Analytical Sciences
Online ISSN : 1348-2246
Print ISSN : 0910-6340
ISSN-L : 0910-6340
Volume 19 , Issue 6
Showing 1-34 articles out of 34 articles from the selected issue
Rapid Communications
Original Papers
  • Xiaodi YANG, Shuping BI, Xiaoliang YANG, Li YANG, Jun HU, Jian LIU, Zh ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 6 Pages 815-821
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    Complexation and conformational studies of coenzyme NAD+ with aluminum were conducted in acidic aqueous solutions (pH 2 - 5) by means of potentiometry as well as multinuclear (1H,13C,31P,27Al) and two-dimensional (1H,1H-NOESY) NMR spectroscopy. These led to the following results: (1) Al could coordinate with NAD+ through the following binding sites: N7′ of adenine and pyrophosphate free oxygen (OA1,ON1,OA2) to form various mononuclear 1:1 (AlLH23+,AlLH2+) and 2:1 (AlL2-) species, and dinuclear 2:2 (Al2L22+) species. (2) The conformations of NAD+ and Al-NAD+ depended on the solvents and different species in the complexes. The results suggest the occurrence of an Al-linked complexation, which causes structural changes at the primary recognition sites and secondary conformational alterations for coenzymes. This finding will help us to understand role of Al in biological enzyme reaction systems.
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  • Nobutoshi KIBA, Toyonari TOKIZAWA, Sayaka KATO, Masaki TACHIBANA, Kazu ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 823-827
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    A micromachined flow cell (overall size; 25 × 25 × 1 mm3) was designed for the fast determination of hydrogen peroxide, based on a luminol-H2O2 chemiluminescence reaction catalyzed by immobilized peroxidase (POD). The flow cell consisted of a sandwich of anisotropically etched silicon and glass chips and contained a spiral channel (20 turns, 50 cm long, 150 μm wide, 20 μm depth, channel volume 1.4 μl) and two holes (1 mm diameter). POD was covalently immobilized with 3-(trimethoxysilyl)propyldietylenetriamine and glutaraldehyde on the inner surface of the channel. The chip was placed in front of a window of a photomultiplier tube and used as a flow cell in a single-line flow-injection analysis system using a luminol solution as a carrier solution. The sample volume for one measurement was 0.2 μl. The maximal sampling rate was 315 h-1 at a carrier solution flow rate of 10 μl min-1. A calibration graph for H2O2 was linear for 5 nM - 5 μM; the detection limit (signal-to-noise = 3) was 1 nM (7 fg in 0.2 μl injection). The H2O2 concentration in rainwater was determined using this sensor system.
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  • Toshio YAO, Kazuya KOTEGAWA
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 6 Pages 829-833
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    A flow injection biosensor system was proposed for the highly sensitive detection of 2,4,6-trichlorophenol (2,4,6-TCP). The system is based on the preoxidation by ceric sulfate to the corresponding benzoquinone (2,6-dichloro-1,4-benzoquinone: 2,6-DC-1,4-BQ), which was characterized using cyclic voltammetry, hydrodynamic voltammetry, and UV-vis spectrophotometry. The laccase-based biosensor used in this analytical system responded sensitively to 2,4,6-TCP after the preoxidation by ceric sulfate. The response could be based on the bioelectrocatalytic recycling of oxidation product (2,6-DC-1,4-BQ) between laccase membrane and the electrode, because the oxidation product (2,6-DC-1,4-BQ) of 2,4,6-TCP was an electrochemically reversible redox species. The signal current was linearly related to the 2,4,6-TCP concentrations in a dynamic range of 2 nM - 2 μM; the slope and the y-intercept of the straight line were 1150 nA μM-1 and 0.88 nA, respectively. The detection limit was 1.2 nM (S/N = 3) for a 20 μl injection. Among a variety of chlorophenols and some phenolic compounds, the only interferent was 2,4-dichlorophenol.
