Ziya Erdem Koç

Complexes of Iron(III) and Chrom(III) Salen and Saloph Schiff Bases with Bridging 2,4,6-tris(4-nitrophenylimino-4′-formylphenoxy)-1,3,5-triazine

Four new trinuclear Fe(III) and Cr(III) complexes involving tetradenta Schiff bases N,N′-bis(salicylidene)ethylenediamine-(salenH2) or bis(salicylidene)-o-phenylenediamine-(saloph H2) with 2,4,6-tris(4-nitrophenylimino-4′-formylphenoxy)-1,3,5-triazine (TNPI-TRIPOD) have been synthesized and characterized by means of elemental analysis carrying out 1H-NMR., IR spectroscopy, thermal analyses and magnetic susceptibility measurements. The complexes can also be characterized as high-spin distorted octahedral Fe(III) and Cr(III) bridged by nitro. The nitro play a role as bridges for weak anti-ferromagnetic intramolecular exchange.

Synthesis of novel tripodal-benzimidazole from 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine: Structural, electrochemical and antimicrobial studies

Four new tripodal-benzimidazole derivatives were synthesized by Schiff base reaction between 2,4,6-tris(p-formylphenoxy)-1,3,5-triazine (TRIPOD) and different diamine derivatives. The structures of the obtained compounds were identified by FT-IR, (1)H NMR, (13)C NMR and UV-vis spectral data, thermal analysis and elemental analysis. Electrochemical behaviors of the compounds were studied by cyclic voltammetry in DMF including 0.1 M [NBu(4)] [PF(6)]. The voltammograms showed peaks having similar characteristics except tripodal-benzimidazole including -NO(2) derivative. In addition, their antimicrobial activities were evaluated by using the standard disk diffusion method in dimethylformamide media. The activities were determined against 4 bacteria cultures by comparing to those of gentamycin.

Synthesis and Characterization of a New Dioxime and Its Heterotrinuclear BF2 + Capped Complexes

ω‐Isonitrosoacetophenone 1, phenylglyoxime 2, chlorophenylglyoxime 1, dopaminophenylglyoxime 3 and [(salen/saloph)Fe]2O 4 have been synthesized as described in the literature procedure. [Fe(III)(salen/saloph)dopaminophenylglyoxime)] (starting complexes) have been synthesized from dopaminophenylglyoxime and tetradentate schiff bases which contain dinuclear Fe(III) oxygen‐bridges N,N′‐bis(salicylidene)ethylenediamine (salenH2) and bis(salicylidene)‐o‐phenylenediamine (salophH2). The new heterotrinuclear complexes have been obtained from starting complexes and Co(II), Ni(II), Cu(II) salts. Then, heterotrinuclear vic‐dioxime complexes containing BF2 + capped have been synthesized. The complexes have been characterized as low‐spin distorted octahedral Fe(III) bridged by o‐hydroxyphenolic groups. The o‐hydroxyphenolic groups play a role as bridges for weak antiferromagnetic intramolecular exchange. The structure of dioxime and its complexes were identified by using elemental analysis, ICP‐AES, 1H‐NMR and IR spectral data.

THE INVESTIGATION OF SECOND-ORDER NONLINEAR OPTICAL PROPERTIES OF P-NITROPHENYLAZOANILINE: SECOND HARMONIC GENERATION AND AB INITIO COMPUTATIONS

p-nitrophenylazoaniline (1) belongs to the family of compounds with conjugated bonds and delocalized π-electrons, structurally similar to the well known push-pull compound Disperse Red 1 (DR1).1 Due to the assembly of the molecule, nonlinear optical (NLO) properties are expectable and can be more or less accurately predicted. To estimate the potential for second-order NLO properties, the electric dipole moment (μ), dispersion-free dipole polarizabilities (α) and first hyperpolarizabilities (β) have been determined by density functional theory (DFT) quantum chemical calculations at B3LYP/ 6-311 + G(d, p) level. According to the computation results, the synthesized compound exhibits non-zero β values and it might have second-order NLO behavior. Title compound has been synthesized and characterized by FT-IR, 1H-NMR and UV-Vis spectroscopies. The maximum one-photon absorption (OPA) wavelengths were estimated to be shorter than 450 nm by quantum mechanical computations using the configuration interaction (CI) method. The same result was achieved by UV-Vis spectra measurements, whereas the compound exhibited good optical transparency to the visible light. Quantitative measurements of second harmonic generation (SHG) at 800 nm and 1064 nm have been performed. The relative efficiency comparable with that of KDP (kalium diphosphate) has been observed with the exciting wavelength of 1064 nm, while the other wavelength led to strong absorption of produced light by the sample. In the following more detailed study on frequency-dependent first hyperpolarizabilities using time-dependent Hartree–Fock (TDHF) method have been computed at the wavelengths used in SHG measurements.

