bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aspects of Living Radical Polymerization Mediated by Cobalt Porphyrin Complexes
Authors: Peng Chi‐How , Li Shan , Wayland Bradford B. 
Published: May 2015

AbstractLiving radical polymerization (LRP) of methyl acrylate (MA), acrylic acid (AA), and vinyl acetate (VAc) mediated by cobalt(II) porphyrin complexes ((TMP)CoII·, (TMPS)CoII·) are reported. The polymeric products with relatively low polydispersity and controlled number average molecular weight (Mn) based on one polymer chain per cobalt complex demonstrate the living characters of the polymerization process. The formation of block copolymers of poly(methyl acrylate)‐b‐poly(vinyl acetate) (PMA‐b‐PVAc) and poly(methyl acrylate)‐b‐poly(vinyl pyrrolidone) (PMA‐b‐PVP) demonstrate another important feature of LRP and extend the application of cobalt porphyrin mediated radical polymerization to a wider array of functionalized monomers. Kinetic studies using 1H NMR to follow the formation of orGano‐cobalt complexes reveal that two mechanisms, reversible termination (RT) and degenerative transfer (DT), occur during the polymerization process. MA and VAc polymerization mediated by cobalt porphyrin complexes are used to illustrate the properties of these two LRP pathways and evaluate the kinetic and thermodynamic properties for several of the central reactions.
Water‐Dragging Ability of Aromatic Compounds in Octanol‐Water Systems: A Quantitative Approach by Spectra Deconvolution
Authors: Chang Ya‐Ting , Chang Fang‐Yi , Chen Yi‐Kwan , Lee Ching‐Ju , Yang Chung‐Sung 
Published: May 2015

AbstractThis is the first time that the water‐dragging ability of aromatic compounds partitioning in octanolwater biphasic systems is experimentally estimated by a quantitative spectral deconvolution model. The water‐dragging amount, Δ f value, measured by the quantitative model is based on the integrations of peak area increments of component peaks deconvoluted from O‐H modes of water and octanol molecule, recorded by a Fourier‐transformed infrared spectrophotometer. The stoichiometry hydration capacity, Δ fw, is derived from the corresponding Δ f values. Without any tedious experimental procedure or complicated modeling calculation, the Δ fw value is able to give the required solute‐water hydration information. Such an advantage can't be provided by other techniques applied in the field of water‐dragging ability investigation. Six aromatic compounds were used for the method validation. The Δ fw data obtained by this model are generally consistent with literature‐known values. The efficiency of this quantitative spectral deconvolution model can solve the state of aggregations and the structure of hydrates existing in the organic phase. Moreover, this deconvolution model also has the ability to be extended further to investigate the environmental and biological problems related to the organic chemical portioning in the aqueous and non‐aqueous phases.
Design of an Imipramine‐Selective Electrode Based on an Ion‐Pair and its Application to Pharmaceutical Analysis
Authors: Javanbakht Mehran , Safaraliee Leila , Ganjali Mohammad Reza , Abdouss Majid , Norouzi Parviz , Faridbod Farnoush , Fard Solmaz Eynollahi 
Published: May 2015

AbstractIon‐selective electrodes play an important role in pharmaceutical analysis due to their simplicity, rapidity and accuracy over some other analytical methods. This research introduces the design of an ion‐pair of imipramine‐tetraphenyl borate (IMP‐TPB) based PVC membrane sensor for IMP hydrochloride determination. Effect of the membrane composition, the pH influence and the effect of lipophilic anionic additives on the response characteristics of the electrode were investigated. After a series of experiments, the best electrode performance was accomplished with a membrane composition of 30% PVC, 63% DBP, 5% (IMP‐TPB) and 2% (NaTPB). This electrode illustrated a fast (15 s), stable and Nernstian response across a relatively wide IMP hydrochloride concentration range (10−5 to 10−5 M), in the pH range of (3.0–8.0), and it can be used for at least two months without any measurable change in sensitivity. Additionally, the interference between IMP and several drugs and common inorganic anions was negligible as shown by the potentiometric selectivity coefficient data. The membrane sensor was successfully applied to the determination of IMP in tablets and human urine samples, and very good recovery results were obtained.
Preparation of Tube‐Like ZrO2/NaCl by Microemulsion Method
Authors: Gao Lin , Song Xiu‐Qin 
Published: May 2015

