Hava Ozay

Spectroscopic study and structure of (E)-2-[(2-chlorobenzylimino)methyl]methoxyphenol.

(E)-2-[(2-chlorobenzylimino)methyl]methoxyphenol has been synthesized from the reaction of 2-hydroxy-3-methoxy-1-benzaldehyde(o-vanillin) with 2-chlorobenzylamine. The title compound has been characterized by using elemental analysis, FT-IR, (1)H NMR, (13)C NMR and UV-vis spectroscopic techniques. The crystal structure of the title compound has also been examined cyrstallographically. It crystallizes in the orthorhombic space group Pbca with unit cell parameters: a = 7.208(1) A, b = 13.726(2) A, c = 27.858(4) A, V = 2756.0(1) A(3), D(c) = 1.18 g cm(-3) and Z = 8. The crystal structure was solved by direct methods and refined by full-matrix least squares to a find R = 0.046 for 2773 observed reflections.

Utilization of Environmentally Benign Hydrogels and Their Networks as Reactor Media in the Catalytic Reduction of Nitrophenols

Iron particles were synthesized inside poly(2-acrylamido-2-methyl-1-propansulfonic acid) (p(AMPS)) and used as a catalyst in the reduction of nitro benzene and 4-nitrophenol to aniline and 4-aminophenol, respectively, in acidic medium. It was demonstrated that hydrogel networks can be used effectively as catalysis media in the reduction of some organic toxic materials. The results verified that iron particles containing p(AMPS) hydrogel networks yield faster conversion rates. Additionally, iron nanoparticles containing p(AMPS) hydrogel networks could catalyze the reaction, giving 32% yield without any added cocatalyst, providing self cocatalyst mission.

Copper and cobalt complexes of octadentate azamacrocycles: spectrophotometric titration, stopped-flow kinetics and crystallographic study.

Details of complex formation kinetics are reported for tetrakis(2-hydroxyethyl) substituted cyclen (L(1)) and cyclam (L(2)) with Cu(II) and Co(II). Stopped-flow kinetics and spectroscopic titration methods were employed for the activation parameters and stability constants, respectively. X-ray studies revealed that the pendant 2-hydroxyethyl groups are not equivalent: two are folded over the macrocycle and maintained by intramolecular hydrogen bonds while the others are extended and pointed away from the macrocyclic cavity. Complex formation kinetics and spectroscopic titration were performed in aqueous acidic buffer solutions. Thermodynamic and kinetic parameters revealed that the ring size of the macrocycles plays an extremely important role for each metal ion studied. Stopped-flow kinetic measurements explained the mechanism of the complex formation process of both Cu(II) and Co(II) which proceed in outer-sphere interactions with ligands. There are two steps in the complex formation of the system studied. The initial step is a second order reaction between the metal ion and macrocycle with a second order rate constant.

Synthesis, Characterization, and Naked-Eye Sensor Application of Fully Substituted Urea-Based Cyclotriphosphazene Compound

GRAPHICAL ABSTRACT Abstract A novel sensor with a hexacenter containing nitrophenylurea groups on a cyclotriphosphazene core was synthesized by “click” reaction of N-propargyl-substituted urea with a hexaazide-substituted cyclotriphosphazene compound. It was characterized by spectroscopic techniques such as Fourier transform infrared spectroscopy, nuclear magnetic resonance, and mass spectroscopy. This compound was used for naked-eye and spectrophotometric detection of F− anions. The optical sensor properties of compound were investigated using ultraviolet–visible spectroscopy.

Spectroscopic and structural properties of N-(acetamide) morpholinium bromide.

A new crystal of N-(acetamide) morpholinium (NAM) bromide has been prepared in methanol at room temperature and characterized by single crystal X-ray analysis, elemental analysis, GS-MS, FTIR, NMR((1)H,(13)C, DEPTH and HETCOR). The N-(acetamide) morpholinium crystallizes in the orthorhombic crystal system, Pnma with unit cell a=12.798(9) Å, b=7.222(5) Å, c=9.244(5) Å, β=90.00, V=854.4(9) Å(3), Z=4. The X-ray structure determination revealed that there are strong inner and intermolecular hydrogen bonds in the crystal.