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  • Tomohiro KYOTANI, Satoshi KOSHIMIZU
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 835-841
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    The selective enrichment behavior of a labile substance, such as hydroxides, to the surface of particular mineral particles in river water was clarified by scanning electron microscopy/energy dispersive X-ray microanalysis (SEM-EDX). Individual particles other than diatom collected on a 0.45 μm filter from the Fuji and Sagami rivers, central Japan, were analyzed by SEM-EDX and classified into seventeen groups according to the chemical composition and shape. Phosphorus, sulfur, chlorine, manganese and copper detected in each particle collected on the 0.45 μm filter could be successfully used as effective indicators of labile substance secondarily formed and adsorbed afresh in river water, because the detection frequencies of such elements are quite low, or negligible, in fresh mineral particles derived from igneous rocks. The labile substance adsorbed on mineral particles collected on the 0.45 μm filter was also evaluated by dilute-acid leaching, followed by inductively coupled plasma mass spectrometry (ICP-MS). Almost all parts of the manganese detected in individual particles were those adsorbed afresh as hydroxides together with iron and aluminum. Also, anionic elements, such as phosphorus, sulfur and chlorine, formed complexes with the hydroxides and/or were incorporated in them. Mg and/or Ca-rich aluminosilicate groups were the most effective adsorbers of such labile species. However, Si-rich and Na-, K- and Na-Ca rich aluminosilicates did not significantly adsorb the labile substance. Consequently, the remarkable selectivity was clarified in the adsorption process of labile substance to individual mineral particles in river water.
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  • Bangwoo HAN, I.Wuled LENGGORO, Mansoo CHOI, Kikuo OKUYAMA
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 843-851
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    Cluster ions and residue nanoparticles with sizes below 30 nm were generated by electrospraying (ES) and drying droplets of pure water, tap water, and aqueous solutions of salts. The mobility spectra of the cluster ions between 9.1 and 9.3 × 10-5 m2/(V s) were measured using a differential mobility analyzer (DMA) operated at room temperature and atmospheric pressure. A modified Faraday cup and a condensation nucleus counter were used for detection. The concentrations of total residue/contaminants in the water were determined as a function of sizes of measured aerosol particles and of the initial droplets. Method detection limits were at sub-ppb level for pure water and sub-ppm level for tap water. ES/DMA is capable of simultaneously measuring the mobility distribution of cluster ions and concentration of total residue present in water samples.
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  • Tetsuo SAKAMOTO, Azusa YAMAMOTO, Masanori OWARI, Yoshimasa NIHEI
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 853-857
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    A combined apparatus of a supercritical CO2 extractor (SFE) and a time-of-flight mass spectrometer (TOF-MS) was developed aiming at the direct analysis of extracts. A fused-silica capillary acts as both a pressure restrictor and an effluent injection nozzle into the TOF-MS. The tip of the nozzle was narrowed by melting and abrasion so that a greater pressure drop occurred at the tip. In the TOF-MS chamber, differential pumping between the main and ionization chamber kept the pressure in the ionization chamber at around 10-3 Pa when the SFE pressure was at 9.7 to 29.4 MPa. The TOF-MS performance, a mass resolution of 263 at m/z = 146, and a sensitivity of 1.6 ng (p-dichlorobenzene) were certified by direct injection of a standard organic solution. Online detection of SFE effluent containing naphthalene, p-dichlorobenzene, phenanthrene and pyrene were successfully performed by the TOF-MS only for 48000 ionization cycles corresponding to 7.5 s.
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  • Tadashi OHKUBO, Ritsuko SHIMOYAMA, Koichi OTANI, Keizo YOSHIDA, Hisash ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 859-864
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    A high-performance liquid chromatographic (HPLC) method has been developed for the simultaneous determination of fluvoxamine and its major metabolite fluvoxamino acid in plasma. Fluvoxamine and fluvoxamino acid in plasma were extracted using a C18 bonded-solid phase cartridge, followed by C4 reversed-phase HPLC separation. Fluvoxamine, fluvoxamino acid and moperone as an internal standard were detected by ultraviolet absorbance at 254 nm. It was possible to determine both fluvoxamine and fluvoxamino acid in the concentration range of 25.0 - 200.0 ng/mL, respectively. The detection limits of both fluvoxamine and fluvoxamino acid were 10.0 ng/mL, respectively. The mean recoveries of fluvoxamine and fluvoxamino acid added to plasma were more than 94.0% and 96.5%, with a coefficient of variation of less than 7.6% and 8.2%, respectively. This method has been used for the simultaneous determination of steady-state plasma concentration (Css) of fluvoxamine and fluvoxamino acid in depressive patients treated with 200 mg of oral fluvoxamine dosed as 100 mg twice-daily. The Css values of fluvoxamine and fluvoxamino acid in twelve Japanese patients were showed individual variations, which wree in the range of 48.3 - 532.9 ng/ml and 35.6 - 307.1 ng/ml, respectively.
