chromones (3a-i) is described. The interaction of 7-hydroxy-3-formyl chromone (1) with various substituted acetophenones and further cyclization with hydrazine hydrate in an aprotic solvent followed by condensation with 2, 3, 4, 6-tetra-o-acetyl-\alpha-dglucopyranosyl bromide afforded 2, 3, 4, 6-tetra-o-acetyl-\beta-d-glucopyranosyloxy-3-(3-aryl-1H-pyrazol-5- yl)-4H-chromen-4-ones (4a-i). Later deacetylation with anhydrous zinc acetate in methanol gave 7-o-\beta-d-glucopyranosyloxy-3-(3-aryl- 1H-pyrazol-5-yl)-4H-chromen-4-ones (5a-i). These compounds were evaluated for their in vitro antimicrobial and anti-oxidant activity. The structures of these newly synthesized o-glucosides were established by IR, NMR, mass spectra, elemental analysis, and chemical analysis.
Synthesis And Characterisation Of Vanadium(Iii) Complexes Of Biphenylphenols, Neeraj Sharma, Maridula Thakur, S C. Chaudhry
Synthesis And Characterisation Of Vanadium(Iii) Complexes Of Biphenylphenols, Neeraj Sharma, Maridula Thakur, S C. Chaudhry
Turkish Journal of Chemistry
The vanadium(III) complexes of composition [VCl_{3-n}(OAr^{1,2})_n.(THF)_2] (OAr^1 = 2-phenylphenoxo and OAr^2 = 4-phenylphenoxo, THF = tetrahydrofuran; n = 1 /to 3) were prepared by in situ reaction of VCl_3.(THF)_3 with sodium salt of respective phenols in tetrahydrofuran. The complexes were characterised by elemental analysis, molar conductance, FTIR, UV-Vis, and FAB-mass spectral and magnetic studies. The thermal behaviour of some of the complexes was studied by TG-DTA. The dinuclear phenoxy bridged octahedral structures for the complexes were inferred from the spectral and magnetic studies.
Electro-Oxidation Of Some Non-Steroidal Anti-Inflammatory Drugs On An Alumina Nanoparticle-Modified Glassy Carbon Electrode, Mahla Tabeshnia, Hossein Heli, Ali Jabbari, Ali A. Moosavi-Movahedi
Electro-Oxidation Of Some Non-Steroidal Anti-Inflammatory Drugs On An Alumina Nanoparticle-Modified Glassy Carbon Electrode, Mahla Tabeshnia, Hossein Heli, Ali Jabbari, Ali A. Moosavi-Movahedi
Turkish Journal of Chemistry
The electro-oxidation of mefenamic acid, diclofenac, and indomethacin on glassy carbon and alumina nanoparticle-modified glassy carbon electrodes in a phosphate buffer solution at physiological pH was studied. The techniques of cyclic voltammetry, chronoamperometry, impedance spectroscopy, and steady state polarization measurements were applied. The drugs were irreversibly oxidized on bath electrodes via an anodic peak and the process was controlled by diffusion in the bulk of solution. Alumina nanoparticles increased the oxidation current, and lowered the peak and onset potentials. As such, alumina nanoparticles had an electrocatalytic effect, both kinetically and thermodynamically. The kinetic parameters of heterogeneous electron transfer and diffusion …
An Investigation Of Energy Transfer Between Coumarin 35 And Xanthene Derivatives In Liquid Medium, Mahmut Toprak, Mustafa Arik
An Investigation Of Energy Transfer Between Coumarin 35 And Xanthene Derivatives In Liquid Medium, Mahmut Toprak, Mustafa Arik
Turkish Journal of Chemistry
The energy transfer between coumarin 35 (C35) and pyronin compounds, which are xanthene derivatives, i.e. pyronin B (PyB) and pyronin Y (PyY), in methanol was investigated at room temperature by using steady-state absorption, emission, and time-resolved fluorescence spectroscopy. Fluorescence energy transfer rate constants (k_T) and critical radius (R_0) were determined for C35-PyB and C35-PyY molecular pairs in methanol. The obtained values of k_T and R_0 indicated that the dipole-dipole interaction between C35-PyB and C35-PyY molecular pairs accounted for the energy transfer mechanism. The energy transfer efficiency and the distance between the donor and acceptor (r) were also calculated for donor-acceptor …
