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Triterpene Saponins From Nigella Sativa L., Mustafa Kemal Taşkin, Özgen Alankuş Çalişkan, Hüseyi̇n Anil, Hassan Abou-Gazar, Ikhlas A. Khan, Erdal Bedi̇r
Triterpene Saponins From Nigella Sativa L., Mustafa Kemal Taşkin, Özgen Alankuş Çalişkan, Hüseyi̇n Anil, Hassan Abou-Gazar, Ikhlas A. Khan, Erdal Bedi̇r
Turkish Journal of Chemistry
Three known triterpene glycosides were isolated from the MeOH extract of dried and powdered seeds of Nigella sativa. The structures of the compounds were established as 3-O-[\beta-D-xylopyranosyl- (1 \to 3)-\alpha-L-rhamnopyranosyl-(1 \to 2)-\alpha -L-arabinopyranosyl]- 28-O-[\alpha-L-rhamnopyranosyl-(1 \to 4)-\beta-D-glucopyranosyl-(1 \to 6)- \beta-D-glucopyranosyl]-hederagenin (1), 3-O-[\alpha -L-rhamnopyranosyl- (1 \to 2)-\alpha-L-arabinopyranosyl]-28-O-[\alpha -L-rhamnopyranosyl-(1 \to 4)- \beta-D-glucopyranosyl-(1\to 6)-\beta-D-glucopyranosyl]-hederagenin (2), and 3-O-[\beta-D-xylopyranosyl- (1\to 3)-\alpha-L-rhamnopyranosyl-(1\to 2)-\alpha- L-arabinopyranosyl]-hederagenin (3) by means of chemical and spectral methods. Compound 2 was isolated for the first time from the genus Nigella.
Manganese(Iii) Acetate Mediated Free Radical Cyclization Of 1,3-Dicarbonyl Compounds With Sterically Hindered Olefins, Mehmet Yilmaz, Emre Bi̇çer, A. Tarik Pekel
Manganese(Iii) Acetate Mediated Free Radical Cyclization Of 1,3-Dicarbonyl Compounds With Sterically Hindered Olefins, Mehmet Yilmaz, Emre Bi̇çer, A. Tarik Pekel
Turkish Journal of Chemistry
The manganese(III) acetate mediated radical cyclization of dimedone 1a, 2,4-pentanedione 1b, ethyl acetoacetate 1c, 1,3-cyclohexanedione 1d and 5-phenyl-1,3-cyclohexanedione 1e with 1,1-diphenyl-1-butene 2a afforded 4,5-dihydrofurans (3c, 3e) and tetrahydrobenzofurans (3a, 3g, 3h) in good yields (55% - 77%). Additionally, the reactions of trifluoromethyl-group containing 1,3-dicarbonyls, 4,4,4-trifluoro-1-phenylbutane-1,3-dione 1f and 4,4,4-trifluoro-1-thien-2ylbutane-1,3-dione 1g with 2a 3-trifluoroacetyl-4,5-dihydrofurans gave in 74% and 78% yields, respectively. Treatment of 1a, 1b and 1c with 1,2-diphenyl-1-pentene 2a resulted in the formation of tetrahydrobenzofuran 3b and 4,5-dihydrofurans 3d and 3f in lower yields.
Interpretation Of Sorption Kinetics For Mixtures Of Reactive Dyes On Wool, Eli̇f Şahi̇n
Interpretation Of Sorption Kinetics For Mixtures Of Reactive Dyes On Wool, Eli̇f Şahi̇n
Turkish Journal of Chemistry
The equilibrium sorption isotherms of 3 reactive dyes (C. I. Reactive Yellow 84, C. I. Reactive Red 141, C. I. Reactive Blue 160) and their binary mixtures adsorbed on prewetted wool fiber were investigated. The kinetic studies were carried out at pH \le 7 and 80 °C in dye solutions containing 20 g/L NaCl. It was reported that binary mixtures of these reactive dyes have lower sorption values than the dyes alone, at the same dye concentration, pH and temperature. The isotherms obtained are Langmuir type. The rate parameters of adsorption kinetics decrease with increasing dye concentration.
