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The multivariate calibration methods-moving window selection partial least squares regression (MWPLSR) and net analyte signal (NAS)-were employed for simultaneous determination of a mixture of C.I. Disperse Blue 183, C.I. Disperse Blue 79. C.I. Disperse Red 82, C.I. Disperse Red 65, C.I. Disperse Yellow 211 and C.I. Disperse Orange 25 by UV-vis spectrophotometry. The absorption spectra of the six disperse dyes were recorded between 320 and 680 nm. A modified changeable size moving window partial least squares (CSMWPLS) and searching combination moving window partial least squares (SCM WPLS) were proposed to search for an optimized spectral interval and an optimized combination of spectral regions from informative regions obtained by MWPLSR. Different wavelength regions were selected by taking into account different spectral parameters including the starting wavelength, the ending wavelength and wavelength interval. It was found that wavelength selection improved the performance of the corresponding net analyte signal-partial least squares (NAS-PLS) model, in terms of root mean square error (RMSE), compared with the results obtained using whole spectra or direct combination of informative regions for each dye. The importance of calibration design was also investigated by calculating the prediction and validation errors. The influence of using independent validation sets were emphasized. The proposed calibration method gave better results in combination and informative spectral regions for determination of the six disperse dyes without prior separation.

Two new water-soluble copper(II) complexes, [Cu(dmphen)(2)(NO3)]NO3 (1), [Cu(dmphen)(tyr)(H2O)] NO3 center dot H2O (2) and the diquartemary salt of dmphen (dmphen = 4,7-dimethyl-1,10-phenanthroline and tyr = L-tyrosine), have been synthesized and characterized by elemental analysis, H-1 NMR, C-13 NMR and IR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. The CT-DNA binding properties of these compounds have been investigated by absorption, emission spectroscopy and thermal denaturation measurements. The supercoiled pBR322 plasmid DNA cleavage activity of these compounds has been explored by agarose gel electrophoresis. The cytotoxicity of these compounds against MCF-7, Caco-2, A549 cancer cells and BEAS-2B healthy cells was also studied by the XTT method. Complexes 1 and 2 exhibit significant cytotoxicity, with lower IC50 values than those of cisplatin.

A series of new mercury(II) azine Schiff base complexes have been synthesized and characterized from the initial use of phenyl-2-pyridyl ketone azine in Hg-II chemistry. The synthetic/crystallization technique utilized involved the use of a branched tube, where temperature differential allowed for the slow crystallization of the products. The synthesized compounds are the mononuclear [Hg(L)Cl-2] (1), [Hg(L)Br-2] (2), [Hg(L)(NO2)(2)] (3), and the dinuclear [Hg-2(mu-L)(SCN)(4)] (4) coordination compounds, as well as a 1D coordination polymer [Hg(L)(mu-I)(2)HgI2](n) (5) (L = phenyl-2-pyridyl ketone azine). From the X-ray data, it is evident that this versatile ligand functions as a bi- or tridentate chelate, and is also able to bridge two H-II centers. The crystal structures of 1 and 2 are similar, both containing two crystallographically independent Hg-II molecules, one tetrahedrally coordinated and one exhibiting trigonal bipyramidal geometry. The heptacoordinated Hg-II center in 3 adopts a distorted capped trigonal prismatic coordination sphere, while in the dinuclear complex 4, the metal ions are bridged via the bis(bidentate) L and each center is also bound to two S-bonded thiocyanate units. The one-dimensional coordination polymer in 5 consists of a tetrahedral HgI4 and a trigonal bipyramidal HgN3I2 chromophore unit, bridged by mu-I- bridges. The thermal stability of the crystal lattice in 1-5 follows the pattern 3 > 1 > 2 > 5 > 4, as studied by TG/DTA, while the TG data of 1,2, and 5 are similar, but different than the respective ones for 3 and 4, between which important similarities are observed. In the solid state, the ligand and compounds 1-5 exhibit intraligand pi -> pi* fluorescence at room temperature. University of Tabriz Research Council Council of Scientific & Industrial Research (CSIR) - India Research Corporation for Science Advancement

The effects of ultrasonic-assisted extraction factors for the main phenolic compound (quercetin) from Hypericum perforatum L. were optimized using the Box-Behnken design (BBD) combined with response surface methodology. The BBD was employed to evaluate the effects of extraction temperature (30-70 degrees C), extraction time (20-80min), methanol concentration (20-80%, v/v), and HCl concentration (0.8-2.0M) on the content of one of the major phenolic compounds of quercetin. The extracts were analyzed by high performance liquid chromatography (HPLC). The major phenolic compounds of H. perforatum were isolated and the antioxidant capacity and total phenol content were determined in crude extract and fractions. The optimum conditions were determined as extraction temperature 67 degrees C, extraction time 67min, methanol concentration 77% (v/v), and HCl concentration 1.2M. The predicted content of quercetin was 10.81mg/g dried plant under the optimal conditions and the subsequent verification experiment with 11.09mg/g dried plant confirmed the validity of the predicted model. The isolated compounds were identified as quercetin, cyanidin, protocatechuic acid, and kaempferol.

The aim of the present study is to investigate DNA binding interactions of two highly cytotoxic palladium(II) saccharinate (sac) complexes with 2,2':6',2 ''-terpyridine (terpy), [Pd(sac)(terpy)](sac)center dot 4H(2)O (1) and [PdCl (terpy)](sac)center dot 2H(2)O (2). UV-Vis spectroscopy, fluorescence spectroscopy, thermal denaturation, viscosity, and gel electrophoresis measurements were employed to study binding properties of the two complexes with Fish Sperm (FS) DNA. The interaction of the palladium(II) complexes with FS-DNA was monitored by hypochromism in the UV-Vis spectra. The binding constants (K-b) obtained from absorption titrations were estimated to be 1.0 (+/- 0.05) x 10(5) M-1 for 1 and 2.0 (+/- 0.22) x 10(5) M-1 for 2. Competitive binding studies with ethidium bromide have shown that both complexes strongly bind to FS-DNA, and the apparent binding constant (K-app) calculated from emission studies was 2.0 x 10(6) M-1 for each complex. Fluorescence Scatchard plots demonstrated that the palladium(II) complexes act as dual-function metallointercalators and bind to FS-DNA by both intercalation and coordination. On addition of the two complexes, significant increases in both viscosity and melting temperature of FS-DNA solutions further support the binding mode of these complexes. Gel electrophoresis assay demonstrates that both complexes efficiently cleavage the supercoiled plasmid 8454: pCMV-VSV-G DNA to its open circular form.