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  • Akira KOTANI, Yuzuru HAYASHI, Rieko MATSUDA, Fumiyo KUSU
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 865-869
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    A chemometric tool based on the Function of Mutual Information (FUMI) theory can provide a relative standard deviation (RSD) without repetitive measurements in high-performance liquid chromatography with electrochemical detection (HPLC-ECD). Two parameters: precision (= information content) φ and efficiency (= information content/time) θ, which were calculated from predicted RSD based on the FUMI theory, were used to optimize HPLC-ECD conditions, such as applied potential, flow rate, column length, and size of ODS porous packing. We selected catechins as analytes, and found that the most optimum applied potential and flow rate were +600 mV vs. SCE and 0.9 mL/min, respectively, because they gave the largest φ and θ values. Buffer concentration in mobile phase is less effective for giving large φ and θ values. Since the FUMI theory makes it possible to predict RSD without repetitive measurements, the present method saves considerable amounts of chemicals and experimental time, and was found to be useful for the optimization of experimental conditions for determination by HPLC-ECD.
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  • Javad ZOLGHARNEIN, Sheida HOSSEINI, Golamhassan AZIMI, Mohammad Reza S ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 871-875
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    Potassium-decyl-18-crown-6 was used as a highly selective and efficient carrier for uphill transport of silver as AgBr2- complex ion through a chloroform bulk liquid membrane. When thiosulfate anion was used as a metal ion acceptor in the receiving phase the amounts of silver transported across the liquid membrane after 120 and 180 min were 87.0 ± 1.8% and 96.0 ± 1.9%, respectively. The selectivity and efficiency of silver transport from aqueous solution containing Cu2+, Zn2+, Ni2+, Cd2+, Pb2+ and Fe3+ ions were investigated. In the presence of EDTA at pH = 4 as suitable masking agent in the source phase, the interfering effects of Pb2+ and Fe3+ ions were diminished drastically.
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  • S.M. GOLABI, J. MOHAMMADI
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 877-881
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    A new wire-coated silver ion-selective electrode with a wider concentration range (10-7 M - 10-1 M) was developed using 2-mercaptobenzothiazole (MBT) as a neutral ionophore. An optimum mixture of PVC, ionophore, dioctylphtalate (DOP) as a plasticizer and sodium tetraphenylborate (NaTPB) as an ion-pairing agent was used in preparing the coatings. The effect of various parameters, such as the electrode bed nature, coating composition and solution pH, on the efficiency of the electrode is described. It has been shown that platinum acts as a more suitable bed for electrode preparation, and exhibits a slope of 59.5 ± 1 mV over the whole range of studied concentrations. The selectivity coefficient of the electrode towards various interfering cations as well as its reproducibility, response time and lifetime of the electrode were estimated. The developed electrode was successfully used for the determination of trace amounts of silver in human hair and photographic waste as real samples and in the potentiometric titration of halides as an indicator electrode.
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  • Jiagen LV, Zhujun ZHANG, Lirong LUO
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 883-886
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    An on-line Ag/Al galvanic cell was studied and employed to generate electrochemiluminescence (ECL) of calcein blue. The potential of the galvanic cell could be adjusted by varying the components of flow reagent or by using different metals to substitute for Ag or Al. The reported cell exhibited perfect capability of supplying a stable potential for ECL generation. Because the weak ECL of calcein blue could be greatly sensitized in the presence of calcium in alkaline solution, calcium contents in milk and vegetable samples were assayed; the results were validated with ICP-AES method. The method gave linear results in 1.0 × 10-4 mol L-1 to 8.0 × 10-6 mol L-1 calcium concentration range and the 3σ limit of detection was to be 2.0 × 10-6 mol L-1. Experiment results imply that this model of ECL detection could be applied for instrument miniaturization with easy fabrication.
