Makale 2000-2009 yılları
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Browsing Makale 2000-2009 yılları by Publisher "De Gruyter"
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Item Crystal structure and magnetic exchange interaction in a binuclear copper(II) schiff base complex with a bridging m-phenylenediamine ligand(De Gruyter, 2005) Zeyrek, C. Tuğrul; Elmalı, Ayhan; Elerman, Y.; Svoboda, I.; 0000-0001-6744-7841; TAEK-ANAEMCondensation of 2-hydroxy-3-methoxybenzaldehyde with m-phenylenediamine (1,3-diaminobenzene) (m-pda) gives the ligand [N,N′-bis(2-hydroxy-3-methoxybenzylidene)-1,3-diaminobenzene] which reacts with cupric acetate to give the complex [Cu2(L-m-pda)2]·2H2O, [L = 2-hydroxy-3- methoxybenzaldehyde)]. The molecular structure of the complex [Cu2(L-m-pda)2]·2H2O has been determined by single-crystal X-ray analysis. (C44H40Cu2N4O8)·2H2O, triclinic, space group P1̄. Two [Cu(L-m-pda)] fragments, related by an inversion center, are connected by m-phenylene groups to form a binuclear unit. The coordination geometry around each copper(II) can be described as a distorted tetrahedron formed by the N2O2 donor set of the Schiff base ligands. The intramolecular Cu···Cu separation is 7.401(6) Å. The magnetic susceptibility of the complex in the 5 - 301 K temperature range can be rationalized by the parameters J = −0.4 cm−1 and g = 2.17. This indicates a weak intramolecular antiferromagnetic interaction. Extended Hückel molecular orbital (EHMO) calculations have been performed in order to gain insight into the molecular orbitals that participate in the super-exchange pathway.Item Iron(III) induced imidazolidine ring hydrolysis of binucleating schiff base ligand: synthesis, crystal structures, spectroscopic properties and conformational study of a new μ-bis(tetradentate) schiff base and its mononuclear iron(III) complex(De Gruyter, 2005-05) Zeyrek, C. Tuğrul; Elmalı, Ayhan; Elerman, Y.; 0000-0001-6744-7841; TAEK-ANAEMThe μ-bis(tetradentate) ligand, [C27H26Cl3N4O4], H3L′, 1,3-bis[N-(5-chloro-2-hydroxybenzylidene)- 2-aminoethyl]-2-(5-chloro-2-hydroxyphenyl)imidazolidine and its mononuclear iron(III) complex, [Fe(L)](ClO4), L = N, N′-bis(5-chloro-2-hydroxybenzylidene)-triethylenetetramine have been synthesized and their crystal structures determined. Minimum energy conformations of the ligand were calculated (MOPAC, AM1) as a function of two torsion angles and the results compared with optimized crystal structure. The ligand (H3L′) reacts with Fe(ClO4)2 · 6H2O in aqueous methanol to form the mononuclear [Fe(L)](ClO4) complex with the imidazolidine ring cleaved by hydrolysis. The complex has an N4O2 donor atom set forming a distorted octahedral coordination geometry around the metal atom as established from a crystal structure determination. The terminal oxygen donor atoms occupy cis positions, and the remaining four nitrogen atoms (two cis amine and two trans imine) complete the coordination sphere.Item The synthesis, crystal structure and spectroscopic properties of a dinuclear μ–pyrazolato–N,N’–bridged dinickel(II) complex of 1,3-bis(salicylideneamino)propan–2–ol(De Gruyter, 2004) Zeyrek, C. Tuğrul; Elmalı, Ayhan; Elerman, Y.; 0000-0001-6744-7841; TAEK-ANAEMThe title compound [Ni2(L)(3,5 prz)], prz = pyrazolate with the formally pentadentate ligand L = 1,3-bis(salicylideneamino)propan-2-olate, was synthesized and identified using elemental analysis and IR spectroscopy. It crystallizes in the monoclinic space group P21/c with cell parameters a = 29.873(4), b = 11.131(2), c = 13.166(3) Å , β = 107.770(10)°, V = 4169.0(13) Å3, Z = 4, Dcal = 1.618 Mg/m3. The nickel ions are bridged by the alkoxo group of the ligand and the N atoms of the μ-pyrazolate group. Each nickel(II) ion is coordinated by two N atoms and two O atoms, forming a square with trans-N2O2 geometry. The Ni···Ni distance and the Ni−O−Ni angle are 3.371(1) Å and 126.4(1)°, respectively.