WOS: 000324103300007, The influence of poly(ethylene glycol) (PEG) and synthesis temperature in the synthesis of SBA-15-SO3H was investigated to evaluate the catalytic activity in the esterification of propionic acid with methanol. The catalysts were characterized by means of surface and structure analyses; X-ray diffraction, FT-IR, scanning electron microscopy, Thermo-gravimetric and N-2 adsorption/desorption techniques. It was found that, by the addition of PEG, the surface area and porosity of SBA-15-SO3H increased, while the structure and size of mesopores remained unchanged. Nitrogen sorption measurements indicate that PEG introduces additional pores into the pore walls of SBA-15-SO3H. Thus, a simple way of improving the porosity of mesoporous SBA-15-SO3H was presented that could enhance transport of substrates through the porous system and allow the generation of stable mesoporous replicas, important for catalytic applications and also beneficial for replication and nanocasting purposes., Commission of Scientific Research Projects of Uludag University [UAP(F)-2011/69], This work was supported by The Commission of Scientific Research Projects of Uludag University, Project number: UAP(F)-2011/69.

Four trans-palladium(II)- and trans-platinum(II)-chlorido complexes, trans-[PdCl2(2-hmpy)(2)] (1), trans-[PtCl2(2-hmpy)(2)] (2), trans-[Pdcl(2)(2-hepy)(2)] (3) and trans-[PtCl2(2-hepy)(2)] (4) (2-hmpy = 2-(hydroxymethyl)pyridine and 2-hepy = 2-(2-hydroxyethyl)pyridine), have been synthesized and characterized by elemental analysis, IR, NMR, and X-ray diffraction. The binding properties of these complexes with fish sperm DNA (FS-DNA) were investigated by UV titration, viscosity, thermal denaturation and electrophoresis measurements. The complexes can bind to FS-DNA and complex 4 exhibits the highest binding constant. Gel electrophoresis assay demonstrates that all the complexes can cleave the pCMV-beta gal plasmid DNA to a different degree. The cytotoxic activities of the complexes were tested against four different cancer cell lines. In general, the platinum(II) complexes are more effective than the isostructural palladium(II) complexes. Complex 4 shows high anticancer activity, compared to transplatin, cisplatin, carboplatin and oxaliplatin. (C) 2012 Elsevier Masson SAS. All rights reserved.

In this study, the composition and stability constants of a mixed ligand complex of Sc(III), Y(III) and La(III) ion by using NTA (H3B) (Nitrilotriacetic acid) and HEDTA (H3B) (N-(2-hydroxyethyl)ethylenedinitrilotriacetic acid) as a primary ligand and 2,3-DHBA (H(3)A) (2,3-dihydroxybenzoic acid) as secondary ligand have been determined by using a potentiometric method and the BEST computer programme at 25 degrees C, in a 0.1 M NaCl ionic medium. The complex stability was found to follow the trend Sc(III) > Y(III) > La(III) based on the ionic radius of the metal ions.

The magnetic-poly(divinylbenzene-4-vinylpyridine) [m-poly(DVB-4VP)] microbeads (average diameter: 180–212 μm) were synthesized by copolymerizing of divinylbenzene (DVB) with 4-vinylpyridine (4VP) and by mixing this copolymer with Fe 3 O 4 nanoparticles. The resultant material was characterized by N 2 adsorption/desorption, ESR, elemental analysis, scanning electron microscope (SEM) and swelling studies. After functionalized with sulfonic acid, m-poly(DVB-4VP-SO 3 H) was characterized by FT-IR and TGA analysis. The results showed that both of Fe 3 O 4 and –SO 3 H are bonded to the polymer successfully. N 2 adsorption/desorption isotherms of synthesized samples had the hysteresis behaviour associated with mesoporous materials (pore diameter: 3.73 nm). Sulfonic acid functionalized mesoporous m-poly(DVB-4VP-SO 3 H) has been demonstrated to have higher reactivity than commercially available solid acid catalysts for the conversion of propionic acid to methyl ester. The apparent activation energy was found to be 38.5 kJ mol −1 for m-poly(DVB-4VP-20%SO 3 H). The catalyst showed negligible loss of activity after four repetitive cycles.

The synthesis of two new calixarene derivatives 4 and 5, functionalized at the lower rim with 4-amino-1-benzylpiperidine to give diamide and diamine derivatives of p-tert-butylcalix[4]arene, is described. They were obtained by the reaction of both the diester derivative of p-tert-butylcalix[4]arene (2) and the dialkyl bromide derivative of p-tert-butylcalix[4]arene (3) with 4-amino-1-benzylpiperidine. The (1)H NMR spectra of calixarene derivatives show that 4 and 5 exist in the cone conformation. Moreover, these diamide and diamine derivatives of p-tert-butylcalix[4]arene (4 and 5) have been immobilized onto 13-(2,3-epoxypropoxy)-Propyl]-trimethoxysilane-modified Fe(3)O(4) magnetite nanoparticles to obtain calixarene-based magnetic nanoparticles M-DADBP-Calix (6) and M-DABP-Calix (7). The calix[4]arene immobilized materials were characterized by a combination of Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Thermogravimetric Analyses (TGA) and elemental analysis. Additionally, the studies regarding the removal of As(V)/Cr(VI) ions as well as U(VI) ion from aqueous solutions were also carried out by using these compounds in liquid liquid/solid liquid extraction experiments. (C) 2011 Elsevier Ltd. All rights reserved. Selçuk Üniversitesi

Lipase enzyme from Aspergillus oryzae (EC 3.1.1.3) was immobilized onto a micro porous polymeric matrix which contains aldehyde functional groups and methyl esters of long chain fatty acids (biodiesel) were synthesized by transesterification of crude canola oil using immobilized lipase. Micro porous polymeric matrix was synthesized from styrene divinylbenzene (STY-DVB) copolymers by using high internal phase emulsion technique and two different lipases, Lipozyme TL-100L (R) and Novozym 388 (R), were used for immobilization by both physical adsorption and covalent attachment. Biodiesel production was carried out with semi-continuous operation. Methanol was added into the reactor by three successive additions of 1:4 M equivalent of methanol to avoid enzyme inhibition. The transesterification reaction conditions were as follows: oil/alcohol molar ratio 1:4; temperature 40 degrees C and total reaction time 6 h. Lipozyme TL-100L (R) lipase provided the highest yield of fatty acid methyl esters as 92%. Operational stability was determined with immobilized lipase and it indicated that a small enzyme deactivation occurred after used repeatedly for 10 consecutive batches with each of 24 h. Since the process is yet effective and enzyme does not leak out from the polymer, the method can be proposed for industrial applications. (C) 2010 Elsevier Ltd. All rights reserved.