Silica Supported Polyphosphoric Acid (Ppa-Sio_2): An Efficient And Reusable Heterogeneous Catalyst For The One-Pot Synthesis Of \Alpha -Amino Phosphonates, Malek Taher Maghsoodlou, Sayyed Mostafa Habibi-Khorassani, Reza Heydari, Nourollah Hazeri, Seyed Sajad Sajadikhah, Mohsen Rostamizadeh, Leila Keishams
Silica Supported Polyphosphoric Acid (Ppa-Sio_2): An Efficient And Reusable Heterogeneous Catalyst For The One-Pot Synthesis Of \Alpha -Amino Phosphonates, Malek Taher Maghsoodlou, Sayyed Mostafa Habibi-Khorassani, Reza Heydari, Nourollah Hazeri, Seyed Sajad Sajadikhah, Mohsen Rostamizadeh, Leila Keishams
Turkish Journal of Chemistry
An efficient green protocol is described for the preparation of \alpha -amino phosphonates, employing a one-pot three-component condensation reaction between aldehydes, amines, and trialkyl phosphites in the presence of PPA-SiO_2 under solvent-free conditions at 80 °C. The present procedure offer advantages such as high to excellent yields, short reaction time, inexpensiveness, recovery, and reusability of catalyst.
Synthesis And Characterization Of Gold Nanoparticles Supported On Zinc Oxide Via The Deposition-Precipitation Method, Hanani Yazid, Rohana Adnan, Shafida Abdul Hamid, Muhammad Akhyar Farrukh
Synthesis And Characterization Of Gold Nanoparticles Supported On Zinc Oxide Via The Deposition-Precipitation Method, Hanani Yazid, Rohana Adnan, Shafida Abdul Hamid, Muhammad Akhyar Farrukh
Turkish Journal of Chemistry
Gold nanoparticles supported on zinc oxide nanoparticles were synthesized at several pH levels via the deposition-precipitation (DP) method. The effects of pH on gold loading, particle size, and particle size distribution on the support were studied at the iso-electric point (IEP) as well as below and above the IEP of ZnO. The addition of the support significantly changed the pH of the solution. The effects of adjusting the pH before and after the addition of the support into the gold chloride solution were also investigated. Gold particles with diameters of less than 5 nm were obtained. The results revealed that …
Synthesis And Super-Swelling Behavior Of A Novel Low Salt-Sensitive Protein-Based Superabsorbent Hydrogel: Collagen-G-Poly(Amps), Mohammad Sadeghi, Hossein Hosseinzadeh
Synthesis And Super-Swelling Behavior Of A Novel Low Salt-Sensitive Protein-Based Superabsorbent Hydrogel: Collagen-G-Poly(Amps), Mohammad Sadeghi, Hossein Hosseinzadeh
Turkish Journal of Chemistry
Superabsorbent polymers are obtained by the graft copolymerization of 2-acrylamido-2-methylpropanesul- fonic acid (AMPS) monomer onto collagen, using ammonium persulfate as a free radical initiator in the presence of methylene bisacrylamide as a crosslinker. Infrared spectroscopy and TGA thermal analysis were carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy (SEM). The effect of reaction variables on swelling capacity was investigated to achieve a hydrogel with improved water absorbency. Under the optimized conditions concluded, maximum capacity of swelling in distilled water was found to be 268 g/g. The swelling …
An Efficient And Green Approach For The Synthesis Of Vinyl Aryl Ethers In The Presence Of Guanidine Hydrochloride, Seyed Mohammad Vahdat, Robabeh Baharfar
An Efficient And Green Approach For The Synthesis Of Vinyl Aryl Ethers In The Presence Of Guanidine Hydrochloride, Seyed Mohammad Vahdat, Robabeh Baharfar
Turkish Journal of Chemistry
A stereoselective procedure for vinyl aryl ether bond formation by direct coupling of dialkyl acetylenedicarboxylates and substituted phenols or naphthols under mild reaction conditions has been developed. Using guanidine hydrochloride as a new catalyst and water-acetone as green solvent, dialkyl acetylenedicarboxylates were reacted with substituted phenols or naphthols in room temperature to produce vinyl aryl ethers in good to excellent yields.
