Orhan Atakol

Corrosion inhibition of mild steel with Schiff base compounds in 1 M HCl

The corrosion inhibition of mild steel with Schiff base compounds derived from salicylaldehyde and the corresponding amine was studied in relation to the concentration using electrochemical techniques. The maximum inhibition efficiency (η) was obtained for the N-(2-methyl phenyl)salicyaldimine compound with the three-electrochemical techniques applied. The N-(2-methyl phenyl)salicyaldimine and N-(2-methoxyphenyl)salicyaldimine compounds were seen to obey the Temkin adsorption isotherm whereas N-(2-hydroxyphenyl)salicyaldimine obeyed the Langmuir adsorption isotherm.

Some new NiZn heterodinuclear complexes: square-pyramidal nickel(II) coordination

A new series of heterodinuclear nickel(II)zinc(II) complexes, [NiL·ZnCl 2 ·4-picoline] ( 1 ), [NiLDM·ZnCl 2 ·4-picoline] ( 2 ), [NiL·ZnBr 2 ·4-picoline] ( 3 ), [NiLDM·ZnBr 2 ·4-picoline] ( 4 ), [NiLDM·ZnBr 2 ·3-picoline] ( 5 ), [NiLDM·ZnBr 2 ·3,5-lutidine] ( 6 ) and [NiL·ZnI 2 ·4-picoline] ( 7 ), where L is N , N ′-bis(salicylidene)-1,3-diaminopropane dianion and LDM is N , N ′-bis(salicylidene)-2,2′-dimethyl-1,3-diaminopropane dianion, were prepared. The complexes were characterized by elemental analysis, thermogravimetric analysis and IR spectroscopy. X-ray crystallographic analysis of complexes 1 , 2 and 4 revealed that nickel(II) ion in heteronuclear complexes had a square-pyramidal coordination sphere. It is concluded that formation of square-pyramidal nickel(II) coordination depends strongly on the concentration of methyl pyridine present in the medium and occurs when methyl pyridine/Ni ratio is below 1.5.

The non-aqueous titrimetric assay of the selected anti-inflammatory agents using tetra-n-butylammonium hydroxide as titrant.

A potentiometric titration method in non-aqueous media is proposed for the determination of some commonly used anti-inflammatory agents. The direct potentiometric titration of three anti-inflammatory agents, namely mefenamic acid, fenbufen and ibuprofen; and the indirect potentiometric titration of diclofenac sodium was carried out in acetonitrile solvent using tetra-n-butylammonium hydroxide as titrant, at 25 degrees C and under a nitrogen atmosphere. The method was found to be highly accurate and precise, having a relative standard deviation of <1.0% for all anti-inflammatory agents studied. Also, it was shown that the method could be successfully applied to the assay of commercial pharmaceuticals containing the above-mentioned anti-inflammatory agents. The validity of the method was tested by the recovery studies of standard addition to pharmaceuticals and the results were found to be satisfactory. The proposed method is simple, rapid and sufficiently precise for quality control purposes.

Synthesis and Crystal Structure of Linear Chain Homotetranuclear Complexes with N3

Mononuclear copper(II) complexes, Cu(L) [N,N′‐bis(salicylidene)‐1,3‐propanediaminato]copper(II), and Cu(LDM) [N,N′‐bis(salicylidene)‐2,2′‐dimethyl‐1,3‐propanediaminato]copper(II), were prepared from the ONNO type ligands N,N′‐bis(salicylidene)‐1,3‐diaminopropane (H2L) and N,N′‐bis(salicylidene)‐2,2′‐dimethyl‐1,3‐diaminopropane (H2LDM). These mononuclear complexes were transformed into tetranuclear complexes, [(S)Cu(L)Cu(N3)2]2 and [(S)Cu(LDM)Cu(N3)2]2 (S are solvent molecules, DMSO, DMF, THF, dioxan), with N3 ‐ and Cu(II) ions. All complexes were characterized by elemental analyses and IR spectroscopy. A molecular model of the complex [(DMSO)Cu(L)Cu(N3)2] was obtained by single crystal x‐ray diffraction methods.

Assessment of air pollution genotoxicity by RAPD in Evernia prunastri L. Ach. from around iron-steel factory in Karabük, Turkey

Lichens are widely used in biomonitoring studies of air pollution, either as bioindicators of air quality or as bioaccumulators of atmospheric deposition. Over the past decade, several molecular techniques have been developed to provide information on diversity, genotoxicology, genetic relationships, etc. The heavy metal contents of Evernia prunastri samples were determined by atomic absorption spectrometry. The Random Amplified Polymorphic DNA Polymerase Chain Reaction (RAPD-PCR) method was used to describe the pattern of DNA band variation in the samples influenced by the environmental pollution. The study was designed to describe the level of pollution in an area contaminated with smoke and waste from an iron-steel factory, and to reveal the level of potential genotoxic agents around this source of pollution. The study also examined the suitability of the lichen samples for the detection of genotoxicity.