A modified two-step seeded polymerization was used for the preparation of porous mono-sized microspheres of poly(ethylene glycol dimethacrylate-co-1-vinylimidazole) [poly(EGDMA-co-VIM)] of 7 mu m in size. The specific surface area and the EGDMA/VIM molar ratio of the microspheres were determined as 64.5 m(2)/g and 1.5:1.0 mol/mol, respectively. The adsorption of Pb(II) ions from aqueous solution onto the porous mono-sized poly(EGDMA-co-VIM) microspheres was examined. The maximum adsorption capacities of the microspheres towards Pb(II) ions were determined as 21.74, 30.52, 49.23 and 56.48 mg/g at 293 K, 303 K, 318 K and 338 K, respectively. The dynamic and equilibrium adsorption behaviours of the system were adequately described by the pseudo-second-order kinetic model and the Langmuir isotherm, respectively. The apparent activation energy was determined as 6.212 kJ/mol, which is characteristic of a chemically controlled reaction. The values of E-fe obtained from the Dubinin-Radushkevich equation in the non-linear form were 9.153 kJ/mol at 293 K, 10.34 kJ/mol at 303 K, 10.18 kJ/mol at 318 K and 10.91 kJ/mol at 333 K, thereby indicating that the adsorption of Pb(II) ions onto the porous mono-sized poly(EGDMA-co-VIM) microspheres occurred via a chemical process at all the temperatures studied. Various thermodynamic parameters, such as the Gibbs' free energy change (Delta G(0)), the standard enthalpy change (Delta H-0) and the standard entropy change (Delta S-0) were also determined. The thermodynamic parameters obtained indicated that the adsorption process was endothermic in nature. These results demonstrate that the material studied could be used as a purifier for the removal of Pb(II) ions from water and wastewater.

Airborne particulate matter (PM) and associated metals were measured in a district of an industrial city in Western Turkey. We compared PM concentrations in Bursa, Turkey (Nilufer district) with international air quality standards. Turkish legislature adopted the EC Air Quality Framework in 2008, and compliance is required in the medium term. State-of-the-art reference methods were used for all measurements. A Partisol sampler measured urban background PM2.5 and PM10 between May 2007 and April 2008, and PM2.5 samples were later analysed for selected metals using ICP-MS. Average PM2.5 and PM10 mass concentrations over the year were 53 and 83 mu g/m(3), respectively. The annual mean PM2.5:PM10 ratio in Bursa was 0.64. PM2.5 and PM10 were highly correlated at the site (R=0.91 overall), especially in winter. In the cold seasons, the coarse and fine fractions were strongly correlated R=0.67 (p

The synthesis of single wall nanotubes (SWNT)/poly(vinyl)triazole (PVTri) composites by in situ emulsion polymerization method and its chemical and physical properties were investigated throughout this work. The surface modification of the SWNT by nitric acid treatment and air oxidation has improved the dispersion of the SWNT in the PVTri matrix. The SWNT/PVTri composite is obtained by covalent bonding of the carboxyl terminated SWNTs to PVTri. The effect of covalent bond formation between PVTri and SWNT on the thermal and electrical properties of the composite is also studied. The spectroscopic, thermal, and microscopic analysis has confirmed the structure, homogeneity, and the morphology of surface functionalized SWNT and SWNT/PVTri composites. SWNT/PVTri composites showed enhanced chemical stability in many common solvents and high electrical conductivity.

The EI mass spectra of 3,4-disubstituted-1,2,4-oxadiazin-5-ones 1-6 and -thiones 7,8 and 3,5-disubstituted 1,2,4-oxadiazin-6-ones 9,10 were recorded and their fragmentation pathways solved and compared with each other. The fragmentation routes of 5-ones and 5-thiones do not differ very much from each other but compounds 9 and 10 behave differently as could be expected based on their lactone type structures. Only compounds 4-6 exhibit a loss of CO and compound 7 a loss of NO. The loss of a benzyl group dominates the behaviour of compounds 1 and 2 which showed only few additional fragmentations. Some earlier data on some 3,4-disubstituted-1,2,4-diazin-5-ones 11-13 and -thiones 14,15 have been reanalyzed and discussed in further detail.

Poly(ethylene glycol dimethacrylate-1-vinyl-1,2,4-triazole) [poly(EGDMA-VTAZ)] beads (average diameter = 150–200 μm) were prepared by copolymerizing ethylene glycol dimethacrylate (EGDMA) with 1-vinyl-1,2,4-triazole (VTAZ). Poly(EGDMA-VTAZ) beads were characterized by swelling studies and scanning electron microscope (SEM). The adsorption of Cr(VI) from solutions was carried at different contact times, Cr(VI) concentrations, pH, and temperatures. High adsorption rates were achieved in about 240 min. The amount of Cr(VI) adsorbed increased with increasing concentration and decreasing pH and temperature. The intraparticle diffusion rate constants at various temperatures were calculated. Adsorption isotherms of Cr(VI) onto poly(EGDMA-VTAZ) have been determined and correlated with common isotherm equations such as Langmuir and Freundlich isotherm models. The Langmuir isotherm model appeared to fit the isotherm data better than the Freundlich isotherm model. The pseudo first-order kinetic model was used to describe the kinetic data. The study of temperature effect was quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy, and entropy changes. The dimensionless separation factor (RL) showed that the adsorption of metal ions onto poly(EGDMA-VTAZ) was favorable. It was seen that values of distribution coefficient (KD) decreasing with Cr(VI) concentration in solution at equilibrium (Ce) indicated that the occupation of activate surface sites of adsorbent increased with Cr(VI). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

The one-pot azidation and benzoylation of a mixture of cis (-)-menthyl phenylglycidates provide quantitatively the corresponding (2R,3S)-, and (2S,3R)-3-azido-1-((1R,2S,5R)-2-isopropyl-5-methylcyclohexyloxy) -1-oxo-3-phenylpropan-2-yl benzoate. Enantiopure (2R,3S)-3-azido-1-((1R,2S,5R)- 2-isopropyl-5-methylcyclohexyloxy)-1-oxo-3-phenylpropan-2-yl benzoate crystallize from MeOH at room temperature in high yields. The reduction of the latter with Zn-TMSCl produces (-)-menthyl 3-benzamido-3-phenyl-2- (trimethylsilyloxy)propanoate which upon simultanious desilylation and hydrolysis provide the taxol side chain N-benzoyl-(2R,3S)-3-phenylisoserine.

Interactions of certain amino acids with some metal ions have significant consequences in biological systems. Metal ions can act as co-factors in the regulation of enzymatic reactions. Interactions of metal ions with amino acid side chains or with different organic complexes is also essential for many biological events. In this study, the stability constants of 1 : 1 : 1 ternary complexes of Cu(II) with 1,10-phenanthroline (Phen) as the primary ligand, and 2,2'-bipyridyl (Bpy) and some selected alpha-amino acids [(glycine (Gly), leucine (Leu), glutamine (Gln)] as secondary ligands, were identified in I=0.1 M ionic medium at t=(25+/-0.1) degrees C in aqueous solutions, by potentiometry. The protonation constants of the free ligands and the stability constants of the binary and ternary systems were also determined under the same experimental conditions. The protonation constants of all of the ligands and the stability constants of the formed complexes were evaluated by using the BEST computer program. The stabilities of the ternary complexes have been quantitatively compared with those of the corresponding binary complexes in terms of the some parameters. The concentration distributions of the complexes in solution were also evaluated. Species distributions as a function of pH reveal that the MAB ternary complexes predominate over a pH range, where M=Cu(II); A=Phen; B=Bpy, Gly, Leu and Gln.

