Yazar "Guven, K" seçeneğine göre listele

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    3,9-dimethyl-1,11-diphenyl-4,8-diaza-undecane-1,11-dione dihydrate
    (Munksgaard Int Publ Ltd, 1999) Elerman, Y; Kabak, M; Kara, H; Guven, K; Nakipoglu, C
    The title compound, C23H26N2O2. 2H(2)O, displays strong intramolecular N-H ... O [2.637(2) Angstrom] and intermolecular O-H ... O [2.763(4) and 2.842(3) Angstrom] hydrogen bonds within each salicylideneimine unit and water molecule. The Schiff base has a twofold axis passing through the central C atom and therefore adopts a cis conformation.
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    Dispersion-strengthening effect of Cu-based Mn, Al, and Zn rich alloys
    (Elsevier Science Sa, 2004) Sari, U; Agan, S; Aksoy, I; Guven, K; Kahveci, N
    In this systematic study, dispersion-strengthening effect of the Cu-25.91Mn (wt.%), Cu-26.62Mn-8.99Al (wt.%), Cu-22.17Mn-12.32Zn (wt.%) ingot alloys have been investigated. Samples were homogenized at a high fixed temperature in different periods and cooled with different cooling rates. After processes, microanalysis of the samples were interpreted by using scanning electron microscope (SEM) and weight percentages of the elements of the occurrence phases in the samples obtained by using electron dispersion spectroscopy (EDS) technique. Additionally, some characteristic properties of the heat treated samples with different conditions of Cu-Mn, Cu-Mn-Al, Cu-Mn-Zn ingot alloys were also discussed. (C) 2003 Elsevier B.V. All rights reserved.
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    The effect of nitrogen atom on double bond pyramidalization
    (Springer/Plenum Publishers, 2004) Ozen, R; Guven, K; Can, H; Balci, M
    The title compound 6-phenyl-4,6,8-triazatetracyclo[9.2.1.0(2,10).0(4,8)] tetradec-2(10)-ene-5,7-dione ( 6) has been synthesized by the addition of 4-phenyl-1,2,4-triazole-3,5-dione (PTAD) to 2,3-dimethylenebicyclo[2.2.1] heptane. The cell parameters are a = 9.991(5), b = 11.754( 9), c = 6.549( 5) Angstrom, alpha = 101.08( 7)degrees, beta = 103.31( 5)degrees, gamma = 98.24( 5) degrees. The crystal structure of 6 was determined. The obtained geometrical parameters were highly correlated with the DFT calculations. The experimentally determined folding angle of the double bond was found to be 8.44degrees. The effect of the electron-withdrawing ability of nitrogen atom on the degree of pyramidalization is discussed.
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    Intramolecular hydrogen bonding and tautomerism in 1-[N-(4-bromophenyl)]aminomethylidene-2(1H) naphthalenone
    (Kluwer Academic/Plenum Publ, 2000) Unver, H; Zengin, DM; Guven, K
    1-[N-(4-bromophenyl)]aminomethylidene-2(1H)naphthalenone (C17H12NOBr) (1) was synthesized and its crystal structure was determined. Compound (1) is monoclinic, space group P2(1)/n with a = 4.808(1) Angstrom, b = 20.617(1) Angstrom, c = 13.750(1) Angstrom, beta = 93.004(1)degrees, = 1361.11(3) Angstrom (3), Z = 4, D-c = 1.592 g.cm(-3), mu (Mo K-alpha) = 3.014 mm(-1), R = 0.051 for 1013 reflections [I > 2 sigma (I)]. There is a strong intramolecular hydrogen bond of distance 2.544(2) Angstrom between the hydroxyl oxygen atom and imine nitrogen atom, the hydrogen atom essentially being bonded to the nitrogen atom, The title molecule is not planar. X-ray crystal structure determination reveals the existence of the keto (or predominantly keto) tautomer in (1). Spectra of compound (1) were observed by IR and NMR, and UV-visible spectra of (1) were studied in different solvents and acidic media.
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    Structure of 2-{2-[3-methyl-3-(2,4,6-trimethylphenyl) cyclobutyl]-2-oxoethyl}isoindole-1,3-dione
    (Springer/Plenum Publishers, 2004) Sari, U; Yilmaz, I; Guven, K; Cukurovali, A; Aksoy, I
    2-{2-[3-Methyl- 3-(2,4,6-trimethylphenyl) cyclobutyl]-2-oxoethyl} isoindole-1,3-dione (C-24 H25NO3) was synthesized, and its crystal structure was determined by X-ray crystallographic techniques. The compound crystallizes in the triclinic space group P-1, with unit cell parameters: a = 14.109(9) Angstrom, b = 14.130( 8) Angstrom, c = 12.152( 6) Angstrom, a = 105.62( 5)degrees, beta = 113.75( 4)degrees, gamma = 98.78(5)degrees, V = 2039.8(19) Angstrom(3), D-c = 1.223 g/cm(3), and Z = 4. The crystal structure has two crystallographically independent molecules, I and II. These molecules are held together by weak intermolecular C-H ... O interactions, forming a continuous chain. The dihedral angles between the N-substituted phthalimide moiety and cyclobutane ring in molecules I and II are 60.37(14) and 68.18(18)degrees, respectively.