Spectrophotometric Study Of The Interaction Between Aza-15-Crown-5 And Some \Pi-Acceptors In Chloroform Solution, H. R. Pouretedal, A. Semnani, Mohammad Hossein Keshavarz, A. Firooz
Spectrophotometric Study Of The Interaction Between Aza-15-Crown-5 And Some \Pi-Acceptors In Chloroform Solution, H. R. Pouretedal, A. Semnani, Mohammad Hossein Keshavarz, A. Firooz
Turkish Journal of Chemistry
A spectrophotometric study concerning the interaction between A15C5 as n-donor and TCNE, DDQ, TCNQ and bromanil as \pi -acceptor was been performed in chloroform at 25 °C. The results of TCNE indicate the formation of a 1:1 charge-transfer complex through a nonequilibrium reaction. In the case of DDQ, the formation of 1:2 (A15C5/DDQ) and 1:1 charge-transfer complexes through equilibrium and nonequilibrium reactions is confirmed. The formation constant of the equilibrium step was evaluated from the computer fitting of the absorbance-mole ratio data as logK_f = 5.14 \pm 0.09. The [A15C5^+ (DDQ)_2^- ] and [A15C5^+DDQ^- ] are suggested as the possible …
Determination Of Trace Copper By Faas After Solid Phase Extraction And Preconcentration Onto Amberlite Xad-2 Loaded With Nitroso-R Salt, Mohammad Ali Taher, Sayed Ziae Mohammadi Mobarakeh, Ali Reza Mohadesi
Determination Of Trace Copper By Faas After Solid Phase Extraction And Preconcentration Onto Amberlite Xad-2 Loaded With Nitroso-R Salt, Mohammad Ali Taher, Sayed Ziae Mohammadi Mobarakeh, Ali Reza Mohadesi
Turkish Journal of Chemistry
A procedure for the separation and preconcentration of trace amounts of copper is proposed. It is based on the adsorption of copper(II) ions solution onto a column of Amberlite XAD-2 resin loaded with disodium 1-nitroso-2-naphthol-3, 6-disulfonate (nitroso-R salt). Copper is quantitatively retained on the column in the pH range 5.5-7.8 at a flow rate of 2 mL min^{-1}. The copper complex eluted with 5 mL of dimethylformamide (DMF) and copper was measured by flame atomic absorption spectrometry (FAAS) at 324.8 nm. In this case, 0.10 \mu g of copper can be concentrated in the column from 800 mL of aqueous …
Flavonoids From The Leaves Of Impatiens Bicolor, Aurangzeb Hasan, Muhammad Nawaz Tahir
Flavonoids From The Leaves Of Impatiens Bicolor, Aurangzeb Hasan, Muhammad Nawaz Tahir
Turkish Journal of Chemistry
Three new flavanone glycosides, naringenin 4'-O-\beta-D-glucuronopyranoside, naringenin 4'-O-\alpha-L rham\-nopyranoside and naringenin 4'-O-\beta-D-xylopyranoside, were characterized from the leaves of Impatiens bicolor, together with 6 known glycosides: naringenin 4'-O-\beta-D-glucopyranoside, kaempferol 7-O-\beta-D-glucuronopyranoside, quercetin 3-O-\beta-D-glucopyranoside, kaempferol 5-O-\beta-D-xylopyranoside, kaempferol 3-O-\beta-D-galactopyranoside and kaempferol 7-O-\beta-D-xylopyranoside. The structures were determined by means of co-chromatography, UV, HPLC, EI-MS, FAB-MS and ^1H NMR.