Magnetic vinylphenyl boronic acid microparticles, poly(ethylene glycol dimethacrylate(EG)-vinylphenyl boronic acid(VPBA)) [m-poly(EG-VPBA)], produced by suspension polymerization and characterized, was found to be an efficient solid polymer for Cr(VI) adsorption. The m-poly(EG-VPBA) microparticles were prepared by copolymerizing of ethylene glycol dimethylacrylate (EG) with 4-vinyl phenyl boronic acid (VPBA). The m-poly(EG-VPBA) microparticles were characterized by N-2 adsorption/desorption isotherms, electron spin resonance (ESR), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), elemental analysis, scanning electron microscope (SEM) and swelling studies. The m-poly(EG-VPBA) microparticles were used at adsorbent/Cr(VI) ion ratios. The influence of pH, Cr(VI) initial concentration, temperature of the removal process was investigated. The maximum removal of Cr(VI) was observed at pH 2. Langmuir isotherm and Dubinin-Radushkvich isotherm were found to better fit the experiment data rather than Fruendlich isotherm. The kinetics of the adsorption process of Cr(VI) on the m-poly(EG-VPBA) microparticles were investigated using the pseudo first-order, pseudo-second-order, Ritch-second-order and intraparticle diffusion models, results showed that the pseudo-second order equation model provided the best correlation with the experimental results. The thermodynamic parameters (free energy change, Delta G(0) enthalpy change, Delta H-0; and entropy change, Delta S-0) for the adsorption have been evaluated.

The article presents the results of optimization of operation parameters, investigation of analytical characteristics and the abilities of a graphite filter-furnace (FF) atomizer for the direct electrothermal atomic absorption spectroscopy (ET AAS) determination of trace amounts of Mn, As, Pb, Cu, Cd and Zn in some vegetable oils and fats. The effect of pyrolysis and atomization temperatures of the graphite FF atomizer on atomic absorbance values of the listed elements at their evaporation from some organic solutions in the presence of a Pd-Mg chemical modifier (CM) was investigated. For the ET AAS determination of As, Pb, Cd and Zn with Pd-Mg CM, the temperature of the graphite FF atomizer for the pyrolysis step can be raised by 250-350 degrees C. This mode allows to eliminate the background absorption, to increase the sensitivity of the elements to be analyzed and to enhance the total content of vegetable oils or fats in organic solutions up to 0.5 g mL(-1). The obtained limits of quantification for Mn, As, Pb, Cu, Cd and Zn were 0.002, 0.004, 0.004, 0.002, 0.0008, 0.0004 mg kg(-1), respectively. The relative standard deviation (RSD) varied between similar to 3 and 8% and the time of one element determination did not exceed similar to 3-5 min. The reliability of the proposed method was checked using the reference method. A paired Student's t-test showed no significant difference between the results obtained by both methods on a 95% confidence level.

Binary and ternary water soluble copper(II) complexes - [Cu(nphen)(2)(H2O)](NO3)(2)center dot H2O (1), [Cu(phen)(2)(H2O)](NO3)(2) (2), [Cu(nphen)(L-tyr)(H2O)]NO3 center dot 2H(2)O (3), [Cu(Phen)(tyr)(H2O)] NO3 center dot 2H(2)O (4) - and diquarternary salts of nphen and phen (nphen = 5-nitro-1,10-phenanthroline, phen = 1,10-phenanthroline and tyr = L-tyrosine) have been synthesized and characterized by CHN analysis, H-1 NMR, C-13 NMR and IR spectroscopy, thermal analysis and single crystal X-ray diffraction techniques. The CT-DNA binding properties of these compounds have been investigated by thermal denaturation measurements, absorption and emission spectroscopy. The supercoiled pUC19 plasmid DNA cleavage activity of these compounds has been explored by agarose gel electrophoresis. The cytotoxicity of these compounds against MCF-7, Caco-2, A549 cancer cells and BEAS-2B healthy cells was also studied by using XTT method. The complexes 1-4 exhibit significant high cytotoxicity with low IC50 values in compared with cisplatin. The effect of the substituents of phen and coordinated amino acid in the above complexes are presented and discussed.

This paper introduces a fractionation scheme using water, acetone, chloroform, diethyl ether, ethanol, n-hexane, and methanol as extractants for the determination of manganese in spinach samples by inductively coupled plasma-mass spectrometry (ICP-MS). Simulated gastric and intestinal digestions as well as n-octanol extraction and activated carbon adsorption were performed for the bioavailability assessments. Comparative studies of the various extraction treatments were evaluated for confirmation analysis. The total elemental concentrations were determined after digesting the samples in a microwave digestion system. The method validation parameters were defined in terms of the detection limits, accuracy, and precision. Additional validation was performed by comparing the ICP-MS method with atomic absorption spectrometry. The limits of detection and quantification were 0.046 and 0.154 mg kg(-1), respectively. Additionally, the repeatability and reproducibility, calculated from the relative standard deviation (%RSD), were 2.4% and 3.7%, respectively.

A new ligand, 2−(p−tolyl)−1,2,3,4−tetrahydroquinazoline−2 −carbaldehyde oxime, was synthesized from a condensation reaction of oxo−p−tolyl−acetaldehyde oxime with 2−aminobenzyl- amine and then amine−imine−oxime complexes of this compound that formed with Co(III) and Ni(II) ions were obtained. All structures were characterized by spectral methods, elemental analysis, magnetic susceptibility, molar conductivity, and thermal analyses. The results that were obtained show that the cyclic ligand, HL, undergoes a ring−opening reaction upon complexation with metal ions. The Co(III) and Ni(II) complexes have a metal−ligand ratio of 1:2 and the imine ligand coordinates through the amine, imine, and oxime groups nitrogen atoms with metal ions.

One of the major causes of soil degradation throughout the world is water erosion. Anionic polyacrylamide (PAM) application to soils is an effective soil conservation practice for reducing runoff and soil losses caused by erosion. It also increases the infiltration rate of soils. The objective of this study was conducted to determine effects of different application rates of PAM (0 (control), 1.667, 3.333 and 5.000 kg.ha -1 ) on infiltration rate, runoff and soil losses. Polyacrylamide was sprayed on the surface of the experimental soils with different textures. The PAM treated soils were introduced to simulated rainfall at 61 mm/h intensity for an hour. The results indicated that, PAM applications significantly reduced surface runoff and soil losses, but increased infiltration rates. The effectiveness of PAM was higher in clay and clay loam soils than that of sandy clay loam soil. The most effective applications rates of PAM on reducing surface runoff and soil losses and increasing infiltration rates were found to be 3.333 and 5.000 kg.ha -1 . By considering the price and application cost of PAM, It was suggested that 3.333 kg.ha -1 PAM is the most suitable application rate. As compared with the control, it was obtained that PAM application with a rate of 3.333 kg.ha -1 reduced surface runoff and soil losses by 23.1 and 18.5%, respectively and increased infiltration rate by 24%. Key words : Polyacrylamide (PAM), soil erosion, soil loss, runoff, infiltration rate, simulated rainfall.

