Memet Şekerci

THE SYNTHESIS AND SPECTRAL CHARACTERIZATION OF NEW Cu(II), Ni(II), Co(III), AND Zn(II) COMPLEXES WITH SCHIFF BASE

ABSTRACT Cu(II), Ni(II), Co(III) and Zn(II) complexes with Schiff base have been prepared. Ligand is derived from condensation of 1,2-bis(p>-aminophenoxy)ethane and 2- hydroxynaphthalin-1-carbaldehyde. The complexes have been characterized by elemental analyses, ΛM, IR, UV-VIS, 1H NMR, 13C NMR and magnetic measurements. The ligand is coordinated to the central metal as a tetradentade ONNO ligand. The four bonding sites are the azomethine nitrogen and aldehydic -OH groups.

NOVEL COMPLEXES OF MANGANESE(III), COBALT(II), COPPER(II), AND ZINC(II) WITH SCHIFF BASE DERIVED FROM 1,2-BIS(p-AMINO-PHENOXY)ETHANE AND SALICYLALDEHYDE

Several new complexes of the Schiff base obtained by the condensation of 1,2-bis(p-aminophenoxy)ethane with salicylaldehyde were synthesized. The complexes have been characterized by elemental analyses, magnetic measurements, 1H NMR, UV-VIS and IR spectra. The ligand is coordinated to the central metal as a tetradentade ONNO ligand. The four bonding sites are the azomethine nitrogen and the o-OH groups.

Molecular structure and vibrational bands and chemical shift assignments of 4-allyl-5-(2-hydroxyphenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione by DFT and ab initio HF calculations

The title molecule, 4-allyl-5-(2-hydroxyphenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (C(11)H(11)N(3)OS), was synthesized and characterized by IR-NMR spectroscopy and single-crystal X-ray diffraction. The compound crystallizes in the monoclinic space group is P2(1)/c, a=9.0907(5)A, b=9.1288(7)A, c=13.6222(7)A, alpha=90 degrees , beta=98.442 (4), gamma=90 degrees and V=2683.7(6)A(3), F(000)=488, D(x)=1.386 g/cm(3). In addition to the molecular geometry from X-ray experiment, the molecular geometry, vibrational frequencies, gauge including atomic orbital (GIAO) (1)H and (13)C chemical shift values of the title compound in the ground state have been calculated using the Hartree-Fock (HF) and density functional method (DFT/BLYP and DFT/B3LYP) with 6-31G(d) basis set. To determine conformational flexibility, molecular energy profile of the title compound was obtained by HF/6-31G(d) calculations with respect to selected degree of torsional freedom, which was varied from -180 degrees to +180 degrees in steps of 10 degrees . Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO), and several thermodynamic properties were performed by the HF and DFT methods.

Synthesis and Characterization of Cu(II), Co(II), Ni(II), and Zn(II) Complexes of a Schiff Base Derived from 1‐Amino‐5‐benzoyl‐4‐phenyl‐1H‐pyrimidine‐2‐one and 3‐Hydroxysalicylaldehyde

Cu(II), Co(II), Ni(II) and Zn(II) metal complexes of a new heterocylic Schiff base derived from 1‐amino‐5‐benzoyl‐4‐phenyl‐1H‐pyrimidine‐2‐one with 3‐hydroxy‐salicylaldehyde have been synthesized and characterized on the basis of elemental analyses, electronic, IR and 1H NMR spectra, molar conductivity measurements, magnetic moment measurements and thermogravimetric analyses (TGA). It has been found that the Schiff base behaves as a neutral bidentate (NO) or tridentate (ONO) ligand forming chelates with 1:2 (metal:ligand) stoichiometry and octahedral geometry. The conductivity data for the Ni(II) complex is consistent with that expected for a weak electrolyte.

THE SYNTHESIS, CHARACTERIZATION AND CONDUCTANCE STUDIES OF NEW Cu(II), Ni(II) AND Zn(II) COMPLEXES WITH THE SCHIFF BASE DERIVED FROM 1,2-BIS-(o-AMINOPHENOXY)ETHANE AND SALICYLALDEHYDE

Cu(II), Ni(II) and Zn(II) complexes with the Schiff base derived from 1,2-bis-(o-aminophenoxy)ethane with salicylaldehyde have been prepared. The complexes have been characterized by elemental analysis, magnetic measurements, 1H NMR, 13C NMR, UV, visible and IR spectra as well as conductance measurements. The ligand is coordinated to the central metal as a tetradentate ONNO ligand. The four bonding sites are the central azomethine nitrogen and aldehydic OH groups. The ligand was used for complexation studies. Stability constants were measured by a conductometric method. Furthermore, the stability constants for complexation between ZnCl2 and Cu(NO3)2 salts and N,N′-bis(salicylidene)-1,2-bis-(o-aminophenoxy)ethane (H2L) in 80% dioxane/water and pure methanol were determined from conductance measurements. The magnitudes of these ion association constants are related to the nature of the solvation of the cation and the complexed cation. The mobilities of the complexes are also dependent, in part, upon solvation effects.

