Yazar "Tahir, MN" seçeneğine göre listele

Listeleniyor 1 - 5 / 5
  • Küçük Resim Yok
    Öğe
    (1E,3Z,5E)-2,5-diaza-1,6-bis(dimethylamino)-1,3,5-hexatriene-3,4-dicarbonitrile
    (Int Union Crystallography, 1996) Kucukbay, H; Cetinkaya, E; Ulku, D; Tahir, MN
    The title structure consists of discrete C10H14N6 molecules which have a cis configuration and an extended conjugation. The molecules are slightly distorted from planarity.
  • Küçük Resim Yok
    Öğe
    cis-1,1'-Dimethyl-3,3'-diphenyl-2,2'-biimidazolidinylidene
    (Munksgaard Int Publ Ltd, 1997) Ulku, D; Tahir, MN; Cetinkaya, B; Ozdemir, I
    The structure of the air-sensitive title compound consists of C20H24N4 molecules connected through a hydrogen bond. Neither the molecule as a whole nor the individual five-membered rings have a planar geometry. The dihedral angle between the best planes of the two phenyl rings is 50.87 (14)degrees. Weak intermolecular hydrogen bonding is observed between a C atom and an imidazolidine N atom.
  • Küçük Resim Yok
    Öğe
    Synthesis of a water-soluble carbene complex and its use as catalyst for the synthesis of 2,3-dimethylfuran
    (Elsevier Science Sa, 2001) Özdemir, I; Yigit, B; Cetinkaya, B; Ülkü, D; Tahir, MN; Arici, C
    1,1,3,3'-Tetrakis(p-dimethylaminobenzyl)-2,2'-biimidazolidinylidene, L-2(R) (R = CH2C6H4NMe2-p) which contains four peripheral NMe2 substituents, was obtained from 4-dimethylaminobenzaldehyde by a three-step reaction sequence, and was used for the preparation of imidazolidin-2-ylidene Ru(II) and Rh(I) complexes 1 and 2. Etherial HCl readily protonates the NMe2 functionality on the carbene ligand of 1 to give the corresponding salt, 1'; whereas the reaction of 2 with HCl gave a hygroscopic and ill-defined rhodium species. In aqueous solution the salt 1' is an efficient and active catalyst for intramolecular cyclisation of (Z)-3-methylpent-2-en-4-yn-1-ol into 2,3-dimethylfuran. The catalyst 1' could be recovered by simple phase separation and the catalytic reaction was maintained for five different runs. All of the new compounds were characterised by elemental analyses, IR and NMR spectroscopy and the molecular structure of I was determined by X-ray crystallography. (C) 2001 Elsevier Science B.V. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Synthesis of cis- and trans-dichloro(dimethylphenylphosphine) x-(1-methyl-1,4,5,6-tetrahydropyrimidine)platinum(II) and their spectral and structural characterization
    (Elsevier Science Sa, 1998) Cetinkaya, B; Ozdemir, I; Tahir, MN; Ulku, D
    Interaction of [{Pt(mu-Cl)Cl(PMe2Ph)}(2)] with 1-methyl-1,4,5,6-tetrahydropyrimidine, L (R = Me), in boiling toluene produced a mixture of cis- and trans- isomers of [PtCl2(PMe2Ph){N = CH(Me)CH2CH2CH2}] trans-complex 2 isomerizes to give thermody-namically more stable corresponding cis-complex 1 in boiling ethanol. Spectroscopic and X-ray diffraction data permit generalizations about cis- and trans- isomeric pairs to be made. In addition, the trans influence of the ligand L is reliably assessed. (C) 1998 Elsevier Science S.A. All rights reserved.
  • Küçük Resim Yok
    Öğe
    Synthesis of tetraaminoalkenes containing the reduced pyrimidine skeleton and the x-ray molecular structure of 1,1'-ethylene-3,3'-dibenzylbi(hexahydropyrimidin-2-ylidene)
    (Royal Soc Chemistry, 1996) Alici, B; Cetinkaya, E; Cetinkaya, B; Ulku, D; Tahir, MN
    Deprotonation of a 1,1'-bridged bis(1,3-diaikyl-1,4,5,6-tetrahydropyrimidinium) diiodide with NaH gives in high yield a tetraaminoalkene 4, whereas the corresponding non-bridged tetrahydropyrimidinium iodide reacts with NaH only in the presence of KOBu; the title bridged tetraaminoalkene 4f was structurally characterized by single-crystal X-ray diffraction.