In this study, decolorization of three disperse dyes by ozonation was evaluated. The dyes assessed represent low (CI Disperse Blue 56), medium (CI Disperse Blue 60) and high (CI Disperse Blue 79) energy level dyes. UV-visible spectroscopy, HPLC-DAD and COD analysis were performed to follow the removal of color from effluent. The results indicated that color removal rates up to 100% and COD removal rates up to 68% could be achieved via ozonation. HPLC analysis and UV-vis analysis were performed for all of the dyes, and a degradation mechanism was proposed for CI Disperse Blue 79.

This paper describes a method for the determination of six phthalate esters (PEs) in artificial saliva using solid phase extraction (SPE) and gas chromatography–mass spectrometry (GC–MS). A new material was developed to isolate the PEs from artificial saliva. Poly(ethylene glycol dimethacrylate-N-methacryloyl-L-tryptophan methyl ester) (poly(EGDMA-MATrp)) microspheres (average diameter = 106–300 μm) were synthesised and characterised. Several different parameters, such as pH, adsorption time and adsorbent amount, which affect SPE, were carefully optimised by central composite design (CCD). The best analytical conditions for the simultaneous determination of the analytes from a spiked artificial saliva sample were found to be a pH of 6.8, an adsorption time of 90 min, and an adsorbent amount of 1.8 g L−1, using dichloromethane as the elution solvent. These conditions were applied to study the migration of PEs found on various children's toys into saliva.

Yilmaz, Veysel/0000-0002-2849-3332 WOS: 000318209100017 PubMed: 23466323 A new palladium(II) complex, [Pd(ppeieo)(inap)]center dot DMSO (ppeieo = (1E,2E)-phenyl-[(1-phenylethyl)imino]-ethanal oxime and imp = isonitrosoacetophenone) has been synthesized and characterized by elemental analysis, UV-vis, IR, NMR. X-ray diffraction analysis of the DMSO solvate of the complex shows that the palladium(II) ion is coordinated in a distorted square-planar geometry by ppeieo and map, which is formed during the hydrolysis of ppeieo. DFT (B3LYP/LANL2DZ) calculations on the complex have been carried out to correlate geometry and spectroscopic properties such as electronic, vibrational and NMR chemical shifts. The complete vibrational frequency assignments were made and the calculation results were applied to simulate infrared spectra of the title compound which shows good agreement with observed spectra. The calculated HOMO and LUMO energies show that several transitions including the pi -> pi* and charge transfer occur within the molecule. The chemical shifts reasonably correspond to the calculated spectra. (c) 2013 Elsevier B.V. All rights reserved. Uludag UniversityUludag University This work is a part of a Research Project OUAP(F)-2012/12. We thank Uludag University for the financial support given to the project.

A series of long-chain N-arylundecanamides containing benzimidazole thioethers (2a–e) were synthesized and characterized by FT IR, 1H NMR, and elemental analysis. The corrosion inhibitory properties of these compounds on cold rolled low carbon steel metal coupons were investigated by weight loss measurements in acidic media. Surface characterization studies of the metal coupons used were performed by contact angle measurements using the sessile-drop method. In addition, the 3D image of the metal surface was measured using an optical profilometer. The results obtained from these analyses showed that almost all of the tested compounds between 25–150-ppm concentrations in acidic media are good to excellent corrosion inhibitors with the values of percentage inhibition efficiency (η) = 77–99%. Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

In this study, we prepared surface plasmon resonance (SPR) sensor using the molecular imprinting technique for myoglobin detection in human serum. For this purpose, we synthesized myoglobin imprinted poly(hydroxyethyl methacrylate-N-methacryloyl-t-tryptophan methyl ester) [poly(HEMA-MATrp)] nanofilm on the surface of SPR sensor. We also synthesized non-imprinted poly(HEMA-MATrp) nanofilm without myoglobin for the control experiments. The SPR sensor was characterized with contact angle measurements, atomic force microscopy, X-ray photoelectron spectroscopy, and ellipsometry. We investigated the effectiveness of the sensor using the SPR system. We evaluated the ability of SPR sensor to sense myoglobin with myoglobin solutions (pH 7.4, phosphate buffer) in different concentration range and in the serum taken from a patient with acute myocardial infarction. We found that the Langmuir adsorption model was the most suitable for the sensor system. The detection limit was 87.6 ng/mL. In order to show the selectivity of the SPR sensor, we investigated the competitive detection of myoglobin, lysozyme, cytochrome c and bovine serum albumin. The results showed that the SPR sensor has high selectivity and sensitivity for myoglobin. (C) 2013 Published by Elsevier B.V.

Response surface methodology was used to optimize experimental conditions for ultrasonic-assisted extraction of phenolic compounds from blackberry leaves. The Box-Behnken design (BBD) was employed for the optimization of extraction parameters in terms of total phenolics and antioxidant capacity. The optimal conditions for results of ABTS and CUPRAC were HCl concentration 0.41 and 0.45 M, methanol concentration 61 and 64% (v/v), extraction temperature 66 and 68 °C and extraction time 105 and 117 min, respectively. The experimental values agreed with those predicted values within a 95% confidence level, thus indicating the suitability of response surface methodology in optimizing the ultrasound-assisted extraction of phenolic compounds from blackberry leaves. The results showed that phenolic compounds present in blackberry leaves exhibited significant antioxidant properties. Seven phenolic compounds such as ellagic acid, caffeic acid, chlorogenic acid, quercetin, myricetin, kaempferol and kaempferol 3-β- d -glucopyranoside were determined in blackberry leaves by HPLC-DAD after extraction at optimum conditions.

Response surface methodology was used to optimise experimental conditions for ultrasonic-assisted extraction of phenolic compounds from Artemisia absinthium. The central composite design was employed, the extracts were characterised by the determination of total phenolic content and antioxidant capacity. The total phenolic contents of extracts were determined by Folin method and also total antioxidant capacities of extracts were determined by ABTS and CUPRAC methods. The phenolic compounds of A. absinthium at optimum extraction conditions were determined by HPLC-DAD. The optimum conditions were determined as HCl concentration between 0.41 and 0.44 mol/L, methanol volume between 55% and 59% (v/v), extraction temperature between 64 and 70 degrees C, extraction time between 101 and 107 min. The experimental values agreed with those predicted within a 95% confidence level, thus indicating the suitability of response surface methodology in optimising the ultrasound-assisted extraction of phenolic compounds from A. absinthium.