Voltammetric, Uv Absorption And Viscometric Studies Of The Interaction Of Norepinephrine With Dna, Mehmet Aslanoğlu, Necla Öge
Voltammetric, Uv Absorption And Viscometric Studies Of The Interaction Of Norepinephrine With Dna, Mehmet Aslanoğlu, Necla Öge
Turkish Journal of Chemistry
Voltammetric, UV-vis spectroscopic and viscometric methods were used to investigate the interaction between norepinephrine and DNA. The results of square wave voltammetric and UV-absorption measurements have shown that norepinephrine was bound to DNA. Besides the electrostatic interaction between DNA and norepinephrine, hydrogen bonds and intercalation may also exist. Viscosity measurements also suggest that NE is bound to DNA via an electrostatic mode of interaction at lower norepinephrine concentrations. However, at higher concentrations of norpinephrine, the increase in the relative viscosity of DNA indicated that the intercalation is also involved in the binding. The binding constant and the binding site size …
Organotin(Iv) Derivatives Of N-Maleoylamino Acids: Their Synthesis And Structural Elucidation, Moazzam H. Bhatti, Saqib Ali, Farhat Huma, Saira Shahzadi
Organotin(Iv) Derivatives Of N-Maleoylamino Acids: Their Synthesis And Structural Elucidation, Moazzam H. Bhatti, Saqib Ali, Farhat Huma, Saira Shahzadi
Turkish Journal of Chemistry
Organotin carboxylates of general formula R_3SnL (1), (2), (4) and (6), R_2SnL_2 (5) and {[(R_2SnL)_2O]_2} (3), where L = N-maleoylglycinate, N-maleoyl-\beta-alaninate and N-maleoylmethioninate, were prepared. The synthesis of these compounds was achieved by either reaction of organotin halides, R_3SnCl, with triethylammonium salt of N-maleoylamino acids or/and organotin oxides, (R_3Sn)_2O and R_2SnO, with maleamic acid in the presence of triethyl amine. These compounds were characterized by FT-IR, multinuclear NMR (^1H, ^{13}C and ^{119}Sn), mass and ^{119m}Sn Mössbauer spectroscopy. The geometry around the tin atom is compared both in solution and in solid state. Different literature methods were employed to calculate the …
Development Of Gold Porous Plate Electrode And Examination Of Its Performance For Iodine Determination, Ülkü Anik Kirgöz, Hüseyi̇n Tural
Development Of Gold Porous Plate Electrode And Examination Of Its Performance For Iodine Determination, Ülkü Anik Kirgöz, Hüseyi̇n Tural
Turkish Journal of Chemistry
A novel procedure for the construction of a home-made gold porous plate electrode is described. A plate of silver and gold alloy was treated with nitric acid or alternatively by anodic oxidation to remove the silver component, leaving a porous surface having active sites for adsorption. The performance of the electrode developed was tested using iodine solution as analyte material. The parameters related to the working conditions were optimized before the examination of analytical characteristics. Under the optimal conditions, the voltammetric results show that the gold porous plate electrode offers the detection limit of 2.18 x 10^{-5} M and reproducibility …
Analysis Of The Essential Oil Composition Of Sideritis Albiflora Using Direct Thermal Desorption And Headspace Gc-Ms Techniques, Gülaçti Topçu, Asli Barla, Ahmet C. Gören, Gökhan Bi̇lsel, Mi̇ne Bi̇lsel, Gülendam Tümen
Analysis Of The Essential Oil Composition Of Sideritis Albiflora Using Direct Thermal Desorption And Headspace Gc-Ms Techniques, Gülaçti Topçu, Asli Barla, Ahmet C. Gören, Gökhan Bi̇lsel, Mi̇ne Bi̇lsel, Gülendam Tümen
Turkish Journal of Chemistry
The main constituents of Sideritis albiflora were found to be trans-caryophyllene, \alpha-pinene, \beta-pinene, \gamma-cadinene, pulegone, and caryophyllene oxide by both thermal desorption GC/MS and headspace GC/MS techniques.
Excellent And Convenient Procedures For Reduction Of Benzene And Its Derivatives, Ali̇ye Altundaş, Abdullah Menzek, Demet Demi̇rci̇ Gülteki̇n, Melek Karakaya
Excellent And Convenient Procedures For Reduction Of Benzene And Its Derivatives, Ali̇ye Altundaş, Abdullah Menzek, Demet Demi̇rci̇ Gülteki̇n, Melek Karakaya
Turkish Journal of Chemistry
Reductions of benzene, toluene, ortho-xylene, cumene, anisole and benzoic acid to corresponding nonconjugated dienes were realized at room temperature by gas NH_3 and Li. The reduced products were easily isolated because THF and dioxane were dissolved in the water. The yields and conversions of the reactions were 70-89% and 80-100%, respectively.
