Canan Kazak

Structural characterization and EPR spectral studies on mononuclear copper(II) complex of saccharin with ethylnicotinate

Mononuclear copper(II) saccharinate (sac) complex containing ethylnicotinate (enc), [Cu(enc)(2)(sac)(2)(H(2)O)].1.4H(2)O has been synthesized and characterized by spectroscopic (IR, UV-vis, EPR), X-ray diffraction technique and electrochemical methods. It crystallizes in the tetragonal crystal systems with space group I4(1)cd and Z=8. The copper(II) ion presents a CuN(4)O distorted square pyramidal coordination. Based on EPR and optical absorption studies, spin-Hamiltonian and bonding parameters have been calculated. The g-values, calculated for title complex in polycrystalline state at 298 K and in frozen DMF (110K), indicate the presence of the unpaired electron in the d(x)(2)-(y)(2) orbital. The evaluated metal-ligand bonding parameters showed strong in-plane sigma and in-plane pi-bonding. Some comparisons with related structures are made and the most important features of its IR spectrum were also discussed. The cyclic voltammogram of the title complex investigated in DMF (dimethylformamide) solution exhibits only metal centred electroactivity in the potential range +/-1.25 V vs. Ag/AgCl reference electrode.

N-(4-Nitrobenzoyl)-N′-(1,5-dimethyl-3-oxo-2-phenyl-1H-3(2H)-pyrazolyl)-thiourea hydrate: Synthesis, spectroscopic characterization, X-ray structure and DFT studies

The title molecule (C19H17N5O4S·H2O) was synthesized and characterized by IR-NMR spectroscopy, MS and single-crystal X-ray diffraction. The molecular geometry, vibrational frequencies and gauge-independent atomic orbital (GIAO) 1H and 13C NMR chemical shift values of the compound in the ground state have been calculated by using the density functional theory (DFT) method with 6-31G(d) basis set, and compared with the experimental data. All the assignments of the theoretical frequencies were performed by potential energy distributions using VEDA 4 program. The calculated results show that the optimized geometries can well reproduce the crystal structural parameters, and the theoretical vibrational frequencies and 1H and 13C NMR chemical shift values show good agreement with experimental data. To determine conformational flexibility, the molecular energy profile of the title compound was obtained with respect to the selected torsion angle, which was varied from -180° to +180° in steps of 10°. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis and thermodynamic properties of the compound were investigated by theoretical calculations.

(E)-N′-(2-Hy­droxy­benzyl­idene)furan-2-carbohydrazide

In the title compound, C12H10N2O3, the dihedral angle between the benzene ring and the furan ring is 16.12 (13)°. The conformation is stabilized by an intramolecular O—H⋯N hydrogen bond. Intermolecular N—H⋯O hydrogen bonds with the keto group as acceptor lead to strands along [001]. The molecule displays a trans configuration with respect to the C=N and N—N bonds.

Supramolecular lead(II) azide complex of 2,6-diacetylpyridine dihydrazone: synthesis, molecular structure, and biological activity

The complex of 2,6-diacetylpyridinedihydrazone (L) with lead(II) and azide has been characterized by elemental analyses, FTIR, and single-crystal X-ray analysis. The Pb(C9H13N11) (1) crystallized in the monoclinic space group C2/c. The coordination of 1 exhibits a gap around the lead(II), possibly occupied by a stereochemically active electron lone pair on lead(II) resulting in a hemidirected complex. Antimicrobial activity of the complex is higher than the free ligand.

An eight-coordinate strontium complex with two tetradentate triethanolamine ligands: synthesis, IR spectra, thermal analysis and crystal structure of bis(triethanolamine)strontium(II) saccharinate

Bis(triethanolamine)strontium(II) saccharinate, [Sr(tea) 2 ](sac) 2 was synthesized and characterized by IR spectroscopy, thermal analysis and X-ray diffraction techniques. The compound crystallizes in orthorhombic system and consists of two sac anions and a complex cation, in which each tea ligand behaves as a tetradentate ligand and their configuration results in an eight-coordinate strontium(II) complex with a bicapped trigonal prism geometry. The anions and cations are linked by the intermolecular hydrogen bonds between the hydroxyl hydrogens of the tea ligands and the amine N, and carbonyl O atoms of the neighbouring sac ions, forming one-dimensional chains running parallel to c. The adjacent chains are held together by van der Waals interactions, creating a three-dimensional network. The FTIR spectra and thermal decomposition of the complex were discussed.