The effects of the nature and amount of base, substrate structure, amount of added water and solvent on the condensation of carbonyl compounds with cyclopentadiene in the presence of secondary amines were investigated. Based on these studies, a new efficient and green synthesis of fulvenes was developed. United States Department of Health & Human Services National Institutes of Health NIH National Institute of General Medical Sciences (NIGMS) (1SC1GM082340) National Science Foundation (DBI-0521342) (DUE-9451624)

Raspberry and blackberry cultivars were assayed for total phenol content by enzymatic method using immobilized horseradish peroxidase (HRP). The HRP was immobilized on the styrene–divinylbenzene–polygluteraldehyde (STY–DVB–PGA) beads. Total phenol content determined by immobilized and free enzymatic methods was compared with those obtained by applying the Folin–Ciocalteu method. The total phenol content by immobilized HRP method ranged from 254 to 973 mg gallic acid equivalent (GAE) per 100 g fw as well as 105 to 435 mg ellagic acid equivalent (EAE) per 100 g fw in raspberry and blackberry cultivars. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical values were correlated with total phenol content in raspberry using immobilized enzymatic method as GAE (R2 = 0.7450, P = 0.05) and EAE (R2 = 0.7449, P = 0.05). All antioxidant activity values were highly correlated with total phenol content in blackberry using free and immobilized enzymatic methods as GAE (R2 = 0.9777 and 0.9223, P = 0.05 respectively) and EAE (R2 = 0.9979 and 0.9223, P = 0.05 respectively). A significant additivity was observed using individual phenolic compounds by immobilized enzymatic method as 95% (GAE) and 90% (EAE). These results show that the immobilized enzymatic assay can be applied to determine the total phenol content of berry fruits, which is more specific and not affected by interfering compounds.

A convenient and simple wet acid digestion method was developed for the determination of Cd and Pb concentrations in polyvinyl chloride matrices by atomic absorption spectrometry. Response surface methodology (RSM) was used to optimise the conditions for maximum recovery and to understand the significance and interaction of the factors affecting the recovery of Cd and Pb. The central composite design was employed to evaluate the effects of nitric acid volume (2.6-9.4 mL), sulphuric acid volume (0.6-7.4 mL) and certified reference material (CRM) amount (0.1-0.5 g) on the metal recoveries (60 min, 200 degrees C and 20 min, 250 degrees C). The accuracy was also evaluated using the polyvinyl chloride reference material Fluxana FLX-PVC2. The apparent recoveries of the elements relative to the certified values ranged from 0.94 (Cd) to 0.92 (Pb). The method's detection limits were found to be 1.6 and 6.4 mg kg(-1) for Cd and Pb, respectively.

Horseradish Peroxidase (HRP) was immobilized by covalent binding onto glutaraldehyde cross-linked chitosan beads and these beads were used for determination of total phenolic content in Prunella L. species. Central composite design (CCD) was employed to optimize the conditions for the maximum HRP activity and to understand the significance and interaction of the factors affecting the activity of immobilized HRP. The results indicated that enzyme concentration and immobilization time were significant factors for the immobilization of HRP. The optimum conditions were determined as enzyme concentration 0.25 mg mL(-1), pH 8.0 and immobilization time 20h. The recovered activity was obtained as 81% after immobilization under optimal conditions. Total phenol content was determined in four Prunella L. species (Prunella vulgaris L., Prunella laciniata (L.) L., Prunella orientalis Bornm., Prunella grandiflora L.) extracted using methanol, water and methanol/water (4 : 1, v/v). The enzymatic method is based on the spectrophometric measurement of the final quinone-imine colored product, absorbing at 510 nm, by HRP oxidation in presence of hydrogen peroxide. The results were compared with those obtained by applying the Folin method. The highest total phenol content was obtained with the methanol/water (4 : 1, v/v) extract of Prunella vulgaris L. by immobilized HRP method (63.75 mg gallic acid equivalent (GAE) per g dried plant). Operational stability was determined with immobilized HRP and it indicated that a small enzyme deactivation (15%) occurred after 10 consecutive uses.

Four species of Prunella L. (Prunella vulgaris L., Prunella laciniata L., Prunella grandiflora L. and Prunella orientalis Bornm.) belong to the family of Lamiaceae and representing popular Western and Chinese herbal medicine were examined for the content of phenolic compounds. Phenolic acids (rosmarinic acid, caffeic acid, ferulic acid, chlorogenic acid, protocatechuic acid), flavonoids (rutin, quercetin) in different quantitative proportions depending on extracts were determined by the rapid, selective and accurate method combining solvent/acid hydrolysis extraction and high performance liquid chromatography-diode array detection (HPLC-DAD). Water, methanol, butanol, acetonitrile, ethyl acetate, hexane and their acidic solutions were used to examine the efficiency of different solvent systems for the extraction of phenolic compounds. Acid hydrolysis extraction was established as the most suitable extraction method for phenolic compounds.

Poly(ethylene glycol dimethacrylate–1-vinyl-1,2,4-triazole) [poly(EGDMA–VTAZ)] beads with an average diameter of 100–200 μm were obtained by the copolymerization of ethylene glycol dimethacrylate (EGDMA) with 1-vinyl-1,2,4-triazole (VTAZ). The copolymer hydrogel bead composition was determined by elemental analysis and was found to contain 5 EGDMA monomer units for each VTAZ monomer unit. The poly(EGDMA–VTAZ) beads were characterized by swelling studies and scanning electron microscopy (SEM). The specific surface area of the poly(EGDMA–VTAZ) beads was found 65.8 m2/g. Cu2+ ions were chelated on the poly(EGDMA–VTAZ) beads. The Cu2+ loading was 82.6 μmol/g of support. Cu2+-chelated poly(EGDMA–VTAZ) beads with a swelling ratio of 84% were used in the immobilization of Aspergillus niger glucoamylase in a batch system. The maximum glucoamylase adsorption capacity of the poly(EGDMA–VTAZ)–Cu2+ beads was 104 mg/g at pH 6.5. The adsorption isotherm of the poly(EGDMA–VTAZ)–Cu2+ beads fitted well with the Langmuir model. Adsorption kinetics data were tested with pseudo-first- and second-order models. The kinetic studies showed that the adsorption followed a pseudo-second-order reaction model. The Michaelis constant value for the immobilized glucoamylase (1.15 mg/mL) was higher than that for free glucoamylase (1.00 mg/mL). The maximum initial rate of the reaction values were 42.9 U/mg for the free enzyme and 33.3 U/mg for the immobilized enzyme. The optimum temperature for the immobilized preparation of poly(EGDMA–VTAZ)–Cu2+–glucoamylase was 65°C; this was 5°C higher than that of the free enzyme at 60°C. The glucoamylase adsorption capacity and adsorbed enzyme activity slightly decreased after 10 batch successive reactions; this demonstrated the usefulness of the enzyme-loaded beads in biocatalytic applications. The storage stability was found to increase with immobilization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

The binary ligand complexes formed between acetohydroxamic acid (Aha) and benzohydroxamic acid (Bha) ligands and selected transition metals (Sc(III), Y(III), and La(III)) were investigated potentiometrically in aqueous solution at (25 +/- 0.1) degrees C and I = 0.10 M NaCl to determine the protonation constants of the free ligands and stability constants of the binary complexes. The complexation model for each metal-ligand system was established from the potentiometric data using the software program BEST. The concentration distributions of the various metal-ligand complexes formed in solution were also evaluated. The complex stability was found to follow the trend Sc(III) > Y(III) > La(III) based on the ionic radius of the metal ions.