AbstractOn the basis of w/o microemulsion and surfactant template‐assembly technology, tube‐like ZrO2/NaCl was prepared using sodium bicarbonate as precipitant. The w/o microemulsion consisted of a nonionic surfactant OP emulsifier, cosurfactant pentanol and oil hexamethylene alkyl. The morphology, structure, and optical properties of the tube‐like ZrO2/NaCl have been studied by SEM, XRD, FTIR, UV‐vis, and PL techniques.
Effect of Sulfation of Zirconia on Catalytic Performance in the Dehydration of Aliphatic Alcohols
Authors: Hsu Ya‐Sun , Wang Yin‐Lan , Ko An‐Nan 
Published: May 2015

AbstractCatalytic dehydration of 2‐propanol and that of 1‐butanol were performed at atmospheric pressure and 150–300°C over ZrO2 and sulfated ZrO2 (S/ZrO2) in a fixed‐bed, tubular reactor. The catalysts were characterized with XRD, elemental analysis, FT‐IR, N2 physisorption, TG/DTA, TPD, and TPR. The main structures of ZrO2 and S/ZrO2 were monoclinic and tetragonal, respectively. As ZrO2 was modified with sulfuric acid, its surface area and acid amount were greatly increased, whereas the pore volume, the pore diameter, and the particle size were reduced. Both samples owned weak basicity. For both reactions, only dehydration products of alkene and ether were obtained. The alcohol conversion enhanced remarkably with the catalyst acid amount and the surface area as well as the reaction temperature. In addition, the ether selectivity on S/ZrO2 decreased with raising the reaction temperature. The activation energy was 81.0 kJ/mol in the propene formation from 2‐propanol over S/ZrO2. The corresponding value was 94.4 kJ/mol for the dehydration of 1‐butanol.
Capillary Electrophoretic Separation of Tricyclic Antidepressants Using 1‐Alkyl‐3‐Methylimidazolium‐Based Ionic Liquids as Background Electrolyte
Authors: Tsai Chia‐Ying , Yang Ching‐Fei , Whang Chen‐Wen 
Published: May 2015

AbstractA capillary electrophoretic (CE) method coupled with the use of 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (1E‐3MI‐TFB) ionic liquid as background electrolyte (BGE) has been developed for the simultaneous separation of nine tricyclic antidepressants, viz. amitriptyline (Ami), clomipramine (Clo), desipramine (Des), fluphenazine (Flu), imipramine (Imi), nortriptyline (Nor), promazine (Pro), thioridazine (Thi) and trimipramine (Tri). Resolution of TCAs with similar molecular structures and pKa values was accomplished by minute manipulation of the electrophoretic velocities of TCAs via reversed electroosmotic flow (EOF) generated by adsorption of 1E‐3MI cations onto the capillary wall. The optimal separation was obtained with a 50 mM 1E‐3MI‐TFB as the sole BGE at pH 3. Symmetric peaks with efficiencies up to 2.4 × 105 plates/m were achieved. RSD values on migration times and peak areas were in the ranges of 0.63–0.95% and 3.41–6.34% (n = 4), respectively. The role of different alkyl groups on the imidazolium cations was also investigated.
Study on the Binding of Chloride Ion to Hemoglobin Using Electromotive Force Method
Authors: Wang Gong‐Ke , Lu Yan , Yan Chang‐Ling 
Published: May 2015

AbstractThe electromotive force of the concentration cell, in which both half‐cells contain the same concentration of sodium chloride, and one of which also contains hemoglobin (Hb), was measured on the isoelectric point of Hb (pH = 6.70). On the basis of Scatchard equation, a stepwise binding model and an improved calculation method were presented. Using the new calculation method, the number of the chloride‐binding sites on Hb molecule and the corresponding binding constants were calculated. The results show that there are three classes of binding groups on a Hb molecule, the number of the binding sites and the corresponding binding constants are n1 = 1, K01 = 245; n2 = 8, K02 = 3.50; n3 = 8, K03 = 1.91, respectively. The factors of influencing the interaction between Cl− and Hb molecule were clarified, and that the differences between our results and the results of computer modeling, as well as the results of molecular dynamics simulation were also discussed.
Mild Oxidation of Oxime Derivatives with KMnO4 in Ionic Liquid Media
Authors: Safaei‐Ghomi Javad , Hajipour Abdol Reza 
Published: May 2015