Synthesis of novel dopamine derived multidirectional ligands from cyanuric chloride: structural and antimicrobial studies.

Two monopodal (2,4-dichloro-6-(3-hydroxytyramine)-1,3,5-triazine) and tripodal (2,4,6-(3-hydroxytyramine)-1,3,5-triazine) s-triazine derivatives were prepared through the reaction of cyanuric chloride (2,4,6-trichloro-1,3,5-triazine) and 3-hydroxytyramine hydrochloride (dopamine hydrochloride). The structures of the compounds were identified by FT-IR, 1H NMR, 13C NMR, thermal analysis and elemental analysis. Their antimicrobial activities were carried out using the broth microdilution method in dimethyl sulfoxide (DMSO): Phosphate Buffered Saline (PBS) against eight bacteria and one yeast. The results of the test were compared with ampicillin. It was determined that CCDOP1, CCDOP3 and DOP have significant antibacterial and antifungal activity. These three chemicals revealed strong antibacterial activity against the E. coli and S. aureus strains used in the study. S. aureus was the most sensitive strain against dopamine hydrochloride and E. coli was the most sensitive bacteria against CCDOP1.

Synthesis of Star-Shaped Macromolecular Schiff Base Complexes Having Melamine Cores and Their Magnetic and Thermal Behaviors

Abstract We aim to study magnetic and thermal behaviors of some melamine cored macromolecular Schiff base complexes. In this context, tripodal ligands were synthesized by reacting melamine with 4-carboxybenzaldehyde or 4-hydroxybenzaldehyde. Then, 16 new trinuclear Fe(III), Cr(III), Mn(III), and Al(III) complexes were synthesized by reacting the ligands [tris-(4-carboxybenzimino)-1,3,5-triazine) or tris-(4-hydroxybenzimino)-1,3,5-triazine)] with pentadentate Schiff bases N,N′-bis(1-hydroxy-2-benzyliden)-1,7-diamino-4-azaheptane or N,N′-bis(salicylidene)pyridine-2,6-diamine. Later, ligands and complexes were characterized by means of elemental analysis, infrared spectroscopy, 1H NMR, liquid chromatography–mass spectrometry, thermal analyses, and magnetic susceptibility measurements. Finally, metal ratios of the prepared complexes were determined by using atomic adsorption spectrometry. The complexes were also characterized as distorted octahedral high-spin d 3 (S = 3 × 1/2) Cr(III), high-spin d 5 (S = 5 × 1/2) Fe(III), low-spin d 4 (S = 2 × 1/2) Mn(III), and diamagnetic Al(III) bridged by ‒OH group of COO− or OH group of phenol. GRAPHICAL ABSTRACT

Synthesis and characterization of new vic-dioximes and their metal complexes with Cu(II), Ni(II), and Co(II) salts

Abstract4-Acetyldiphenyl sulfide and 4,4′-diacetyldiphenyl sulfide were synthesized from diphenyl sulfide and acetyl chloride in the presence of AlCl3 as catalyst in the Friedel-Crafts reaction. Subsequently, the ketooxime and glyoxime derivatives were also prepared. The metal complexes of the glyoximes, such as copper, nickel, and cobalt complexes were prepared. The BF2+ capped Ni(II) mononuclear complex of 4-thiophenoxyphenylglyoxime was prepared. The structures of these ligands were identified by FT-IR, 1H NMR, and 13C NMR spectral data and elemental analysis. The structures of the complexes were identified by FT-IR, elemental analysis, and magnetic measurements.

Synthesis and Characterization of Some vic-Dioxime and its Mononuclear Complexes

In this study, acetophenone is used as a basis substance. ω-Isonitrosoacetophenone has been synthesized from nitrosyl with amyl nitrite of acetophenone in the presence of sodium ethoxide. Subsequently, anti-phenylglyoxime has been prepared by reacting ω-isonitrosoacetophenone with hydroxylamine and sodium acetate in a ethanolic media. Chlorophenylglyoxime has been obtained from reaction with chlorine gases. Then, three aminophenylglyoxime (ligands) have been prepared by the reaction of chlorophenylglyoxime and the corresponding amines. The Ni(II), Co(II), and Cu(II) complexes with BF2+-bridge of anilinophenylglyoxime and 2,4-dimethylanilinophenylglyoxime were prepared. Then polymeric metal complexes with BF2+-bridge of dopamiophenylglyoxime were prepared. Their structures were identified by FT-IR, 1H NMR, and ICP-AES spectral data, elemental analysis and magnetic measurements.