The determination of six phthalate acid esters was achieved in artificial saliva using gas chromatography–mass spectrometry following activated carbon enrichment of samples. Central composite experimental design was applied to optimize method parameters, such as pH, adsorption time and amount of activated carbon. The best compromise of analytical conditions for the simultaneous determination of analytes from spiked artificial saliva were found to be: pH (3), adsorption time (30 min), activated carbon amount (1.8 g L−1) and elution solvent (chloroform). These conditions were applied to study the migration of phthalate acid esters from different children's toys into saliva. A horizontal agitation method was applied to extract the analytes from plastic toys into saliva for 2 h at 37 °C. The detection limits of the method were in the range of 1.3–5.1 μg L−1, while the relative standard deviation (%) values for the analysis of 100 μg L−1 of the analytes were below 3.0% (n = 5). Di-2-ethylhexyl phthalate was the main analyte found in these samples.

A new method for determination of total phenolic content of four Prunella L. species was developed by immobilizing horseradish peroxidase (HRP) on styrene-divinylbenzene-polygluteraldehyde (STY-DVB- PGA) polymer. The method is based on the spectrophotometric measurement of the final quinone-imine colored product, absorbing at 510 nm, by horseradish peroxidase oxidation in presence of hydrogen peroxide. The effects of solvents were investigated for the extraction of phenolic compounds in Prunella L. plants. HRP was covalently attached on the STY-DVB-PGA with 90% efficiency at optimum immobilization conditions. The total phenol contents ranged from 4 to 152 mg GAE per g of dried sample for pure solvents and ranged from 19 to 763 mg GAE per g of dried sample for acidic extracts using the immobilized enzymatic method. STY-DVB-PGA beads are a good potential support for the immobilization of HRP enzyme and can be used for determination of the total phenolic content of plants. In the analysis of four Prunella L. species, high correlations were obtained between enzymatic and Folin methods, supporting the validity of the enzymatic method proposed. The enzymatic (free/immobilized) methods are more specific and rapid than the Folin method. Acidic solvents are more effective than pure solvents for extraction of phenolic compounds in Prunella L. species.

Graphical abstract Electric chatacterization of organic field effect transistors with PVT dielectric layer: Pentacene is used as active layer in p-channel device; Fullerene is the active layer in n-channel device. Channel length is 2mm, channel width is 0.06mm. Research highlights ► PVT shows low leakage current and high breakdown voltage. ► Both n-channel and p-channel OFET devices give low threshold voltage and are lack of hysteresis. ► Excellent film formation property of PVT allows for fabricating low voltage operation OFET devices. ► All solution processed polymer ambipolar OFET device is realized via layer by layer coating., Water soluble poly(1-vinyl-1,2,4-triazole) (PVT) as a novel dielectric layer for organic field effect transistor is studied. Dielectric spectroscopy characterization reveals it has low leakage current and rather high breakdown voltage. Both n-channel and p-channel organic field effect transistors are fabricated using pentacene and fullerene as active layers. Both devices show device performances with lack of hysteresis, very low threshold voltages and high on/off ratios. Excellent film formation property is utilized to make AlOx and thin PVT bilayer in order to decrease the operating voltage of the devices. All solution processed ambipolar device is fabricated with simple spin coating steps using poly(2-methoxy-5-(2-ethyl-hexyloxy)-1,4-phenylenevinylene) (MEH–PPV) end capped with polyhedral oligomeric silsesquioxanes (POSS) as active layer. Our investigations show that PVT can be a very promising dielectric for organic field effect transistors.

This paper describes the application of LFER in the form of Taft correlation to understand the mechanism of the esterification of propanoic acid with different alcohols over heterogeneous catalyst, Dowex 50Wx4. The rate constant (k1) in the rate equation decreases with change of alcohols in the order methanol, ethanol, n-propyl, n-butyl, n-pentyl, iso-butyl, iso-propyl and sec-butyl (2-buthanol). The reaction of propanoic acid with alcohols fits the Taft equation, log k1/kCH3= 1.0061 Es- 0.0012, which implies that the steric effect of the substituent governs that reaction and the mechanism is similar between the different alcohols. The experimental results were modelled according to a simple second-order model. It was found that the equilibrium constant of this reaction does not depend on the structure of the organic alcohols, and has for 333 K the value 4.04.

Sengul, Abdurrahman/0000-0001-6851-4612; Yilmaz, Veysel/0000-0002-2849-3332 WOS: 000287942300011 Two new copper(II) complexes of saccharinate (sac) with bis(2-pyridylmethyl)amine (bpma) and N,N'-bis[1-(pyridin-2-yl)ethylidene]ethane-1,2-diamine (bapen), [Cu(bpma)(sac)2]center dot H2O (1) and [Cu(bapen)(sac)2] (2), were synthesized and characterized by elemental analysis, TG-DTA, X-ray diffraction, and UV/Vis and IR spectroscopy, respectively. In 1, the copper(II) ion is coordinated by two N-bonded sac ligands, and three nitrogen atoms of bpma, in a distorted square-pyramidal coordination arrangement, whereas the arrangement around the copper ion in 2 is a distorted octahedron with two N-coordinated sac ligands and a tetradentate bapen ligand. In addition to hydrogen bonding involving the water molecule in 1, the mononuclear species of 1 and 2 arc further connected by weak intermolecular C-H center dot center dot center dot pi and C-H center dot center dot center dot O interactions to form a three-dimensional network. Both complexes are luminescent at room temperature and their emissions seem to be due to ligand-based it pi-pi* transitions.

Yilmaz, Veysel/0000-0002-2849-3332 WOS: 000294316700006 New palladium(II) and platinum(II) complexes of saccharinate (sac), trans-[Pd(PY)(2)(sac)(2)] (1), cis-[Pt(py)(2)(sac)(2)] (2), trans-[Pd(3-acpy)(2)(sac)(2)] (3) and cis-[Pt(3-acpy)(2)(sac)(2)] (4) (py = pyridine and 3-acpy = 3-acetylpyridine) have been synthesized. Elemental analysis, UV-Vis, IR, NMR and TG/DTA characterizations have been carried out. The structures of 1-4 were determined by X-ray diffraction. The palladium(II) and platinum(II) ions are coordinated by two N-bonded sac ligands, and two nitrogen atoms of py or 3-acpy, forming a distorted square-planar geometry. The palladium(II) complexes (1 and 3) are trans isomers, while the platinum(II) complexes (2 and 4) are cis isomers. The mononuclear species in the solid state are connected by weak intermolecular C-H center dot center dot center dot O hydrogen bonds, C-H center dot center dot center dot pi and pi center dot center dot center dot pi stacking interactions. The platinum(II) complexes show significant fluorescence at the room temperature. (C) 2011 Elsevier Ltd. All rights reserved. TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) This work is a part of a research project 106T664. We thank TUBITAK for the financial support given to the project.