AbstractIn this research, potassium permanganate in the presence of a catalytic amount of [bmim]Br under solvent free conditions is used as an efficient and chemoselective method for oxidative cleavage of some oximes to corresponding carbonyl compounds. This experiment was carried out in mild conditions without any further oxidation of aldehydes to corresponding acids.
Nucleophilic Solvent Participation in the Solvolysis of Tertiary Bromoalkanes
Authors: Liu Kwang‐Ting , Hou Su‐Jiun , Tsao Meng‐Lin 
Published: May 2015

AbstractThe solvolysis of 2‐bromo‐2‐methylpropane (1B), 2‐bromo‐2‐methylbutane (2B), 2‐bromo‐2, 3‐di‐methylbutane (3B), 2‐bromo‐2, 3, 3‐trimethylbutane (4B), 3‐bromo‐3‐methylpentane (5B), 3‐bromo‐2, 3‐dimethylpentane (6B), 3‐bromo‐2, 2, 3‐trimethylpentane (7B), 3‐bromo‐3‐ethylpentane (8B), 3‐bromo‐3‐ethyl‐2‐methylpentane (9B) and 2‐bromo‐2, 4, 4‐trimethylpentane (11B) in 15 to 21 solvents was studied, and correlation analyses by using the single‐ and dual‐parameter Grunwald‐Winstein equations (Eqns 1 and 2) were examined. Substrates 7B, 9B and 11B showed excellent linear relationship (R ≥ 0.997) in the logk ‐ YBr plots and indicated limiting SN1 mechanism for the solvolysis. On the other hand, bromides 1B‐6B and 8B gave linear correlations (R = 0.987–0.996) with the dual‐parameter (YBr and NOTs) equation (2) only, which indicated the presence of significant nucleophilic solvent participation. Normal trends of reactivity due to the relief of B‐strain could be found in the poorly nucleophilic trifluoroethanol. Similar to the corresponding chlorides, the overwhelming influence of nucleophilic solvent assistance results in the observed inverse order of reactivity: k(2B) > k(3B), k(5B) > k(6B) and k(8B) > k(9B).
A Mild Method for the Protection of Aldehydes as Dithioacetals and Dithiolanes Catalyzed by I2 Generated in Situ Using Fe(NO3)3.9H2O/NaI Under Heterogeneous Conditions
Authors: Rostami Amin , Nik Heidar Ali Alavi , Roosta Zahra Toodeh , Khazaei Ardeshir 
Published: May 2015

AbstractStructurally diverse aromatic aldehydes were thioacetalated in a clean and efficient reaction with ethane‐1, 2‐dithiol and thiophenol based on the use of I2 generated in situ from Fe(NO3)3.9H2O/NaI. The reaction occurs in good to high yield in dichloromethane at room temperature and the use of toxic and corrosive molecular iodine is avoided.
Computational Study on the Unconventional Hydrogen‐Bonded F–H···C Systems
Authors: Liao Hsin‐Yi 
Published: May 2015

AbstractThe F–H···YZ2 (Y = C, Si, BH, A1H;Z = H, PH3) systems were examined using density functional theory calculations. The main focus of this work is to demonstrate that the chemistry of Y(PH3)2 exhibits a novel feature which is a central Y atom with unexpected high basicity. Further, the hydrogen bond strength can be adjusted by the substitution of H atoms of YH2 by PH3 groups. The FH···C(PH3)2 system has the strongest hydrogen bond interaction, which is larger than a conventional hydrogen bond. In addition to electrostatic interaction, donor‐acceptor interaction also plays an important role in determining the hydrogen bond strength. Therefore, a carbon atom can not only be the hydrogen bond acceptor but also can create an unusual stabilized hydrogen bond complex. Also, X3B–YZ2 (X = H, F; Y = C, Si, BH, A1H;Z = PH3, NH3) systems were examined, and it was found that the bond strength is controlled predominately by the HOMO‐LUMO gap (ΔIP). The smaller the ΔIP, the larger the bond dissociation energy of the B–Y bond. In addition, NH3 is a better electron‐donating group than PH3, and thus forms the strongest donor‐acceptor interaction between X3B and Y(NH3)2.
XANES Spectroscopic Studies of the Phase Transition in Gd2Zr2O7
Authors: Lee Yu‐Hsuen , Chen Jin‐Ming , Lee Jyh‐Fu , Kao Huey‐Chuen I. 
Published: May 2015