Nile Blue-Hexacyanoferrate Carbon Paste Modified Electrode As An Amperometric Sensor For Determination Of Hydrazine, Reza Sabzi, Elnaz Minaie, Khalil Farhadi, Mirmaqsoud Golzan
Nile Blue-Hexacyanoferrate Carbon Paste Modified Electrode As An Amperometric Sensor For Determination Of Hydrazine, Reza Sabzi, Elnaz Minaie, Khalil Farhadi, Mirmaqsoud Golzan
Turkish Journal of Chemistry
The main problem associated with metal hexacyanoferrates (MHCFs) is their instability at high pH values. We synthesized a new Prussian Blue analogue, Nile-Blue hexacyanoferrate (NBHCF), that remains stable in 0.2 M KOH. A carbon paste (CPE) chemically modified electrode (ME) containing NBHCF was prepared as a stable electrochemical sensor for measuring hydrazine. A detailed characterization of the electrochemical and electrocatalytic behavior of NBHCF was performed using cyclic voltammetric, chronoamperometric, differential pulse voltammetric (DPV) and hydrodynamic amperometric methods. The NBHCF-modified electrode produced reproducible redox peaks and resulted in a linear increase in the oxidation signal of hydrazine with increasing concentration of …
Isolation And Identification Of A New Acetildenafil Analogue Used To Adulterate A Dietary Supplement: Dimethylacetildenafil, Ali̇ Hakan Göker, Maksut Coşkun, Mehmet Alp
Isolation And Identification Of A New Acetildenafil Analogue Used To Adulterate A Dietary Supplement: Dimethylacetildenafil, Ali̇ Hakan Göker, Maksut Coşkun, Mehmet Alp
Turkish Journal of Chemistry
A new sildenafil analogue was found to have been added illegally to a dietary supplement marketed for the enhancement of sexual function. The structure was determined as 5-(2-ethoxy-5- {[4-(3,5-dimethyl)piperazin-1-yl]-acetyl}phenyl)-1,6-dihydro-1-methyl-3- propyl-7H-pyrazolo [4,3-d]pyrimidin-7-one. Owing to the inclusion of a dimethyl group in acetildenafil, the detected compound was called dimethylacetildenafil. The sample was purified with column chromatography. The IR, LC/MS (ESI), and completely assigned NMR data of dimethylacetildenafil are reported for the first time. The structure was compared with that of acetildenafil and the results showed that the ethyl substitution at the 4-position of the piperazine ring had been replaced by a 3,5-dimethyl …
Synthesis Of Some New Biheterocyclic Triazole Derivatives And Evaluation Of Their Antimicrobial Activity, Hakan Bektaş, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Şengül Alpay Karaoğlu
Synthesis Of Some New Biheterocyclic Triazole Derivatives And Evaluation Of Their Antimicrobial Activity, Hakan Bektaş, Ahmet Demi̇rbaş, Nesli̇han Demi̇rbaş, Şengül Alpay Karaoğlu
Turkish Journal of Chemistry
2-{3-(4-Substitutedbenzyl)-4-[2-(1H-indol-3-yl)ethyl]-5-oxo-4,5- dihydro-1H-1,2,4-triazol-1-yl}-N'-(aryl-methylene)acetohydrazides (5a-g), 4-amino-2-{-(4-substitutedbenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol- 1-yl}-N'-(arylmethylene)acetohydrazides (6a,b), and 4-[2-(1H-indol- 3-yl)ethyl]-5-(4-substitutedbenzyl)-2-{5-(phenylamino)-1,3,4-thiadiazol- 2-yl]methyl}-2,4-dihydro-3H-1,2,4-triazol-3-ones (8a,b) were synthesized starting from 4-alkyl-5-(4-substitutedbenzyl)-2,4-dihydro- 3H-1,2,4-triazol-3-ones (2a-c) by several steps and their structures were well characterized by elemental analyses, IR, ^1H-NMR, ^{13}C-NMR, and mass spectral studies. They were also screened for their microbial activities. The obtained antimicrobial activity results revealed that 12 among the 24 compounds tested displayed variable growth inhibition effects on the tested gram-positive and gram-negative bacterial strains. None of the compounds showed antifungal activity against yeast-like fungi.