The asphaltene has been obtained from asphalt cement with penetration grade 60, which is extracted from crude Libya petroleum. The elemental composition and some structural properties of the asphaltene samples are determined by various methods, such as SEM, infrared spectroscopy, and X-ray analysis. Some experiments are performed on 1H dynamic nuclear polarization (DNP) in a number of asphaltene suspensions in organic solvents. The frequency dependence of the DNP enhancement under conditions of weak EPR saturation in a low magnetic field is obtained and interpreted as the EPR line shape of some free radicals present in the samples.

Nilufer stream (Bursa, Turkey) receives domestic and industrial discharges containing heavy metals as well as organic pollutants. The speciation profiles of discharge waters were built up for chromium(Ill) and chromium(VI) ions in samples those were collected on a monthly basis from two stations in September 1996-August 1998 period. They indicate that chromium(III) contents of samples from station I that was in leather tanneries region were higher than of samples from station 11 that was in automotive and textile industries region. In order to remove Cr(III) ion from discharge waters by complexometry, the removing tendencies of some ligands such as salicylic acid and salicylic acid derivatives were ordered by means of the speciation diagrams of Cr(III):ligand systems, the working pH values and reduced concentrations of Cr(III).

Demir, Selcuk/0000-0002-5719-7145; Yilmaz, Veysel/0000-0002-2849-3332; YILMAZ, Fatih/0000-0002-7711-0975 WOS: 000268312500009 Cobalt(II) and zinc(II) succinato (suc) coordination polymers with nicotinamide (nia), {[Co(mu-suc)( H2O)(2) (nia)(2)] . 2H(2)O}(n) (1) and {[Zn(mu-suc)(H2O)(2)(nia)(2)] . 2H(2)O}(n) ( 2) have been synthesized and characterized by elemental analyses, magnetic moments, IR and TG-DTA. Single-crystal X-ray analyses of 1 and 2 reveal that these complexes are isostructural and crystallize in triclinic space group P (1) over bar. Complexes 1 and 2 are 1-D coordination polymers, in which the metal( II) ions exhibit an octahedral geometry with two suc, two nia and two aqua ligands. The nia ligand is N-bonded, while the suc ligand bridges the metal centers through the carboxylate groups. The 1D chains are further assembled to form 3D networks by strong N-H center dot center dot center dot O and OW-H center dot center dot center dot O hydrogen bonds. IR spectra confirm the coordination modes of both suc and nia ligands, while TG-DTA data are in agreement with the crystal structures. Fluorescent analysis in the solid state shows that all complexes display intraligand (pi-pi*) emissions of nia.

Yilmaz, Veysel/0000-0002-2849-3332; Sahin, Onur/0000-0003-3765-3235 WOS: 000267944800044 Three new copper(II) complexes of 5,5-diethlybarbiturate (barb), [Cu(barb)(2)(dmen)] center dot 0.5H(2)O (dmen = N, N-dimethylethylenediamine) 1, [Cu(barb) 2(bapa)] (bapa = bis(3-aminopropyl) amine) 2, and [Cu(barb)(apen)](barb) center dot 2H(2)O (apen = N, N'-bis(3-aminopropyl) ethylenediamine) 3, have been synthesized and characterized by chemical, spectroscopic and thermal methods. Single crystal X-ray diffraction studies revealed that all complexes are mononuclear. The copper(II) ion exhibits a square-pyramidal coordination geometry in 1 and 3, but a trigonal-bipyramidal geometry in 2. The barb ligand shows different coordination modes. 1 presents the unequal coordination of the barb ligands: one is monodentate (N) and the other one is bidentate (N, O). In 2, both barb ligands are N-coordinated, whereas in 3, one barb ligand is N-coordinated, while the second barb ligand behaves as a counter-ion. The dmen, bapa and apen ligands act as bi-, tri- and tetradentate ligands, respectively. All complexes display a hydrogen-bonded network structure. The IR spectroscopic analysis shows that the nu(CO) stretching frequencies do not correlate predictably with the coordination mode of the barb ligand in 1. Thermal analysis data for 1-3 are in agreement with the crystal structures. (C) 2009 Elsevier B. V. All rights reserved. Uludag UniversityUludag University [F-2008/56] We thank the research fund of Uludag University for the financial support given to the research project (F-2008/56).

A dynamic combinatorial library (DCL) based on benzylidene exchange reactions between imidazolidin-1-ol, nitrone and oxadiazinane (INO) ring-chain-ring tautomers at room temperature is created. The probable mechanism of the reaction is discussed based on Hammett type correlation analyses. The equilibria in the DCL are defined as interconversion of INOAr-X to INOAr-Y as a result of reactions with the corresponding aldehydes Y-ArCHO and X-ArCHO and are shown to depend on the σ constants of the substituents and are described by a simple equation log K XY = ρσ dif + log K XY(X = Y) . The prediction of K XY for any INOAr-X and INOAr-Y interconversion requires only the experimental values of ρ and the known Hammett σ constants of the substituents. The effect of Zn(II) and CF 3 SO 3 H on the DCL equilibria is also reported.

X-ray crystallographic analysis of the title organic ion–pair complex, C18H18NO2 + · ClO4 −, reveals that 6,7-dimethoxy-2-methyl-4-phenylisoquinolinium cation is co-crystallized with perchlorate counter-anions in 1:1 ratio. The complex crystallizes in space group P 2 1 /n, with a = 8.0226(7) A, b = 12.2552(7) A, c = 17.9734(16) A, β = 93.908(7) °, Z = 4, D x = 1.431 g/cm3. Aromaticity of isoquinolinium fragment is considerably deformed by the existence of C–H···O type weak H-bonds, leading to chains of topology C 3 3(12)[R 1 2 (4)] running along b-axis of the unit cell and pseudo-cyclic centrosymmetric R 4 4 (24)[2R 1 2 (4)] synthons. The weak H-bonds serve to stabilize both the extended structure and molecular geometry of the title complex, in particular the disordered perchlorate anion whose components adopt a distorted tetrahedron. Molecular and the extended structure of 6,7-dimethoxy-2-methyl-4-phenylisoquinolinium perchlorate, C18H18NO2 + · ClO4 −, were determined by single crystal X-ray diffraction study.