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SALAN, ÜMİT

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SALAN

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ÜMİT

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2005 - 20093
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    The synthesis and complexation study of some novel 3-methoxyphenyl chromenone crown ethers using conductometry
    (ELSEVIER SCI LTD, 2006) SALAN, ÜMİT; Gunduz, C; Salan, U; Ozkul, N; Basaran, I; Cakir, U; Bulut, M
    7,8-Dihydroxy-3-(3,4-dimethoxyphenyl)-2H-chromenoiies, 7,8-diliydroxy-3-(3,5-dimethoxyphenyl)-2H-chromenones and 7,8-dihydroxy-3-(3,4,5-trimethoxypheiiyl)-2H-chromenones, o-diliydroxy-3-iiiethoxyphenyicoumarins, were prepared from 2,3,4-trihydroxybenzaldehyde and corresponding methoxyphenylacetic acid in NaOAc/Ac2O, respectively. 3-Methoxyphenyl-7,8-dihydroxy-2H-chromenone reacted with the polyethylene glycol ditosylate or dichloride in CH3CN/alkali carbonate to afford [12]crown-4, [15]crown-5 and [18]crown-6-chromonones. The chromatographically purified novel chromenone crown ethers were identified with IR, H-1 NMR, 13 C NMR and low and high resolution mass spectroscopy and elemental analysis. Stability constants for the 1:1 complexes of Na+ and K+ with different substituted methoxyphenyl derivatives of coumarino[12]crown-4, coumarino[15]crown-5 and coumarino[18]crowti-6 (5a-5i) have been determined by conductometry at 25 degrees C in a binary solvent, dioxane/water. For all the coumarino crown ether derivatives, the stability constant decreases for K+ ion compared to Na+ ion. The selectivity sequence of these crown ethers in dioxane/water has showed an irregular order with respect to their cavity size. (c) 2005 Elsevier Ltd. All rights reserved.
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    Synthesis and characterization of a new trans-2,2 '-azoquinoxaline bridged bisphthalocyanine
    (PERGAMON-ELSEVIER SCIENCE LTD, 2005) SALAN, ÜMİT; Salan, U; Altindal, A; Bulut, M; Bekaroglu, O
    A new trans-2,2'-azoquinoxaline bridged bisphthalocyanine was synthesized from the corresponding quinoxaline-2(1 H)one oxime, which can be obtained by the reaction of s-trans-chloroethanedial with 2-(3,4-diaminophenoxy)-9,16,23-tri(hexylthio)phthalocyanine zinc(II). 2-(3,4-Diaminophenoxy)-9,16,23-tri(hexylthio)phthalocyanine zinc(II) was synthesized by reduction of 2-(4-amino-3-nitrophenoxy)-9,16,23-tri(hexylthio)phthalocyanine zinc(II). Novel compounds were characterized by elemental analysis, UV/vis, IR and H-1 NMR spectroscopy. The conductivity and the humidity sensing properties of spin coated films of these compounds were investigated by measuring the complex impedance spectra at different humidities. Films of the final product show Up to 10(3) orders of magnitude higher conductivity than the starting and intermediate compounds. The results indicate that the presence of water vapour always leads to a drop in the real and imaginary part of the complex impedance. At room temperature, the capacitance of the films exhibits reversible increase with relative humidity, which makes these films attractive for humidity sensing applications. (c) 2005 Elsevier Ltd. All rights reserved.
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    The synthesis of novel 4-(3,4-dimethoxyphenyl)chromenone-crown ethers and their cation binding, as determined using fluorescence spectra
    (TAYLOR & FRANCIS LTD, 2009-12-01) SALAN, ÜMİT; Gunduz, Cihan; Salan, Umit; Bulut, Mustafa
    The complexation of naftifine (NF) and terbinafine (TB) with cyclodextrins (CDs) has been investigated by UV/visible and 1H NMR spectroscopy, ROESY techniques and also ESI-MS. Both drugs form 1:1 inclusion complexes with all the CDs tested except with -CD, as deduced from the Benesi-Hildebrand plots and confirmed by ESI-MS and NMR spectroscopy (Job plot method). The K11 values for NF decrease in the order -CDmethylated -CD2-hydroxypropyl--CD-CD. The determination of the enthalpy and entropy provides information about the main driving forces in the process. The stability constants of the complexes NF--CD, TB--CD and TB--CD determined by 1H NMR spectroscopy are in agreement with the values obtained by UV. For TB--CD, the value is higher, due to the fact that the length of the TB aliphatic chain allows a deeper inclusion of the naphthalene group inside the corresponding -CD molecule, according to the 2D ROESY experiments.