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  • Naoya NISHI, Daisuke HOBARA, Masahiro YAMAMOTO, Takashi KAKIUCHI
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 887-890
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    Sum frequency vibrational spectra for hexadecanethiol (HDT) adsorbed on thin gold film deposited on the surface of a CaF2 prism have been measured using total-internal reflection broad-bandwidth sum frequency generation (TIR-BBSFG) spectroscopy. The bands attributed to the CH3 symmetric and asymmetric stretching vibrational modes were observed in the sum frequency vibrational spectra. The orientation of the methyl groups was analyzed using the ratio of the intensities of the two modes. The methyl groups of HDT on the thin gold film were much more randomly orientated than those on Au(111).
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  • Yoshio TAKAHASHI, Naoya OHTAKU, Satoshi MITSUNOBU, Kouichi YUITA, Masa ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 891-896
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    The details of a method used to determine the As(III)/As(V) ratio in soil by arsenic K-edge XANES spectroscopy are described. The spectra of mixtures of NaAs(III)O2 and NaH2As(V)O4, conducted for an As(III)/As(V) calibration, were well-fitted by combining normalized spectra of NaAsO2 and Na2HAsO4, where the coefficients multiplied by the normalized spectra were identical to the molar ratio of As(III) and As(V) in the mixtures. XANES spectra of arsenic in soil samples could also be fitted by a linear combination of the spectra of NaAsO2 and Na2HAsO4, which enabled us to estimate the As(III)/As(V) in a soil containing 10.2 mg/kg arsenic. The As(III)/As(V) ratio in the soil was compared with that of a soil solution contacted with the soil determined by HPLC-ICP-MS, showing that As(III) is distributed to water more readily than As(V). The application of the XANES method is important for a better understanding of the behavior of As(III) and As(V) independently in a natural aquifer.
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  • Li-li YANG, Li-rong GAO, De-qiang ZHANG
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 897-902
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    A method has been described for the determination of arsenic species (arsenite and arsenate) by hydride generation-atomic fluorescence spectrometry (HG-AFS). The experimental conditions that influence the fluorescence intensity and the reduction of arsenic were investigated and optimized, and the influences from foreign ions and their elimination were studied. The detection limit was found to be 79.7 ng L-1. The proposed method was applied to the determination of arsenic species in water leachate of traditional Chinese medicines with a recovery range of 91.1 - 109.5%.
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  • Sang Hak LEE, Ming LI, Jung Kee SUH
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 6 Pages 903-906
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    A new chemiluminescence method for the determination of carbamazepine (CBZ) has been developed. The method is based on the chemiluminescence produced in the reaction of tris(2,2′-bipyridine)ruthenium(III) and CBZ in an acidic medium. The chemiluminescence intensity was enhanced by organic solvents in the reaction system. Under the optimum experimental conditions, the calibration curve was linear over the range 4.0 × 10 - 3 - 8.6 × 10-7 mol/L for CBZ. The detection limit (S/N = 3) was 2.5 × 10-7 mol/L and the relative standard deviation of six replicate measurements was 2.6% for 4.0 × 10-4 mol/L of CBZ. The possible reaction mechanism were also discussed. The chemiluminescence method was successfully applied to assay the CBZ contents in pharmaceutical tablets.
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  • Nafisur RAHMAN, Mohammad KASHIF
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 907-911
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    A simple kinetic spectrophotometric method is described for the determination of famotidine. The method is based on the oxidation of the drug with alkaline potassium permanganate. The reaction is followed spectrometrically by measuring the rate of change of the absorbance at 610 nm. The initial-rate and fixed-time (at 12 min) methods are adopted for determining the drug concentration. The calibration graphs are linear in the ranges of 2 - 10 μg mL-1 and 1 - 8 μg mL-1 using the initial-rate and fixed-time methods, respectively. The method has been applied to the determination of famotidine in tablet formulations. The obtained results are compared statistically with those given by a reference spectrophotometric method.