The Electroanalytical Determination Of Sodium Borohydride Using A Gold Electrode, Hüseyi̇n Çeli̇kkan, Hasan Aydin, M. Levent Aksu
The Electroanalytical Determination Of Sodium Borohydride Using A Gold Electrode, Hüseyi̇n Çeli̇kkan, Hasan Aydin, M. Levent Aksu
Turkish Journal of Chemistry
It was shown that square wave voltammetry, a technique with a much lower detection limit, could be successfully used in the detection of borohydride formed in alkaline medium. A Au electrode was found to be very suitable for this purpose. The detection limit was 3 x 10^{-5} M.
A New Approach To The Ring Opening Reactions Of 2,7,7-Trimethyl-3,3-Dibromotricyclo[4.1.1.0^{2,4}]Octane, Zeki̇ Şenol, Ömer Zai̇m, Meti̇n Balci
A New Approach To The Ring Opening Reactions Of 2,7,7-Trimethyl-3,3-Dibromotricyclo[4.1.1.0^{2,4}]Octane, Zeki̇ Şenol, Ömer Zai̇m, Meti̇n Balci
Turkish Journal of Chemistry
The reaction of \alpha-pinene and dibromocarbene produced a fairly unstable product, 2,7,7-trimethyl-3,3-dibromotricyclo[4.1.1.0^{2,4}]octane, from which 3-bromo-7,7-dimethyl-2-methylenebicyclo[4,1,1]oct-3-ene and 3-bromo-2,7,7-trimethylbicyclo [4,1,1]octa-2,4-diene were obtained in chloroform at room temperature and in various other media and conditions. Two new compounds, 3-bromo-2,7,7-trimethylbicyclo [4.1.1]oct-3-en-2-ol and 2-(4-bromo-5-methylcyclohepta-3,5-dien-1-yl) propan-2-ol, were observed in aqueous acetone in addition to the previous two. The stability and formation mechanism of the formed products are discussed
An Unusual Pentacyclic Dinitrogenous Alkaloid From Galanthus Gracilis, Nehi̇r Ünver, Gülen İrem Kaya
An Unusual Pentacyclic Dinitrogenous Alkaloid From Galanthus Gracilis, Nehi̇r Ünver, Gülen İrem Kaya
Turkish Journal of Chemistry
A minor alkaloid, namely gracilamine, was isolated from Galanthus gracilis. This was the first example of a pentacyclic dinitrogenous alkaloid isolated from a member of Amaryllidaceae. The structure of this alkaloid was elucidated by means of comprehensive spectroscopic methods (1D and 2D NMR, MS, UV, IR).
Polyphenolic Compounds And Antimicrobial Activity Of Quercus Aucheri Leaves, Mahmut Koray Sakar, Di̇dem Şöhretoğlu, Meral Özalp, Meli̇ke Eki̇zoğlu, Sonia Piacente, Cosimo Pizza
Polyphenolic Compounds And Antimicrobial Activity Of Quercus Aucheri Leaves, Mahmut Koray Sakar, Di̇dem Şöhretoğlu, Meral Özalp, Meli̇ke Eki̇zoğlu, Sonia Piacente, Cosimo Pizza
Turkish Journal of Chemistry
Chromatographic studies (CC, VLC, MPLC, and PTLC) on ethyl acetate extract from the leaves of Quercus aucheri yielded 2 flavonoids (quercetin 3-O-\alpha-L-arabinopyranoside (1), quercetin 3-O-\beta-D-galactopyranoside (2)) and 2 tannin precursors and a procyanidin [(isolated as peracetates of (+)-catechin (3a), (+)-gallocatechin (4a) and epicatechin-(4\beta \to 8)-catechin (5a))]. The structures of the compounds were elucidated by UV, 1D-NMR (^1H, ^{13}C, TOCSY) and 2D-NMR (COSY, HSQC, HMBC) techniques. Different extracts (80% MeOH, EtOAc, n-BuOH and H_2O) from the leaves of Q. aucheri were investigated for their antimicrobial activity against 2 Gram-positive and 2 Gram-negative bacteria and 3 yeast-like fungi by a broth microdilution …
The Crystal And Molecular Structure Of New Hydrogen Dinitrate Of Nitrato(2,2',2''-Terpyridyl)Platinum(Ii) Ion, [Pt(Terpy)Ono_2][H(Ono_2)_2], Abdurrahman Şengül
