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Öğe Crystal structure and conformational analysis of 1-[N-(2-bromophenyl)]naphthaldimine(Elsevier Science Bv, 2003) Ünver, H.; Durlu, T.N.1-[N-(2-bromophenyl)]naphthaldimine (C17H12NOBr) (1) was synthesised and its crystal structure was determined. The compound 1 is orthorhombic, space group P2(1)2(1)2(1) with a = 12.653(2), b = 13.7311(14), c = 7.9799(12) Angstrom, V = 1386.4(4) Angstrom(3), Z = 4, D-c = 1.563 g cm(-3), mu(Mo K-alpha) = 2.959 mm(-1), R = 0.032 for 499 reflections I > 2sigma(I)]. There is an intramolecular hydrogen bond of distance 2.473(3) A between the hydroxyl oxygen atom and imine nitrogen atom, the hydrogen atom essentially being bonded to the oxygen atom. Minimum energy conformation was calculated as a function of torsion angle theta(C10-C11-N1-C12) varied every 5 degrees. The optimized geometry of the crystal structure corresponding to the non-planar conformation is the most stable conformation in all calculations. The results strongly indicate that the minimum energy conformation is primarily determined by hydrogen-hydrogen repulsions between the ortho-hydrogen atoms on the aldehyde rings. Complementary IR, H-1 NMR and UV measurements in solution and in the solid state were carried out. (C) 2003 Elsevier B.V. All rights reserved.Öğe Crystal structure and tautomerism of 1-[N-(4-iodophenyl)]aminomethylidene-2(1H)naphthalenone(Verlag Z Naturforsch, 2001) Ünver, H.; Kabak, M.; Zengin, D.M.; Durlu, T.N.1-[N-(4-Iodophenyl)]aminomethylidene-2(1H)naphthalenone (1) (C17H12NOI) has been studied by X-ray analysis, IR, H-1 NMR, UV and AM1 semi-empirical quantum mechanical methods. It crystallises in the monoclinic space group P2(1)/n with a=4.844(3), b=21.428(2), C=13.726(2) Angstrom, beta =93.07(2)degrees (R1=0.032 for 4132 reflections [I>2 sigma (I)]). The title compound is not planar and an intramolecular hydrogen bond connects O1 and N1 [2.530(4) Angstrom]. Complementary IR, H-1 NMR and UV measurements in the solution and solid states were carried out. Tautomerism and conformations of the title compound were also investigated by AM1 semi-empirical quantum mechanical calculations and the results are compared with the X-ray data.Öğe Crystal structure, spectroscopic studies and conformational analyses of 5-chloro-6-nitro-2-cyclohexylmethylbenzoxazole(Elsevier Science Bv, 2002) Ünver, H.; Arpaci, O.T.; Zengin, D.M.; Durlu, T.N.5-Chloro-6-nitro-2-cyclohexylmethylbenzoxazole (1) (C14H15O3N2Cl) has been studied by using an elemental analysis, IR, 5-Chloro-6-nitro-2-cyclohexylmethylbenzoxazole (1) ( H-1 NMR, X-ray analysis and AMI semi-empirical quantum mechanical methods. It crystallizes in the monoclinic space group P2(1)/c with a = 8.6844(1), b = 5.7169(1), c = 28.8156(1) Angstrom, beta = 92.063(1)degrees, V= 1429.70(3) Angstrom(3), Z = 4, D-c 1.369 g cm(-3), mu(Mo K-alpha) = 0.276 mm(-1) and F(000) = 616. The structure was solved by direct methods and refined to R = 0.0542 for 953 reflections [I > 2sigma-(I)]. The title compound is not planar. Minimum energy conformations from AM1 were calculated as a function of theta(1)(O1-C7-C8-C9), theta(2)(N2-C7-C8-C9), theta3(C7-C8-C9-C10) and theta4(C7-C8-C9-C14) varied every 5degrees. The optimized geometry of the crystal structure corresponding to the non-planar conformation is the most stable conformation in all calculations. (C) 2002 Elsevier Science B.V. All rights reserved.