Chelating Agent Free Solid Phase Extraction (Caf-Spe) Method For Separation And/Or Preconcentration Of Iron(Iii) Ions, Özcan Yalçinkaya, Orhan Murat Kalfa, Ali̇ Rehber Türker
Chelating Agent Free Solid Phase Extraction (Caf-Spe) Method For Separation And/Or Preconcentration Of Iron(Iii) Ions, Özcan Yalçinkaya, Orhan Murat Kalfa, Ali̇ Rehber Türker
Turkish Journal of Chemistry
This paper presents a chelating agent free solid phase extraction (CAF-SPE) method for the separation and/or preconcentration of trace iron(III) ions. This method is based on the sorption of Fe(III) ions without using any chelating agent onto Amberlyst 36 resin. A good relative standard deviation (3%), high recovery (>95%), high enrichment factor (100), and low detection limit (0.32 \mu g L^{-1}) were obtained. The adsorption capacity of resin was 117 mg g^{-1} for iron(III). The method was applied for the determination of iron various in water and commercial tea bag samples. The accuracy of the method was confirmed by …
Comparative Kinetic Studies On The Alkaline Hydrolysis Of Halogen Substituted Isocoumarins, Hafiz Badaruddin Ahmad, Muhammad Aslam Malana, Muhammad Yousaf, Muhammad Rehan, Mazhar Abbas
Comparative Kinetic Studies On The Alkaline Hydrolysis Of Halogen Substituted Isocoumarins, Hafiz Badaruddin Ahmad, Muhammad Aslam Malana, Muhammad Yousaf, Muhammad Rehan, Mazhar Abbas
Turkish Journal of Chemistry
Kinetics of the hydrolysis of 3-(2'-chloro-6'-fluorobenzyl) isocoumarin (1), 3-(4'-fluorophenyl)isocoumarin (3), 3-(2'- fluorophenyl)isocoumarin (5), 3-(2'-chlorophenyl)isocoumarin (7), and 3-(4'-chlorophenyl)isocoumarin (9) were studied spectrophotometrically in the presence of aqueous solution of potassium hydroxide. The rates of hydrolyses for these isocoumarins were compared. The data for isocoumarin (1) were further investigated to probe the reaction mechanism. The dependence of pseudo-first order rate constant k_{obs} on hydroxide ion concentration is fitted by the expression k_{obs} = k_o + k_1[OH] + k_2 [OH]^2, showing the formation of monoanionic and dianionic tetrahedral intermediates during the course of reaction. The magnitude of k_o shows significant participation of solvent …
(E)-3-[(3-(Trifluoromethyl)Phenylimino)Methyl] Benzene-1,2-Diol: X-Ray And Dft Calculated Structures, Başak Koşar, Çi̇ğdem Albayrak, Mustafa Odabaşoğlu, Orhan Büyükgüngör
(E)-3-[(3-(Trifluoromethyl)Phenylimino)Methyl] Benzene-1,2-Diol: X-Ray And Dft Calculated Structures, Başak Koşar, Çi̇ğdem Albayrak, Mustafa Odabaşoğlu, Orhan Büyükgüngör
Turkish Journal of Chemistry
The crystal structure of (E)-3-[(3-(Trifluoromethyl)phenylimino)- methyl]benzene-1,2-diol was determined using X-ray diffraction and the molecular structure was investigated with density functional theory (DFT). The X-ray study showed that the title compound has a strong intramolecular O-H...N hydrogen bond and 3-dimensional crystal networks are primarily determined by O-H...O intermolecular hydrogen bonds and weak van der Waals interactions. The strong O-H...N bond is evidence of the preference for the phenol-imine tautomeric form in the solid state. Optimized molecular geometry was calculated with DFT at the B3LYP/6-31G(d,p) level. The results from both experiment and theoretical calculations for the title compound are compared with each …