AbstractThe structural phase transition from fluorite to pyrochlore and the strength of the coordination bond of Zr–O in Gd2Zr2O7 were investigated by XANES spectra of both O and Zr K‐edge. The energy difference of the O K‐edge absorption spectra at 532 and 536 eV was assigned to the crystal field splitting energy of the 4d orbital (ΔE4d, t2g and eg) of the Zr ion. Also, in the samples prepared at higher temperatures, the 536 eV peak moves slightly to higher energy, whereas the absorption energy of 532 eV peak does not shift. A correlation between ΔE4d and the strength of interaction between Zr (4d) and O (2p) orbitals has been found. Furthermore, two Zr K‐edge absorptions at 18020 and 18030 eV of Gd2Zr2O7 have been observed; the splitting energy (ΔE), peak intensity ratio (I18030/I18020), and FWHM of the first derivative of the absorption curve depend on the preparation temperatures. The effect of crystal symmetry and Zr‐O bonding character on the XANES spectral profile was discussed.
Determination of Silver by Flame Atomic Absorption Spectrometry after Preconcentration on Naphthalene Modified with Dithizone
Authors: Fathi M. R. , Pourreza N. , Purweis S. 
Published: May 2015

AbstractA solid‐phase extraction method for preconcentration of silver and consequent determination by atomic absorption spectrometry is described. The method is based on the adsorption of silver on naphthalene modified with dithizone in a column. The adsorbed silver is eluted from the column with a thiourea solution and determined by flame atomic absorption spectrometry. The adsorption conditions including pH, reagent concentration, eluent volume, flow rate and interfering ions were investigated. The calibration graph was linear in the range 10–1000 ng mL−1 of Ag in the initial solution with r = 0.9998. The limit of detection based on 3Sb was 3.9 ng mL−1. The relative standard deviation for ten replicate measurements of 40 and 600 ng mL−1 of Ag was 4.4% and 0.9%, respectively. The method was applied to the determination of silver in mineral, radiology film and wound dressing samples.
On‐Line Selective Solid‐Phase Extraction of Copper with a Surface Ion Imprinted Silica Gel Sorbent
Authors: Guo Jia‐Jia , Su Qing‐De , Gan Wu‐Er 
Published: May 2015

AbstractCopper(II)‐ion imprinted silica gel (Cu‐IISG) sorbent was synthesized by surface imprinting technique and was employed as a selective solid‐phase extraction material for on‐line preconcentration and separation, then coupled with atomic absorption spectrometry (AAS) determination of Cu(II). The higher selectivity coefficient of Cu‐IISG for Cu(II) in the presence of competitive ions such as Fe(III), Ni(II) and Zn(II) was above 411, which was 35 times of NISG. The static adsorption capacity and dynamic adsorption capacity were 41.11 mg g−1 and 16.20 mg g−1, respectively. The Cu‐IISG offered a fast kinetics for the adsorption and desorption of Cu(II), which can be used for on‐line preconcentration and detection. Two certified reference materials of GBW07301a sediment and GBW07401 soil were analyzed and the determined values were in a good agreement with the certified values. The developed method was also successfully applied to the determination of trace copper in tea leaf with satisfactory results (recovery between 96.3% and 102.3%).
One‐Step Electrodeposited Carbon Nanotube/Zirconia/Myoglobin Film for Direct Electron Transfer and Electrocatalysis
Authors: Qu Song , Pei Su‐Peng , Zhou Shi‐Lin , Gu Ying‐Ying 
Published: May 2015

AbstractA nanobiocomposite film consisted of zirconia, multiwalled carbon nanotubes (MWNTs) and Myoglobin (Mb) was electrochemically deposited on the electrode. Direct electron transfer for the immobilized Mb was realized and high electrocatalytic efficiency toward H2O2 was observed. The proposed biosensor via a simple one‐step electrodeposition method displayed a broader linear range and a lower detection limit for H2O2, as compared with those CNT or ZrO2 based biosensor. The linear range is from 2 × 10−6 M to 1 × 10−3 M with the detection limit of 6 × 10−7 M. The present strategy provides a simple and effective method to assemble CNT, ZrO2 and enzyme nanohybrid on the electrode and expands the scope of CNT‐based electrochemical devices.
Classifying Human Haptoglobin Phenotypes on Native‐PAGE Using a Modified Coomassie Brilliant Blue R 250 Staining
Authors: Liau Chun‐Yi , Ueng Kwo‐Chang , Lin Chung‐Sheng 
Published: May 2015

