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Öğe Crystal structure of an inclusion complex between chiral monoaza-15-crown-5 and S(-)-1-phenyl-ethyl ammonium percholorate(R Oldenbourg Verlag, 2003) Özbey, S; Kaynak, FB; Togrul, M; Demirel, N; Hosgören, HA new type of inclusion complex, S(-)-1 phenyl ethyl ammonium percholorate complex of R-(-)-2-ethyl-N-benzyl-4,7,10,13-tetraoxa-1-azacyclopentadecane, has been prepared and studied by NMR, IR and single crystal X-ray diffraction techniques. The compound crystallizes in space group P2(1) with cell dimensions a = 10.0000(8), b - 12.281(2), c = 12.331(1)Angstrom, beta = 102.052(7), Z = 2. The host-guest complex is held together by a strong system of hydrogen bonds between the two protons of the ammonium ion as well as the nitrogen and four oxygen atoms of the crown ether The C-O and C-C distances of the 15-membered ring average 1.418 and 1.501 Angstrom while the O-C-C and C-O-C angles average 110.2 and 113.3degrees. The average N-C distance is 1.476 Angstrom.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 The enantiomeric recognition of chiral organic ammonium salts by chiral monoaza-15-crown-5 ether derivatives(Pergamon-Elsevier Science Ltd, 2004) Turgut, Y; Sahin, E; Togrul, M; Hosgören, HNovel chiral monoaza-15-crown-5 ether derivatives 1 and 2 were prepared frorn L-phenylalaninol and L-leucinol, respectively. The effect of the substituent at the stereogenic center on chiral recognition and enantioselectivity were investigated. Binding constant (K), free-energy changes (-DeltaG(0)), enthalpy change (DeltaH), and entropy change (DeltaS) values were determined with enantiomers of organic ammonium salts by a titration UV-vis method in CHCl3. (C) 2004 Elsevier Ltd. All rights reserved.Öğe Photomodulated molecular recognition of the guanidinium cation(Royal Soc Chemistry, 2004) Hunter, CA; Togrul, M; Tomas, SAzobenzene moieties were incorporated into a synthetic receptor allowing its affinity for the guanidinium cation to be modulated ten-fold by photoirradiation and/or heating.Öğe Saligenin derivative borocryptands(Science Reviews Ltd, 2003) Togrul, M; Sünkür, M; Kaynak, FB; Hosgören, H; Özbey, SA new lithium receptor based on the combination of the [11] macrocyclic core and two 4-tert-butyl saligenin units was designed and prepared.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 Synthesis of chiral crown ethers and complexation with chiral protonated amine compounds(Springer, 2004) Togrul, M; Demirel, N; Kaynak, FB; Özbey, S; Hosgören, HThe X-ray crystal structure of IX, perchlorate salt of R-(-)-2-ethyl-N-benzyl-4,7,19,13-tetraoxa-8,9-benzo-1-azacyclopentadec-8-ene has been determined. In the molecule, the protonated nitrogen atom participates in two N-(HO)-O-... hydrogen bonds. The unusually high proton affinity of aza crown ether leads to the formation of diastreomer instead of complex formation with chiral R-(+)-1-phenyl ethyl ammonium perchlorate and S-(-)-1-phenyl ethyl ammonium perchlorate. The complex ability of host ethers was evaluated in terms of structural modification.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 R-(-)-2-ethyl-N-benzyl (benzo-monoaza-15-crown-5) and the crystal structure of its sodium perchlorate complex(Springer, 2003) Özbey, S; Kaynak, FB; Togrul, M; Demirel, N; Hosgören, HA new complex of a chiral monoaza-crown ether, [R-(-)-2-ethyl-N-benzyl-4,7,10,13-tetraoxa-8,9-benzo-1-azacyclopentadec-8-ene.NaClO4], has been prepared and studied by x-ray diffraction. The compound crystallizes in space group P2(1) with cell dimensions a = 8.721(1), b = 16.318(2), c = 8.905( 1) Angstrom, beta = 100.80(1)degrees. The sodium cation is heptacoordinated and located significantly out of the best plane of the macrocycle ring. The donor atoms of the macrocycle are in the half-chair arrangement.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.