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  • S.S. MITIC, G.Z. MILETIC, D.A. KOSTIC
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 913-916
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    The kinetic method is based on a catalytic effect on the oxidation of sodium pyrogallol-5-sulfonate by hydrogen peroxide. The reaction is followed spectrophotometrically at 436.8 nm. The kinetic parameters of the reaction are reported and a rate equation is suggested. The calibration graph is linear in the range 10 - 200 ng cm-3. The effects of certain foreign ions upon the reaction rate were determined for the assessment of the selectivity of the method. This method has high sensitivity and good selectivity when anions are concerned as well. That is why it can be successfully applied to determination of iodide in real samples (mineral water and soil) directly after the elimination of cations, which interfere. The method was applied to determine iodide in natural waters and soil.
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  • Abbas AFKHAMI, Ali Reza ZAREI
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 917-921
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    The H-point standard addition method (HPSAM) was applied to the simultaneous determination of Bi(III) and Sb(III). This method is based on the difference in the absorbance of complexes of Bi(III) and Sb(III) with iodide in acidic media in different wavelength pairs. The results showed that Bi(III) and Sb(III) can be determined simultaneously with concentration ratios of 15:1 to 1:20. First-derivative spectrophotometry was also used for the simultaneous determination of Bi(III) and Sb(III) based on their complexes with iodide. The proposed methods were successfully applied to the simultaneous determination of Bi(III) and Sb(III) in synthetic samples.
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  • Wei JIANG, Yu FENG, YuDao MA, NaiXing WANG, ZhiKun SI
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 923-925
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    The quadruple complex formed by terbium with 4-chlorosalicylic acid (CSA), EDTA and cetyltrimethylammonium bromide (CTMAB) has been used for the sensitive spectrofluorometric determination of terbium in mixed rare earths. The effect of the experimental conditions on the fluorescence intensity was defined. Under the optimum conditions selected, the fluorescence intensity was linear with the terbium concentration in the range of 3.0 × 10-8 − 1.0 × 10-5 mol/L with a detection limit of 8.0 × 10-9 mol/L (S/N = 3). It has been satisfactory for the determination of terbium in mixed rare earths with good recovery.
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  • Shao-Pu LIU, Xiao-Li HU, Hong-Qun LUO
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 927-932
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    In a weak acid medium, some aminoglycoside antibiotics, such as kanamycin (KANA), gentamicin (GEN), tobramycin (TOB) and neomycin (NEO), or acid bisazo dye Evans Blue (EB) can only produce very weak resonance Rayleigh scattering (RRS) signals. However, when two agents react with each other to form ion-association complexes, the RRS intensity can be greatly enhanced and a new RRS spectrum with a significant enhancement of the RRS intensity in the wavelength range from 350 nm to 600 nm can be observed. The maximum scattering peak is at 570 nm. There is linear relationship between the RRS intensity and the antibiotic concentration in the range of 0.01 - 6.0 μg mL-1 at 570 nm. This RRS method for the determination of aminoglycoside antibiotics at trace-amount levels has been developed. The detection limits (3σ) of the four antibiotics, whose order of sensitivity from high to low ranks as KANA > NEO > TOB > GEN, are 5.2 - 6.9 ng mL-1. This method has good selectivity and has been successfully applied to the quick determination of antibiotics not only for injections and ear drops, but for clinic serum samples as well. In addition, the reaction mechanism by using a quantum chemistry method and the influencing factors of the RRS spectra and the enhancement reasons of RRS have been discussed.
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Notes
Instrumental Achievements
  • Federico MARTÍNEZ RAMOS, Manuel SORIANO-GARCÍA, Gerardo ...
