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Öğe All-solid-state PVC membrane Ag+-selective electrodes based on diaza-18-crown-6 compounds(Springer Wien, 2004) Isildak, I; Yolcu, M; Isildak, O; Demirel, N; Topal, G; Hosgoren, HTwo diaza-crown ether compounds were synthesized and evaluated as Ag+-selective carriers in polyvinylchloride (PVC) membrane electrodes of solid-state type. The all-solid-state PVC membrane electrode based on N,N-Dibenzyl-dibenzo-diaza-18-crown-6 exhibited a super-Nernstian response (75+/-10 mV per decade) over the concentration range of 1x10(-1) to 7x10(-6) M of Ag+ ion and a detection limit of 3x10(-6) M, at a wide range of pH (pH 4-7). The response time of the electrode was fast (less than similar to10s), and it can be used for three months without any significant deviation in potential. The proposed all-solid-state PVC membrane electrodes revealed high selectivity toward Ag+ ion with respect to alkali, alkaline earth, heavy and transition metal ions. A flow-through cell of all-solid-state PVC membrane Ag+-selective electrode based on N,N-Dibenzyl-dibenzo-diaza-18-crown-6 has also been prepared and applied for flow-injection analysis of Ag+ ion in solution.Öğe Crystal structure of N,N?-bis(dodecyl)diaza-18-crown-6 complexed sodium perchlorate(Springer, 1998) Ozbey, S; Kendi, E; Hosgoren, H; Togrul, MThe crystal structure of a new complex of a diaza-crown ether having two side arms has been determined from X-ray diffraction data. The compound crystallizes in space group P (1) over bar with cell dimensions a = 9.982(1), b = 10.685(1), c = 20.376(2)Angstrom, alpha = 81.09(1), beta = 80.92(1), gamma 88.43(1)(0), Z = 2. The structure has been solved by direct methods and refined to the final R value of 0.053 for 3458 observed reflections and 424 parameters. The diaza-18-crown-6 ligand adopts an approximate D-3d conformation. The Na+ ion is held inside the molecular cavity of this macroring ligand and a ClO4- oxygen coordinates with Na+. The average Na-O (18-crown-6) and Na-N bond lengths are 2.426(4) and 2.786(5)Angstrom, respectively; the Na-O (ClO4-) bond length is 2.472(4)Angstrom. The mean cavity radius is 1.10 Angstrom and the N ... N nonbonding distance is 4.605(6)Angstrom.Öğe Effect of structural modifications of diaza-18-crown-6 on the extractability and selectivity of univalent metal picrates(Elsevier Science Bv, 2001) Ziyadanogullari, B; Topal, G; Erdogan, S; Hamamci, C; Hosgoren, HThe solvent extraction of univalent metal cations with N,N'-dibenzyl-1,4,10,13-tetraoxa-7,16 diaza-2,3,11,12-dibenzocycloocta deca-2,11-diene (L-1), N,N'-didodecyl-1,4,10,13-tetraoxa-7,16-diaza-2,3-benzocylooctadeca-2-ene (L-2) and N,N'-dibenzyl-1,4,10,13-tetraoxa-7,16-diaza-2,3,11,12-dibenzocyclo octadeca-2,11-diene (L-3) with picrate anion into dichloromethane has been studied at 25 degreesC by UV-visible spectroscopy. The extractability and selectivity of univalent metal picrates (Li+, Na+, Ag+, PhCH2NH3+, NH4+) was evaluated as a function of [ligand]/[metal cation]. L-2 showed the highest extractability and selectivity for Lit over the larger studied cations, and also exhibited the highest [Li+]/[NH4+] selectivity as L/M = 1. (C) 2001 Elsevier Science B.V. All rights reserved.Öğe Electrical and optical properties of inorganic complexes C36H76N2O9ClNa and C14H12N2O4TeBr2(Editions Scientifiques Medicales Elsevier, 2001) Aydogdu, Y; Yakuphanoglu, F; Aydogdu, A; Temel, H; Sekerci, M; Hosgoren, HThe electrical properties of some inorganic samples were studied as functions of temperature and the results were analyzed. These samples activation energies were calculated from the electrical conductivity measurements. Also, a detailed study of optical absorption is presented. The optical absorption spectra are measured in the UV+invisible wavelength range 200-1100 nm. The absorption coefficient and value optical energy gaps were determined from the absorption spectra. The complex C36H76N2O9ClNa is characterized by direct optical absorption with an optical edge at 4.49 eV. However, the complex C14H12N2O4TeBr2 is characterized by indirect optical absorption with an optical edge at 1.45 eV, and a nearby direct one at hv = 1.80 eV. (C) 2001 Editions scientifiques et medicales Elsevier SAS. All rights reserved.Öğe The solvent extraction of alkali metal picrates with 4,13-N,N?