The Crystal And Molecular Structure Of New Hydrogen Dinitrate Of Nitrato(2,2',2''-Terpyridyl)Platinum(Ii) Ion, [Pt(Terpy)Ono_2][H(Ono_2)_2], Abdurrahman Şengül
Turkish Journal of Chemistry
The title compound, C_{15}H_{12}N_6O_9Pt, consists of [Pt(terpy)ONO_2]^+ cation and [H(ONO_2)_2]^- anion, in which 2 nitrate groups are linked by a strong hydrogen bond [O \cdots O 2449(1) Å]. In the cation, the terpyridine is coordinated to Pt as a tridentate ligand and the fourth position is occupied by the nitrate ion's oxygen. The coordination around Pt is square-planar. The coordinated nitrate moiety adopts a distorted trigonal-planar configuration. It belongs to the space group P \bar{1} with a = 8.605(2), b = 10.220(3) Å, c = 10.517(2) Å and \alpha = 89.51(1), \beta = 82.78(2), \gamma = 76.90(2)°.
Catalytic Oxidation Properties And Characterization Of Lasrco_{0.9}B'_{0.1}O_4 (B'= Mn, Fe, Ni, Cu) Mixed Oxides, Laitao Luo, Guangxin Shao, Zhanhui Duan
Catalytic Oxidation Properties And Characterization Of Lasrco_{0.9}B'_{0.1}O_4 (B'= Mn, Fe, Ni, Cu) Mixed Oxides, Laitao Luo, Guangxin Shao, Zhanhui Duan
Turkish Journal of Chemistry
Using a polyacrylamide gel method, a series of LaSrCo_{0.9}B'_{0.1}O_4 (B'= Mn, Fe, Ni, Cu) mixed oxides were prepared and their catalytic activity was studied with CO and C_3H_8 oxidations as a testing reaction. The results show that the specific effects of B' ions on CO and C_3H_8 oxidations depend on their category. In comparison to LaSrCoO_4 catalyst, the activity of LaSrCo_{0.9}Ni_{0.1}O_4 catalyst for CO and C_3H_8 oxidations is higher, while only lower activity is obtained for Mn, Fe or Cu-doped catalysts. The information derived from TPD, XRD and iodometry experiments shows that the increase in oxidation activity of LaSrCo_{0.9}Ni_{0.1}O_4 catalyst …
Spectroscopic And Luminescence Properties Of An Isonicotinic Acid, Nurdoğan Can, Ahmet Ataç, Fehmi̇ Bardak, Şebnem Esen Sözerli̇ Can
Spectroscopic And Luminescence Properties Of An Isonicotinic Acid, Nurdoğan Can, Ahmet Ataç, Fehmi̇ Bardak, Şebnem Esen Sözerli̇ Can
Turkish Journal of Chemistry
An isonicotinic acid N-oxide Zn(II) compound was characterized on the basis of elemental analysis. FTIR spectra of the compound and free isonicotinic acid N-oxide (INO) were recorded in the range 4000--400 cm^{-1}. Cathodoluminescence (CL) spectra from the Zn(INO)_2 complex were recorded. The luminescence data were interpreted in terms of the emission band at 470 nm. The green luminescence (\sim 470 nm) arises from Zn^{2+} transition ^4T_1 (^4G) \to ^6A_1 (^6S). It shows a weak vibronic structure, and short lifetimes less than 150 \mu s. The lifetime and intensity of the signal are temperature dependent, and the parameters are reported for …
Investigation Of Electron Transfer Reaction Between Diphenylbenzidine And Ascorbic Acid, Iftikhar Imam Naqvi, Abida Perveen
Investigation Of Electron Transfer Reaction Between Diphenylbenzidine And Ascorbic Acid, Iftikhar Imam Naqvi, Abida Perveen
Turkish Journal of Chemistry