Öğe The investigation of nonlinear optical properties of N-(3-fluorophenyl)naphthaldimine(Elsevier, 2005) Ünver, H.; Karakaş, A.; Elmalı, A.; Durlu, T. N.A new ligand N-(3-fluorophenyl)naphthaldimine (C17H12NOF) has been synthesized. The physical properties and structure of this ligand have been characterized by X-ray diffraction analysis, elemental analysis, FT-IR, H-1-NMR and UV-visible spectroscopies. It is found that the title compound has solvatochromic behavior in the UV and visible regions, implying non-zero microscopic first hyperpolarizability. The electric dipole moment (mu) and the first hyperpolarizability (beta) values of the investigated molecule have been computed using ab initio quantum mechanical calculations (finite field second-order Moller Plesset perturbation theory). The calculation results also reveal that the synthesized molecule might have microscopic nonlinear optical (NLO) behavior with non-zero values. (C) 2004 Elsevier B.V. All rights reserved.Öğe Keto-enol tautomerism, conformations, and structure of 1-[N-(4-chlorophenyl)]aminomethylidene2(1H)naphthalenone(Springer/Plenum Publishers, 2001) Ünver, H.; Kabak, M.; Zengin, D.M.; Durlu, T.N.1-[N-(4-chlorophenyl)]aminomethylidene-2(1H)naphthalenone (C17H12NOCl) (1) was synthesized and the crystal structure was determined. Compound I crystallizes in the monoclinic space group P2(1)/n with a = 4.761(3) Angstrom, b = 20.347(1) Angstrom, c = 13.773(2) Angstrom, beta = 92.89(3)degrees, V = 1332.4(3) Angstrom(3), Z = 4, D-c = 1.404 g cm(-3), mu(Mo Kalpha) = 0.28 mm(-1), and R = 0.036 for 2680 reflections [I > 2sigma(I)]. Molecule I is not planar, and the dihedral angle between the naphthaldeyde plane A [Cl-C11, 01] and the 4-chloroaniline plane B [C12-C17, C11, N1] is 20.1(3)degrees. An intramolecular hydrogen bond occurs between the hydroxyl oxygen and imine nitrogen atoms [2.528(3) Angstrom]. IR, H-1 NMR, and UV measurements and AM1 semiempirical quantum mechanical calculations support the keto form found in the X-ray structure.Öğe Synthesis, spectroscopic studies, crystal structure and conformation analysis of N-(2-fluoro-3-methoxy)-salicylaldimine(Walter De Gruyter Gmbh, 2002) Ünver, H.; Kendi, E.; Güven, K.; Durlu, T.N.The new Schiff base ligand N-(2-fluoro-3-methoxy)-salicylaldimine (C14H12NO2F) (1) has been synthesised and studied by using, IR, H-1 NMR, C-13 NMR, UV-visible, GGMS techniques, X-ray structure analysis and AM1 semi-empirical quantum mechanical methods. Compound I crystallises in the orthorhombic space group P2(1)2(1)2(1) with a = 12.5461(1), b = 18.0495(1), c = 5.2615(1) Angstrom. An intramolecular hydrogen bond connects O1 and N1 [2.575(2) Angstrom], the hydrogen atom being bonded essentially to the oxygen atom. Minimum energy conformations were calculated as a function of two torsion angles theta(1) (C6-C7-C8-N1) and theta(2) (C7-C8-N1-C9), varied every 10 degrees. The optimized geometry of the crystal structure corresponding to the non-planar conformation is the most stable conformation in all calculations. The results strongly indicate that the minimum energy conformation is primarily determined by hydrogen-hydrogen repulsions between the ortho-hydrogen atoms on the aldehyde rings. Complementary IR, H-1 NMR and UV measurements in solution and in the solid state were carried out.