-dibenzyl-4,13-diaza-18-crown-6(Elsevier Science Bv, 1998) Hamamci, C; Hosgoren, H; Erdogan, SExtraction of alkali metal picrates with N,N'-dibenzyl-18-crown-6 was carried out, with dichloromethane as water-immiscible solvent, as a function [ligand]/[metal cation]. The extractability of metal picrates (Li+, Na+, K+ Rb+, Cs+) was evaluated as a function of [L]/[M+]. The extractability of complex cation-picrate ion pairs decreases in this sequence: Li+ > Rb+ > Cs+ > K+ > Na+. The overall extraction equilibrium constants (K-ex) for complexes of N,N'-dibenzyl-18-crown-6 with alkali metal picrates between dichloromethane and water have been determined at 25 degrees C. The values of the extraction constants (log K-ex) were determined to be 10.05, 6.83, 7.12, 7.83, 6.73 for Li+ Na+, K+, Rb+ and Cs+ compounds, respectively. DB186 shows almost 2-fold extractability against Li+ compared to the other metal picrates, whereas it shows no obvious extractability difference amongst the other metal cations when [L]/[M+] is 0.2-1. However, an increasing extractability is observed for Cs+ when [L]/[M+] [1]. (C) 1998 Elsevier Science B.V. All rights reserved.Öğe Solvent extraction of boron with 1,2-dihydroxy-4-oxadodecane (DHD) in n-amyl alcohol(Marcel Dekker Inc, 1997) Hosgoren, H; Tural, S; Kahraman, F; Togrul, M; Karakaplan, MIn the work presented here, 1,2-dihidroxy-4-oxadodecane (DHD) was synthesized and used for the solvent extraction of boron. DHD was prepared from glycidol and octanol by thermal epoxide ring opening reaction without using acid or base catalyst. The structure of this new extracting reagent was identified according to its spectroscopic data i.e. C-13 NMR, H-1 NMR and elemental analysis results. The fixed 10(-4) M was extracted with different volume standard solution of boron (as borax) of 10 ratios of DHD and n-amyl alcohol (AA) at different equilibrium pH values. The best extraction result was obtained at high pH values with a mixture of equal volumes of DHD and n-amyl alcohol. The different equilibrium pH values were plotted against the extraction yields (%R) and the pH(0.5) value was determined by using this graph. The extraction of boron from aqueous solutions with equal volumes of DHD and various solvents were studied and it was found that petroluem ether, n-amyl alcohol and diisopropyl ether are convinient solvents for boron extraction. Stripping of boron loaded organic phase was achieved with H2SO4 aqueous solutions. The effect of stripping as a function of H2SO4 cocentration was also studied.Öğe Solvent extraction of La3+ with ethylenediamine-N,N?-ditetradecyl-N,N?-diacetic acid (EDDAT) in dichloromethane(Scientific Technical Research Council Turkey, 1998) Yurdakoc, M; Hosgoren, HEthylenediamine-N,N'-ditetradecyl-N,N'-diacetic acid (EDDAT) was synthesized for the solvent extraction of La3+. EDDAT was prepared from ethylenediamine-N,N'-diacetic acid (EDDA) and tetradecyl bromide in a basic n-amylalcohol-ethanol-water solvent system. The structure of this new extracting reagent was identified according to spectroscopic data, i.e. C-13 NMR, H-1 NMR, and elemental analysis results. The solvent extraction of La3+ with EDDAT in dichloromethane was studied as a function of parameters of the aqueous and organic phases. The optimal extraction conditions were determined. The extraction yield increased with a decrease in hydrogen ions in the aqueous phase. Stripping of the La3+ loaded organic phase was achieved with HCl aqueous solution. The effect of stripping as a function of the HCl concentration was also studied.Öğe Synthesis of chiral monoaza-15-crown-5 ethers from a chiral amino alcohol and enantiomeric recognition of potassium and sodium salts of amino acids(Pergamon-Elsevier Science Ltd, 2005) Togrul, M; Askin, M; Hosgoren, HThe enantiomeric recognition of chiral monoaza-crown ethers for amino acids as their sodium and potassium salts has been investigated by UV-vis. The highest discrimination was observed for TrpK (D/L = 6.47). The reversed enantioselectivity of chiral monoaza-crown ether ll was observed for TrpK. (c) 2005 Elsevier Ltd. All rights reserved.Öğe Synthesis of new lariat cyclicdiamides and their metal complexes(Kluwer Academic Publ, 1996) Cakir, U; Karakaplan, M; Temel, H; Hosgoren, H; Erk, CThree new lariat dilactam host molecules were prepared by the reaction of triethyleneglycol dicarboxylic acid dichloride with N, N'-disubstituted-4, 7-dioxa-1, 10-diazadecane precursors. The amide nitrogen pivot of such compounds are substituted with the benzyl, octyl and dodecyl groups. The complexing ability of these dilactams is displayed with a series of metal complexes of Na+, K+, Ca2+, Sr2+, Pb2+ and Ag+ ions. The structures determined are consistent with the data of H-1-NMR, C-13-NMR, IR spectra and elemental analyses.Öğe Synthesis of two-armed macrocycles via N,N'-disubstituted omega,omega'-diaminoether precursors(Inst Organic Chem and Biochem, 1996) Hosgoren, H; Karakaplan, M; Togrul, MN,N'-Dialkyldiazacrowns and their precursors, bis(alkylamino) derivatives of tri- and tetraethylene glycols, are synthesized and characterized.