N-(2-Hydroxyphenyl)salicylaldimine

The title compound, 2-(salicylideneamino)phenol, C 13 -H 11 NO 2 , a potential tridentate ligand, has two crystallographically independent molecules in the asymmetric unit, one of which is disordered. Intramolecular hydrogen bonds occur between the pairs of atoms 0(16) and N(8) [2.625 (7) A], and O(1) and 0(16) [3.571(7) A], the H atoms essentially being bonded to the O atoms.

Synthesis and crystal structure of two dimeric cadmium(II) complexes bonded with pseudohalides, 1.1 and 1.3 bonding

Abstract Two different complexes were obtained from (dmpp) and Cd(II) ions with the aid of pseudohalide ions in non-aqueous solvents. The dinuclear complex formed with thiocyanate ions show, using XRD, to posses two 1.3 bond μ bridges [CdL(SCN)2]2. The other dinuclear complex was also seen to form with cyanate ions but with the μ-bridge in a 1.1 position [CdL(OCN)2]. All Cd atoms are located in a distorted octahedral environment in 1 and 2 complexes. The Cd…Cda distances are 6.032(4) Å in 1 and 3.704(3) Å in 2, respectively. The N—C—S and O—C—N angles are approximately linear as 178.1(3) and 178.6(3)° in 1 and 177.2(5) and 176.9(7)° in 2, respectively. The Cd—(μN,S-NCS)2—Cda bonds form a zig-zag structure in 1 and the Cd—(μO,N-OCN)2—Cda bonds form a distorted square planar in 2.

Some DI- and Trinuclear Zinc Complexes: Anion Induced Complex Formation

Abstract Complexes of N,N′-bis(salicylidene)-1,3-diaminopropane, an ONNO type ligand, with ZnX2 (X = AcO−, NO3-, Cl−, Br−, I−) salts were prepared. Molecular structures of these complexes were identified using elemental analyses, IR spectrometry and X-ray diffraction techniques. It has been observed that the reactions between zinc ions and the said ligand tend to produce polynuclear complexes and depending on the anion present either di- or trinuclear complexes are formed. Thus, it can be deduced from the results presented in this article that trinuclear complexes form when the zinc salt used was the acetate or nitrate and dinuclear complexes form if the anion in the zinc salt is a halogen.

Experimental and computational investigations of a Cadmium(II) mononuclear complex with 2,6-Bis(3,5-dimethyl-N-pyrazolyl)pyridine (bdmpp) and selenocyanate as ligands

A new cadmium (II) complex, [Cd(bdmpp)(SeCN)2(H2O)] (1) (where bdmpp = 2,6-bis(3,5-dimethyl-N-pyrazolyl)pyridine), has been synthesized and characterized by elemental and spectral (IR, 1H-NMR and 13C-NMR, UV-Vis) analyses, differential scanning calorimetry, and single crystal X-ray diffraction studies. X-ray analysis showed that the structure was crystallized in the monoclinic space group Cc with a = 9.031(2), b = 13.884(3), c = 16.910(3) Å, and Z = 4. The geometry around the cadmium atom is distorted octahedral with a CdN3Se2O setup. The N atoms of the SeCN are engaged in two strong intermolecular H-bonding interactions forming a 3D supramolecular polymeric network. The geometry and vibrational frequencies of complex 1 computed with the DFT methods (BLYP, B3LYP, B3PW91, MPW1PW91) are in better agreement with experiment than those obtained with the ab-initio method except for the bond angles. The molecular orbital diagram has been also calculated and visualized at the B3LYP/LanL2DZ level of theory.

Preparation and Characterization of PVA/Boron Polymer Produced by an Electrospinning Technique.

Abstract In this study, poly(vinyl alcohol) were cross-linked with boron in varying concentrations and blend fibers were obtained with diameters ranging from 0.3 μ to 4.0 μm with the use of electrospinning process. The resulting product was characterized by SEM, DSC, and FT-IR techniques. There is no beading tendency in either boron doped or undoped fibers. When the amount of boric acid in PVA solutions was increased the conductivity of the polymer decreased. The data indicated the existence of boron oxide in the polymeric structure and the formation of B-O-C bond. SEM micrographs reveal that higher viscosity favors the formation of thicker fibers. Boron addition seems to disturb the easy detachment of the fibers from the tip of the Taylor Cone