The kinetics of the reduction of diphenylbenzidine by ascorbic acid were investigated in the pH range 3.5 to 5.0. Diphenylbenzidine was prepared by the oxidation of diphenylamine with cerium(IV) sulfate tetra hydrate. The order of the reaction with respect to each of the reactants, i.e ascorbic acid (ASC), diphenylbenzidine (DPB) and H^+ ,was found to be first. The following rate law is recommended: Rate = {k_1 [C_{12}H_{10}N_2C_{12}H_{10}] + k_2K [C_{12}H_{10}N_2C_{12}H_{10}][H^+]}[C_6H_8O_6] where k_1 and k_2 have the values of 2.0 \times 10^4 dm^3mol^{-1} s^{-1} and 6.58 \times 10^3 dm^3.mol^{-1}.s^{-1} , respectively. K is the protonation constant of DPB, having a value …
A New Approach Towards (\Pm)-4-Ipomeanol And Its 2-Furyl Regioisomer, Jurgen Krauss, Franz Bracher, Doris Unterreitmeier
A New Approach Towards (\Pm)-4-Ipomeanol And Its 2-Furyl Regioisomer, Jurgen Krauss, Franz Bracher, Doris Unterreitmeier
Turkish Journal of Chemistry
The cytotoxic furan derivative (\pm)-4-ipomeanol (1) and its regioisomer (8) were prepared in a new and efficient way starting from commercially available furan derivatives. In both cases the key step was a regioselective solvolysis of the terminal double bond with trifluoroacetic anhydride and boron trifluoride. The resulting compounds were tested in an agar diffusion assay against several bacteria and fungi, but did not show significant activity.
Synthesis, Characterization And Genotoxicity Of Platinum(Ii)Complexes With Subtituted Benzimidazole Ligands, Özteki̇n Algül, Berri̇n Özçeli̇k, Ufuk Abbasoğlu, Fatma Gümüş
Synthesis, Characterization And Genotoxicity Of Platinum(Ii)Complexes With Subtituted Benzimidazole Ligands, Özteki̇n Algül, Berri̇n Özçeli̇k, Ufuk Abbasoğlu, Fatma Gümüş
Turkish Journal of Chemistry
Five Pt(II) complexes with the ligands 2-ethyl-/ or-benzyl-/ or-phenoxymethyl- and 1-methyl-2-hydroxymethyl- and 1-methyl-2-phenyl- benzimidazoles were synthesized and characterized by elemental analysis, and IR and ^1H-NMR spectra and evaluated for their in vitro genotoxic activities by Rec-Assay test. Based on the data obtained in this study, the Pt(II) complexes tested might be taken into consideration as promising antitumor compounds.
Heterogeneous Electron Transfer Rate Constants Of Viologen At A Platinum Disk Electrode, Naheed Kaukab Bhatti, M. Sadiq Subhani, Ather Yaseen Khan, Rumana Qureshi, Abdur Rahman
Heterogeneous Electron Transfer Rate Constants Of Viologen At A Platinum Disk Electrode, Naheed Kaukab Bhatti, M. Sadiq Subhani, Ather Yaseen Khan, Rumana Qureshi, Abdur Rahman
Turkish Journal of Chemistry
The transfer of electrons to the dications of viologens including methyl viologen, diquat, benzyl viologen and n-butyl viologen was studied at the surface of a platinum disk electrode. The rate constants for the processes were determined and the effects of solvent, temperature and working electrode studied. The studies showed that the rate constants increase with temperature and the effect of solvent on the heterogeneous electron transfer rate constant is related to the polarity, dielectric constant and viscosity of the solvent and on the electrode material. Theoretical rate constants were calculated by considering the effects of barrier crossing probability and nuclear-frequency …
Extraction-Spectrophotometric Determination Of Trace Amounts Of Barium And Strontium By 18-Crown-6 And Rose Bengal Using Partial Least Squares, Jahan B. Ghasemi, Alireza Nikrahi, Ali Niazi
Extraction-Spectrophotometric Determination Of Trace Amounts Of Barium And Strontium By 18-Crown-6 And Rose Bengal Using Partial Least Squares, Jahan B. Ghasemi, Alireza Nikrahi, Ali Niazi