Spectroscopic studies and crystal structure of (E)-N′-(2-hydroxy-3-methoxybenzylidene)isonicotinohydrazide

The structure of compound has also been examined cyrstallographically. It crystallizes in the monoclinic space group P21/c with a = 7.673(1), b = 16.251(2), c = 10.874(1) Å, β = 110.42(1)°, V = 1270.7(3) Å3, Dx = 1.418 g cm−3, R1 = 0.0349 and wR2 = 0.0935 [I > 2σ(I)], respectively. The title compound has been synthesized from the reaction of isonicotinohydrazide with 2-hydroxy-3-methoxybenzaldehyde. It has been characterized by using elemental analysis, MS, IR, 1H NMR, 13C NMR and UV-Visible spectroscopic techniques.

The stabilities and formation kinetics of some macrocycles with copper(II): crystal structures of some pendant arm macrocycles

Kinetics of complex formation and stability constants of tetra-(2-hydroxpropyl) substituted cyclam (L3) and cyclen (L4) with copper(II) have been studied in aqueous solution at room temperature. These data are compared to the corresponding parent compounds (cyclam L1 and cyclen L2) in an attempt to define the effect of pendant arm upon kinetics and stability constants of the complexes. The kinetics were observed by stopped-flow measurements followed at multiwavelengths. These ligands were chosen to furnish information concerning effect of pendant groups and cavity size on the kinetics and stability of the complexes. Stopped-flow and spectrophotometric titration techniques were used for evaluation of the kinetics and stability constants, respectively. The apparent rate constants increase as CuL3 > CuL4 > CuL1 > CuL2. Activation parameters and stability constants of the complexes were estimated. The effect of cavity size on the rate of reaction can be observed in CuL3 > CuL4 and CuL1 > CuL2 and the effect of pendant groups in CuL3 > CuL1 and CuL4 > CuL2. Mechanism of the complex formation reaction is proposed. The enhanced stability of the copper(II) complexes formed with L1 and L2 macrocyclic ligands is compared to those formed with analogous pendant arm species.

Spectroscopic Studies and Crystal Structure of Four-Coordinate Manganese(II) Chloride Complex

High-spin new, manganese-(II) L2MnCl2, complex has been synthesized and its structure was elucidated by using elemental analysis, FT-IR, DTA-TG, 1H-NMR, 13C-NMR, and UV-Visible spectroscopic techniques. The structure of the compound has also been examined crystallographically. The title compound crystallizes in the triclinic space group P-1, with unit cell parameters: a = 11.354(1), b = 11.868(1), c = 12.080(1) Å, V = 1548.9(1) Å3, Dx = 1.270 g.cm−3, and Z = 2, respectively. The Mn atom was tetra-coordinated to form a distorted tetrahedral geometry by two oxygen atoms of L2 and two chloride atoms of MnCl2.4H2O in the complex.

Synthesis, complex formation kinetics and thermodynamic study of some acyclic polyamine and N2O2 ligands with copper(II)

The polydentate ligands, 3-(2-aminocyclohexylamino)-2-(2-aminocyclohexyl aminomethyl) propionic acid (L1 ), 4,7,10-triazatridecanedinitrile trihydrochloride (L2 ), and 2,2′-(ethane-1,2-diyl) bis(methylazanediyl) diethanol (L3 ) were prepared and their structures investigated by FT-IR, NMR, and MS. The kinetics of complex formation between Cu(II) and L1, L2, and L3 were investigated in acidic aqueous solutions using the stopped-flow method. The stability constants of the complexes were determined by spectrophotometric titration (T = 293 K, μ = 0.1 mol L−1 NaClO4), using a diode array UV-Vis spectrophotometer equipped with peristaltic pump and pH meter. The stability constants for the complexes were CuL1 > CuL2 > CuL3. Activation enthalpies (ΔH#) of these complexes were 55 kJ mol−1 for CuL1, 61 kJ mol−1 for CuL2, and 36 kJ mol−1 for CuL3, respectively.

Synthesis, structural characterization, and anion interactions of new triazole-linked urea derivative fully substituted cyclotriphosphazene compounds

GRAPHICAL ABSTRACT ABSTRACT Three novel fully substituted urea derivative cyclotriphosphazene compounds 5–7 were synthesized by alkyne-azide 1,3-dipolar cycloaddition reaction of propargyl substituted ureas 2–4 with hexaazide substituted cyclotriphosphazene 1 in the presence of Cu(I) catalyst. All compounds were characterized with spectroscopic techniques such as FT-IR, 1H, 13C, and 31P nuclear magnetic resonance and mass spectroscopy. Also, the usefulness of compounds 5–7 as anion carriers was investigated by 1H NMR spectroscopy. For this purpose, 1H NMR spectra of compounds 5–7 were recorded in the presence of tetrabutylammonium fluoride in DMSO-d6. It was determined, that the urea protons in the compounds interact with fluoride.