Sulfonic Acid-Functionalized Silica: A Remarkably Efficient Heterogeneous Reusable Catalyst For The One-Pot Synthesis Of 1,4-Dihydropyridines, Behzad Mohammadi, Sayyed Mohammad Hosseini Jamkarani, Taghi A. Kamali, Mahmoud Nasrollahzadeh, Ali Mohajeri
Sulfonic Acid-Functionalized Silica: A Remarkably Efficient Heterogeneous Reusable Catalyst For The One-Pot Synthesis Of 1,4-Dihydropyridines, Behzad Mohammadi, Sayyed Mohammad Hosseini Jamkarani, Taghi A. Kamali, Mahmoud Nasrollahzadeh, Ali Mohajeri
Turkish Journal of Chemistry
An efficient one-pot method for the synthesis of 1,4-dihydropyridines from \beta-dicarbonyl compounds, aldehyde, and ammonium acetate is reported using sulfonic acid-functionalized silica at 90 °C under solvent-free conditions with good to excellent yields. The catalyst is easily prepared, stable (up to 300 °C), reusable, and efficiently used under reaction conditions.
Synthesis And Surfactant Properties Of N-Acylation Compounds Derived From Hydrolysis Degradation Products Of N-(\Beta-Cianoethyl)-\Epsilon-Caprolactam, Andreea Bondarev
Synthesis And Surfactant Properties Of N-Acylation Compounds Derived From Hydrolysis Degradation Products Of N-(\Beta-Cianoethyl)-\Epsilon-Caprolactam, Andreea Bondarev
Turkish Journal of Chemistry
N-acyl amino acids can be used as active surface agents in the detergents industry, as well as in the pharmaceutical industry and cosmetics. Properties of these compounds are superior to those of fatty acids soaps and they are not toxic to the environment and have low Kraft points, because of peptide bonds (CO-NH). Acylation at the nitrogen atom can be performed with good yields without catalysts, for strong nucleophilic derivatives. The synthesis of some derivatives of 4-azasebacic acid, which are hydrolysis degradation products from N-(\beta -cianoethyl)-\epsilon -caprolactam, has been described and the N-acylation processes for these compounds are also presented. …
Synthesis And Characterization Of Ba/Mcm-41, Emi̇ne Kaya, Nuray Oktar, Gürkan Karakaş, Kirali̇ Mürtezaoğlu
Synthesis And Characterization Of Ba/Mcm-41, Emi̇ne Kaya, Nuray Oktar, Gürkan Karakaş, Kirali̇ Mürtezaoğlu
Turkish Journal of Chemistry
Mesoporous Ba/MCM-41 type materials (Ba/MCM-41) with high Ba/Si molar ratios between 0.025 and 0.1 were synthesized by direct hydrothermal synthesis. The samples were characterized by XRD, nitrogen adsorption, TGA-DTA, FTIR, SEM-EDS, and TEM techniques. BET surface areas of samples with various Ba loadings were found between 722 and 931 m^2/g with 28 Å average pore size, which is consistent with the pore size of 30 Å for pure MCM-41 samples synthesized by the same procedure. The crystal structures of synthesized MCM-41 and Ba/MCM-41 were confirmed by XRD analysis. Among the investigated Ba/MCM-41 samples, the formation of barium oxide and barium …