Synthesis of novel substituted purine derivatives and identification of the cell death mechanism.

Novel 9-(substituted amino/piperazinoethyl)adenines (4-12), 6-(substituted piperazino/amino)purines (15-27), 9-(p-toluenesulfonyl/cyclopentyl/ethoxycarbonylmethyl)-6-(substituted amino/piperazino)purines (28-34, 36, 37, 38-41) were synthesized and evaluated initially for their cytotoxic activities on liver Huh7, breast T47D and colon HCT116 carcinoma cells. N(6)-(4-Trifluoromethylphenyl)piperazine derivative (17) and its 9-(p-toluene-sulfonyl)/9-cyclopentyl analogues (28, 36) had promising cytotoxic activities. Compounds 17, 28 and 36 were further analysed for their cytotoxicity in a panel of a liver cancer cell lines. The compound 36 had better cytotoxic activities (IC50 ≤ 1 μM) than the nucleobase 5-FU and nucleosides fludarabine, cladribine, and pentostatine on Huh7 cells. Cytotoxicity induced by 36 was later identified as senescence associated cell death by SA-β-Gal assay.

Design and One-Pot and Microwave-Assisted Synthesis of 2-Amino/5-Aryl-1,3,4-oxadiazoles Bearing a Benzimidazole Moiety as Antioxidants

In this study, two new series of 2‐amino‐1,3,4‐oxadiazoles and 5‐aryl‐1,3,4‐oxadiazoles carrying a benzimidazole moiety were synthesized. The antioxidant properties of these compounds were investigated in vitro by the determination of the microsomal NADPH‐dependent inhibition of lipid peroxidation levels (LP), the microsomal ethoxyresorufin O‐deethylase activity (EROD), and DPPH radical scavenger effects. Among the tested compounds, 2‐[(2‐(4‐chlorophenyl)‐1H‐benzo[d]imidazole‐1‐yl)methyl]‐5‐(4‐fluorophenyl)‐1,3,4‐oxadiazole (9) was found to be the most active compound in all three in vitro systems.

2-[(4-Hydroxyphenyl)iminomethyl]-thiophene

The molecular structure of the title compound, C(11)H(9)NOS, has three planar moieties, two of which are rings, namely the hydroxyphenyl and the thiophene, with an angle of 20.76 (10) degrees between them. The crystal structure is stabilized by an O-H.N hydrogen bond and by C-H.O intermolecular interactions. The C.O intermolecular contact distance is 3.443 (2) A.

Synthesis and antidiabetic activity of 2,4-thiazolidindione, imidazolidinedione and 2-thioxo-imidazolidine-4-one derivatives bearing 6-methyl chromonyl pharmacophore

Numerous compounds have been prepared in order to improve the pharmacological profile of insulinotropic activities. In the present paper, we report the synthesis and the in vitro insulin releasing activity of the 6-methyl-chromonyl-2,4-thiazolidinediones (IIIa–c, IVa–c, Va–c). Compounds IIIb, IIIc, IVa–c, Va and Vc (at lower concentration; 0.001 mg/mL) were able to increase insulin release in the presence of 5.6 mmol/L glucose. In this series, the most potent compound is IVa having methyl group at N3 position of TZD ring.

Synthesis, characterization, crystal structure and thermal analysis of a copper(II) mononuclear compound with 2,6- bis (3,5-dimethyl- N -pyrazolyl)pyridine (bdmpp) and selenocyanate as ligands

A single crystal of the copper(II) compound, [Cu(bdmpp)(SeCN)2], 2, was obtained and its crystal structure was determined by X-ray diffraction methods. The complex was characterized by elemental, thermal and FTIR analysis. The FTIR analysis of the complex clearly shows the SeCN peaks at 2096 and 2061 cm−1 which did not exist in the free organic ligand (bdmpp). X-ray analysis showed that 2 crystallized in the monoclinic space group P21/c. Cu(II) has a distorted trigonal bipyramidal coordination involving three N atoms from the ligand and two N atoms from the selenocyanate group.