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  • Küçük Resim
    Öğe
    4,4,6,6-Tetra­chloro-4a′,8′-di­hydro­dinaphtho­[2,1-c′;2,1-g′]-2λ5,4λ5,6λ5-cyclo­triphosphazene-1-spiro-1′-[2,5,8a,1]­diox­aza­phospha­naphthalene
    (Int Union Crystallography, 2004) Tercan, Barış; Hökelek, Tuncer; Işıklan, Muhammed; Ilter, Elif E.; Kılıç, Zeynel
    The title compound, C22H15Cl4N4O2P3, is a spiro phosphazene derivative with two bulky naphthalene rings. The phosphazene and the two six-membered N/O rings are not planar. The aliphatic C atom (in ArCH-OAr) and the N atom (in ArCH2-N), which has a pyramidal geometry, are capable of representing stereogenic centres.
  • Küçük Resim
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    Crystal structure of 1-[N-(6-methyl-2-pyridyl)aminomethylidene] 2(1H)-naphthalenone
    (Japan Soc Analytical Chem, 2000) Hökelek, Tuncer; Işıklan, Muhammed; Kılıç, Zeynel
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  • Küçük Resim
    Öğe
    Microwave-assisted and conventional synthesis and stereogenic properties of monospirocyclotriphosphazene derivatives
    (Pergamon-Elsevier Science Ltd, 2010) Işıklan, Muhammet; Sonkaya, Ömer; Çoşut, Bünyemin; Yeşilot, Serkan; Hökelek, Tuncer
    The reactions of hexachlorocyclotriphosphazene, N3P3Cl6, with N/O donor type N-alkyl or (aryl)-o-hydroxybenzylamines HO(C6H4)CH2NHR(Ar), [R(Ar) = C(CH3)(3) (1), Ph (2)] produce monospirocyclic tetra-chlorocyclotriphosphazenes (1a and 2a). The geminal substituted cyclotriphosphazenes (1b, 1d, 2b and 2d) are obtained from the reactions of 1 equiv. of la and 2a with 2 equiv. of pyrrolidine or morpholine in THF, while the fully substituted phosphazenes (1c, 1e, 2c and 2e) are formed from the reactions of 1a and 2a with the excess pyrrolidine or morpholine in toluene, between 24 and 48 h. The microwave-assisted reactions of la and 2a with excess pyrrolidine or morpholine in toluene afford the fully substituted products with higher yields than those which were obtained by conventional methods. The structural investigations of the compounds have been verified by elemental analyses, ESI-MS, FTIR, H-1, C-13, P-31 NMR and HETCOR techniques. The crystal structure of 2a is determined by X-ray crystallography and the phosphazene ring is in the flattened boat form. Compounds 1b, 1d, 2b and 2d in which the spiro aryloxy moiety provides the one centre of chirality exist as racemates and the chirality has been confirmed by P-31 NMR spectroscopy on addition of a chiral solvating agent (CSA), (S)-(+)-2,2,2-tri-fluoro-1-(9'-anthryl)ethanol. (C) 2010 Elsevier Ltd. All rights reserved.
  • [ X ]
    Öğe
    Phosphorus-nitrogen compounds. 14. Synthesis, stereogenism, and structural investigations of novel N/O spirocyclic phosphazene derivatives
    (Amer Chemical Soc, 2007) İlter, Elif Ece; Asmafiliz, Nuran; Kılıç, Zeynel; Işıklan, Muhammet; Hökelek, Tuncer; Çaylak, Nagihan; Şahin, Ertan
    The reactions of hexachlorocyclotriphosphazatriene, N3P3Cl6, with N/O donor-type N-alkyl-o-hydroxybenzyl- and o-hydroxynaphthylamines result in novel mono-(3a, 4a and 4b), di- (5a and 5b), and tri- (3b, 6a, and 6b) spirocyclic phosphazene derivatives. The tetrakis-pyrrolidinophosphazene, 3b, has been obtained from the reaction of partly substituted compound 3a with the excess pyrrolidine in tetrahydrofuran. The relationship between the endocyclic NPN (alpha) and exocyclic NPO (alpha') bond angles of the analogous spirocyclic phosphazenes with the delta P shifts of NPO phosphorus atoms have been presented. It was observed that there is a linearity between alpha angles and delta P shifts, while no linear relationship has been observed for alpha' angles. In addition, we have found the correlation between Delta(P-N) and delta(NPO) shifts, which implies a linear relationship. Delta(P-N) = (a-b), where a and b are the average lengths of two adjacent P-N bonds. The structural investigations of all of the compounds have been made by elemental analyses; mass spectrometry; Fourier transform infrared spectroscopy; one-dimensional H-1, C-13, and P-31 NMR; distortionless enhancement by polarization transfer; and two-dimensional correlation spectroscopy, heteronuclear shift correlation, and heteronuclear multiple-bond correlation homo- and heteronuclear correlation techniques. The solid-state structures of 3a, 4a, 4b, and 5a have been determined by X-ray crystallographic techniques. The asymmetric units of compounds 3a and 4a contain two independent molecules, and 3a has strong intermolecular N-H center dot center dot center dot N hydrogen bonds linking three phosphazene rings. The molecular structure of 6a looks like a propeller where the chemical environment of P1 is different from that of P2 and P3. On the other hand, compounds 5a and 5b are expected to exist as cis- or trans-geometric isomers and to be in cis (meso) or trans (racemic) configurations. The crystallographic and preliminary chiral solvating agents results show that both of them are trans (racemic). In addition, 6a and 6b are also expected to exist as cis-trans-trans- and cis-cis-cis-geometric isomers; both of them are found to be in cis-trans-trans geometries. According to the two-dimensional spectroscopic data, the possible conformations of 3a and 4a in CDCl3 are the same with the solid-state structures.