Turkish Journal of Chemistry
Partial least squares modeling is a powerful multivariate statistical tool applied to extraction-spectrophotometric simultaneous determination of mixtures of barium and strontium. The method is based on the formation of the ternary complexes with 18C6 and rose bengal with barium and strontium. The 18C6-Ba-RB and 18C6-Sr-RB ternary complexes are quantitatively extracted into dichloromethane and the resolution of the mixtures is accomplished by partial least squares (PLS). In this study, the calibration model is based on absorption spectra in the 500-600 nm range for 25 different mixtures of barium and strontium. Calibration matrice's ranges were 0.05-5.50 and 0.03-4.50 \mu g mL^{-1} and …
Reactions Of Alkenes With Sodium Perborate And Sodium Chloride, Erdal Şenocak, Yavuz Taşkesengi̇l, Ferhan Tümer, Cavi̇t Kazaz
Reactions Of Alkenes With Sodium Perborate And Sodium Chloride, Erdal Şenocak, Yavuz Taşkesengi̇l, Ferhan Tümer, Cavi̇t Kazaz
Turkish Journal of Chemistry
Sodium perborate oxidatively chlorinates a variety of alkenes with sodium chloride to form the corresponding chloro derivatives under mild conditions.
Construction And Characterization Of Indium Liquid Ion Selective Electrodes Based On Crown Ethers In A Pvc Matrix Membrane, Najwa I. Abdulla, Abdul-Muhsin Al-Haideri, Moen I. Al-Joboury, Nabil S. Nassory
Construction And Characterization Of Indium Liquid Ion Selective Electrodes Based On Crown Ethers In A Pvc Matrix Membrane, Najwa I. Abdulla, Abdul-Muhsin Al-Haideri, Moen I. Al-Joboury, Nabil S. Nassory
Turkish Journal of Chemistry
Several indium ion selective electrodes were constructed based on 15-crown-5 (15C5), dicyclohexano-18-crown-6 (DCH18C6) and dibenzo-24-crown-8 (DB24C8) as sensors and di-octyl phenyl phosphonate (DOPP), di-butyl phthalate (DBPH), tri-butyl phosphate (DBP), tri-n-amyl phosphate (TAP) and bis (2-ethyl hexyl) phosphate (BEHP) as plasticizers in a PVC matrix membrane. Electrode parameters, pH effect and interferences were also studied. The indium electrode based on 15C5 using DOPP as a plasticizer gave the best response for low levels of In^{3+} ions. The linear range for this electrode ranged from 3.8 x 10^{-5} to 5.0 x 10^{-2} M (with correlation coefficient r = 0.9997), the slope was …
Characterization Of Tio_2 Synthesized In Alcohol By A Sol-Gel Process: The Effects Of Annealing Temperature And Acid Catalyst, Funda Sayilkan, Meltem Asi̇ltürk, Hi̇kmet Sayilkan, Yunus Önal, Murat Akarsu, Ertuğrul Arpaç
Characterization Of Tio_2 Synthesized In Alcohol By A Sol-Gel Process: The Effects Of Annealing Temperature And Acid Catalyst, Funda Sayilkan, Meltem Asi̇ltürk, Hi̇kmet Sayilkan, Yunus Önal, Murat Akarsu, Ertuğrul Arpaç
Turkish Journal of Chemistry
The effects of annealing temperature and hydrolysis catalyst on the crystalline form and crystallite size of TiO_2 prepared by a sol-gel process were investigated. Three types of TiO_2 were synthesized by hydrolysis of titanium(IV)-iso-propoxide with water in n-propanol without catalyst (Type-A) and with HCl as catalyst, where the H^+ /Ti^{4+} mol ratio was 0.54 for Type-B and 0.2 for Type-C. Hydrolysis products were thermally treated at 100, 200, 300, 400 and 500 °C for 1 h after drying at room temperature. Characterization of the particles was carried out using XRD, BET, TG/DTA and SEM analysis. The pore size distributions were …