    Type: Others
    Subject area: Others
    2003 Volume 19 Issue 6 Pages 965-966
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    C14H10O2Se2 is monoclinic, P21/c. The unit-cell dimensions at 293 K are a = 12.795(2), b = 12.126(2), c = 9.0179(13)Å, β = 107.074(6)°, V = 1337.5(3)Å3, and Z = 4. The R value is 0.048 for 2319 observed reflections. The dihedral angle between the plane C4-C7(O2)-Se1 and C9-C8(O1)-Se2 is 85.6(2)°, keeping the Se atom unshared electron pairs in a more stable configuration with the rest of the molecule. The packing in the crystal is entirely due to van der Waals forces.
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  • Yung-Chan LIN, Tian-Huey LU, Fen-Ling LIAO, Chung-Sun CHUNG
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 6 Pages 967-968
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    The crystal structure of the title compound, [Ni(C8H20N4)(C12H8N2)](ClO4)2, has been determined by X-ray diffraction. The Ni(II) ion is six coordinated with four nitrogen atoms of the tetradentate macrocyclic ligand and two nitrogen atoms of the bidentate ligand in a distorted octahedron geometry. The folded tetradentate macrocyclic ligand adopts a configuration having four five-membered chelate rings in distorted eclipsed conformations. The four hydrogen atoms of the amine groups of the macrocyclic ligand are on the same side towards the bidentate ligand.
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  • Mehmet KABAK, Vildan GÜNER, Yalçin ELERMAN, Tahsin N. DURL ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 6 Pages 969-970
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    3,3-Dichloro-N-p-methoxyphenyl-4-(2-phenylstryl)-2-azetidinone (C22H15Cl2NO2) was studied by X-Ray analysis, which indicated a monoclinic space group, P21/c, with a = 9.619(5), b = 13.879(4), c = 14.161(5)Å, β = 100.16(3)°, V = 1860.8(13)Å3, Z = 4, Dc = 1.414 g cm-3, μ(Mo Kα) = 0.366 mm-1 and F000 = 816. The structure was solved by direct methods and refined to R = 0.041 for 4026 reflections [I > 2σ(I). The β-lactam ring (2-azetidinone) has antimicrobial affects. The substituents of the methoxyphenyl and phenyl substituents do not change the activity property of the beta-lactam ring, and the activity properties depend on the planarity of the β-lactam ring.
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  • Kanidtha HANSONGNERN, Uraiwan SAETEAW, Golam MOSTAFA, Fen-Ling LIAO, T ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 6 Pages 971-972
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    The title compound, C26H20N6BrRu(BF4), crystallizes in the centrosymmetric space group P21/n and consists of discrete complex units. The Ru(II) ion is octahedrally coordinated to one 2,2′:6′,2″-terpyridine (tpy), one 2-(phenylazo)pyridine (azpy) and a Br atom in trans-axial position at a distance of 2.547(5)Å. The shorter Ru-N (azo) distance (1.960(3)Å) than the Ru-N(py) distance (2.061(3)Å) signifies a strong π-backbonding, which leads to a longer, N=N (azo) bond (1.304(4)Å).
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  • Ichiro TAKAHASHI, Mikio TSUZUKI, Hidehiko KITAJIMA, Minoru HATANAKA, S ...
    Type: scientific monograph
    Subject area: Infomation Science
    2003 Volume 19 Issue 6 Pages 973-974
    Published: 2003
    Released: January 21, 2004
    JOURNALS FREE ACCESS
    The structure of the Diels-Alder cycloadduct formed from 2-(1,2,3-1H-benzotriazol-1-yl)-2-(p-tolyl)-2H-isoindole and dimethyl acetylenedicarboxylate was proved as 11-aza-1-(1,2,3-1H-benzotriazol-1-yl)-11-(4-methylphenyl)-tricyclo-[5.2.1.02,7]undeca-2,4,6,9-tetraene-9,10-dioic acid dimethyl ester. The benzotriazole moiety was located as its 1-yl form, analogous to previous reports. The benzotriazole and the benzene (of tricyclo framework) planes were twisted with an angle of 115.83°. Intramolecular close contacts between benzotriazole and ester are characteristic [N(3)…C(26), 2.754(3)Å; N(3)…H(22), 3.26(4)Å]. The shortest contact of N(3)…H(22) accounting for the rotation of the methyl group is estimated to be 3.10 Å, which might be reasonable as C-H…N-type hydrogen bonding.
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