The Synthesis and Co(II), Ni(II), Cu(II) and Uo2(Vi) Complexes of 1,2-O-Benzal-4-Aza-7-Aminoheptane

Abstract 1,2-O-Benzal-4-aza-7-aminoheptanc (L) has been synthesized starting from 1-chloro-2,3-O-benzalpropane, which has been prepared from the reaction of epichlorohydrin and benzaldehydc. The complexes of this ligand with Co(II), Ni(II), Cu(II) and UO2(VI) salts were prepared. The structures of the ligand and its complexes are proposed based on elemental analyses, 1R, UV-V1S, 1H and 13C NMR spectra, magnetic susceptibility measurements, thermogravimetric analyses (TGA) and differential thermal analyses (DTA).

Synthesis, Physico‐Chemical Characterization, and Stability Constants of Metal Complexes of Pyridine‐2‐carbaldehyde Thiosemicarbazone

The synthesis, physico‐chemical properties and complexes with transition element cations of pyridine‐2‐carbaldehyde thiosemicarbazone (L) are reported. The synthesis and structural analysis of L, its complexes with MCl2 (M = Mn(II), Zn(II), Cd(II)) and MıCl3 (Mı = Cr(III), Co(III)) salts are reported. Their general formulas are [M(L)3]Cl3 · 3H2O [M = Cr(III) and Co(III)], [M(L)(H2O)Cl]Cl [M = Zn(II) and Mn(II)] and [Cd(L)Cl2)] · H2O. Mn(II), Zn(II), Cd(II) complexes with a metal‐ligand ratio 1:1 and Cr(III), Co(III) complexes with a metal‐ligand ratio 1:3 have been prepared. Molecular structures of these complexes were identified using elemental analyses, FT‐IR UV‐Vis, thermogravimetric (TGA) and conductivity techniques. The structure, along with other physico‐chemical studies, establishes that the complexes of L, except for the cobalt complex, are low‐spin. Spectroscopic analysis shows that the transition metal complexes have octahedral or tetrahedral geometry. For the Cr(III) and Co(III) complexes octahedral geometry is proposed, and the Zn(II), Cd(II) and Mn(II) complexes are proposed to be of tetrahedral geometry. The stability constants of the Zn(II) and Mn(II) complexes were determined by the Job method. The stability constants of the Zn(II) and Mn(II) complexes were found to be 8.77 × 104 M–1 and 6.40 × 105 M–1, respectively. The increase in stability constants follows the order of Zn(II) > Mn(II) and this increase is in agreement with the Irving‐Williams series.

A New Heterocyclic Schiff Base and Its Metal Complexes

Abstract Cu(II), Co(II), Ni(II), and Zn(II) metal complexes of a new SNO tridentate heterocyclic Schiff base derived from the reaction of 1‐amino‐5‐benzoyl‐4‐phenyl‐1H‐pyrimidine‐2‐thione with salicylaldehyde have been synthesized and characterized on the basis of elemental analyses, electronic, IR, and 1H NMR spectra, and also by molar conductivity measurements, magnetic moment measurements and thermogravimetric analyses (TGA). It has been found that the Schiff base behaves as a neutral tridentate SNO ligand forming chelates with 1:2 or 1:1 (metal:ligand) stoichiometry. The complexes of Co(II), Ni(II), and Zn(II) are proposed to have an octahedral structure, while the Cu(II) complex is suggested to have a square–pyramidal geometry. All of the complexes show nonelectrolytic behavior.

3‐(2‐Furyl)‐4‐(4‐methoxy­phenyl)‐1H‐1,2,4‐triazole‐5(4H)‐thione

The title compound, C13H11N3O2S, has a non-planar conformation. The dihedral angles are 3.41 (8) and 85.48 (7)° between the triazole ring plane and the furan and benzene ring planes, respectively. The crystal packing is stabilized by several hydrogen bonds.

Synthesis of (Z,Z)-1, 2-dihydroxyimino-3, 6-diamlno-8, 9-O,O-cyclopentylidenenonane-8, 9-diol and Its Complexes with Copper(II), Nickel(II), Cobalt(II) and Uranyl(VI)

Abstract The new yic-dioxime ligand, (Z, Z)-1, 2-dihydroxyimino-3, 6-diamino-8, 9-O, O-cyIopentylidenenonane-8, 9-dioI (LH2) was synthesized by treating 1, 3-diamino-5, 6-O, O-cylopenlylidenehexane-5, 6-diol (R-NH2) with anti-chloro-glyoxime in the presence of a base, e. g. triethylaminc. vic-Dioximes have been found to be in the Z, Z-form according to 1H NMR and 13C NMR data. Mononuclcar complexes having ametal-ligand ratio of 1:2 have been prepared with Co(II), Cu(II) and Ni(II) salts. However, the metal-ligand ratio and structure of the UO2(VI) complex was found to be 1:1 and dinuclear. The ligand and its complexes were characterized by magnetic susseptibility, elemental analyses, IR, UV-Vis., 1H NMR, 13C NMR, TGA and DTA studies. Structures for the complexes are suggested.