Synthesis And Reactivity Of Tetrahydroimidazo [1,5-B][1,2,4]Oxadiazol- 2(1h)-Thiones, Necdet Coşkun, Fatma Ti̇rli̇ Tat
Synthesis And Reactivity Of Tetrahydroimidazo [1,5-B][1,2,4]Oxadiazol- 2(1h)-Thiones, Necdet Coşkun, Fatma Ti̇rli̇ Tat
Turkish Journal of Chemistry
1,3-Dipolar cycloaddition of imidazoline 3-oxides 1 with methylisothiocyanate proceeds regio- and diastereoselectively to give tetrahydroimidazo[1,5-b][1,2,4]oxadiazol-2(1H)-thiones 3 in high yields. The cis configuration of the adducts was proved by our double cis elimination test as well as by NOESY experiments. Adducts 3a-c undergo ring opening at reflux in acetonitrile to give imidazoles while 3d-e undergo retro dipolar cycloaddition to give the starting nitrones 1d-e. The imidazooxadiazol-2-thiones 3a-e were treated with concentrated HCl in ethanol at 50 °C to give the corresponding 4H-[1,2,4]oxadiazole-5-thione only in cases in which the substituent at C-6 is an aryl.
Kinetics And Mechanism Of Oxidation Of N--Propanolamine By Dihydroxydiperiodatonickelate(Iv) In Alkaline Medium, Jin-Huan Shan, Jing Qian, Ming-Zhu Gao, Shi-Gang Shen, Han-Wen Sun
Kinetics And Mechanism Of Oxidation Of N--Propanolamine By Dihydroxydiperiodatonickelate(Iv) In Alkaline Medium, Jin-Huan Shan, Jing Qian, Ming-Zhu Gao, Shi-Gang Shen, Han-Wen Sun
Turkish Journal of Chemistry
The kinetics of oxidation of n--Propanolamine (n-PA) by dihydroxy diperiodato-nickelate(IV) (DPN) in alkaline medium was studied with spectrophotometry in a temperature range of 293.2-308.2 K. The reaction was found to be pseudo first-order with respect to DPN and fractional order to n-PA. The rate conatant k_{obs}, rose with an increase in the concentration of OH^{-} and a decrease in the concentration of IO_{4}^{-}. Added salts did not affect the rate and no free radical was detected. From the evaluation of linear data, a reaction mechanism is proposed which involves a pre-equilibrium of an adduct formation between n-PA and dihydroxymonoperiodatonickelate(IV) (MPN), …
Synthesis, Spectral Characterization And Biological Applications Of Tri- And Diorganotin(Iv) Derivatives Of 2-[N-(2,6-Dichloro-3-Methylphenyl)Amino]Benzoic Acid, Sohail Mahmood, Saqib Ali, Moazzam Hussain Bhatti, Mohammad Mazhar, Khadija Shahid, Khalid Mohammed Khan, Ghulam Mustafa Maharvi
Synthesis, Spectral Characterization And Biological Applications Of Tri- And Diorganotin(Iv) Derivatives Of 2-[N-(2,6-Dichloro-3-Methylphenyl)Amino]Benzoic Acid, Sohail Mahmood, Saqib Ali, Moazzam Hussain Bhatti, Mohammad Mazhar, Khadija Shahid, Khalid Mohammed Khan, Ghulam Mustafa Maharvi
Turkish Journal of Chemistry
A series of tri- and diorganotin(IV) compounds with the general formulae R_{3}SnL and R_{2}SnL_{2} (where R = Me, n-Bu, Ph and L = 2-[N-(2,6-dichloro-3-methylphenyl)-amino]benzoate) were synthesized. These compounds were characterized by different instrumental methods such as infrared, multinuclear NMR (^{1}H, ^{13}C, ^{119}Sn) and mass spectrometry. The spectroscopic investigation illustrates that the carboxylate group acts as a bidentate in solid state and as a monodentate in solution. Biological screening tests reveal that the investigated compounds have potential as antibacterial agents.