AbstractThere are three types of human Haptoglobin, Hp 1‐1, Hp 2‐1, and Hp 2‐2, each characterized by a distinct combination of the two α chains of the holoprotein. A modified Coomassie Brilliant Blue R 250 (mCBB‐R250) staining method for detecting the phenotypes of human blood haptoglobin molecules is presented. Addition of excess hemoglobin to the sample allowed specific formation of different haptoglobin‐hemoglobin complexes, which, in turn can be separated into distinctive migration pattern on native‐PAGE and stained by CBB‐R250. The typing results are consistent with that using Western blotting. In comparison to the existing methods for haptoglobin typing, our method is comparable in accuracy, and is easier to carry out. The results on typing of 29 plasma samples from Taipei Blood Center were also presented.
Application of Cloud Point Extraction for Copper, Nickel, Zinc and Iron Ions in Environmental Samples
Authors: Ghaedi Mehrorang , Niknam Khodabakhsh , Niknam Ebrahim , Soylak Mustafa 
Published: May 2015

AbstractA cloud point extraction procedure was presented for the preconcentration of copper, nickel, zinc and iron ions in various samples. After complexation by 2‐(6‐(1H‐benzo[d]imidazol‐2‐yl)pyridin‐2‐yl)‐1H‐benzo[d]Imidazole (BIYPYBI), analyte ions are quantitatively extracted in Triton X‐114 following centrifugation. 1.0 mol L−1 HNO3 nitric acid in methanol was added to the surfactant‐rich phase prior to its analysis by flame atomic absorption spectrometry (FAAS). The adopted concentrations for BIYPYBI, Triton X‐114 and HNO3 and bath temperature, centrifuge rate and time were optimized. Detection limits for Cu2+, Fe3+, Zn2+ and Ni2+ ions was 1.4, 2.2, 1.0 and 1.9 ng mL−1, respectively. The preconcentration factors for all ions was 30, while the enrichment factor of Cu2+, Fe3+, Zn2+ and Ni2+ ions was 35, 25, 39 and 30, respectively. The proposed procedure was applied to the analysis of real samples.
Polar Constituents from Sageretia Thea Leaf Characterized by HPLC‐SPE‐NMR Assisted Approaches
Authors: Shen Ca‐Jane , Chen Chien‐Kuang , Lee Shoei‐Sheng 
Published: May 2015

AbstractNine glycosides (1–9) were characterized from the n‐butanol‐soluble fraction of the ethanolic extract of the leaves of Sageretia thea by the general approach. Among these, Compounds 6 and 7 were identified as a mixture. Application of HPLC‐SPE‐NMR in two selected fractions led to the separation of this mixture and the characterization of three additional minors (10–12). Among these, 7‐O‐methylmyricetin 3‐O‐α‐l‐arabinofuranoside (8) is a new natural product and eight compounds, i.e. glucofragulin A (1), quercetin‐3‐O‐α‐l‐arabinopyranoside (5), 3‐O‐β‐d‐galactopyranoside (6), 3‐O‐β‐d‐glucopyranoside (7), and 3‐O‐α‐l‐arabinofuranoside (11), myricetin‐3‐O‐α‐l‐arabinofuranoside (9) and 3‐O‐β‐d‐glucopyranoside (10), and quercetrin (12), are found for the first time from the title plant.
Synthesis of Glucosylguanidinohydrazones under Microwave Promotion and Ultrasound Irradiation
Authors: Chen Hong‐Mei , Cao Ling‐Hua 
Published: May 2015

AbstractGuanylhydrazone derivatives were obtained by the condensation of glucosylated aminoguanidines with 3‐formylchromones in refluxing THF. Target compounds were synthesized by conventional method, microwave promotion and ultrasound irradiation methods. The structure of all new compounds was confirmed by IR, 1H NMR, 13C NMR spectral data and elemental analyses.
Reusable and Efficient Cul/TBAB‐Catalyzed Iodination of Terminal Alkynes in Water under Air
Authors: Chen Shao‐Nung , Hung Tzu‐Ting , Lin Tze‐Chiao , Tsai Fu‐Yu 
Published: May 2015

AbstractAn environmentally‐friendly and operationally‐simple process for the synthesis of 1‐iodoalk‐1‐ynes under mild conditions catalyzed by CuI/TBAB in water under air was developed in this study. Catalyst loadings of CuI as low as 1–2 mol% gave 1‐iodoalk‐1‐ynes in good to high yields, and the residual aqueous solution after extraction with hexane could be reused for the next reaction without any treatment.
Photocatalytic Degradation of Ethyl tert‐Butyl Ether in Aqueous Solution Mediated by TiO2 Suspensions: Parameter and Reaction Pathway Investigations
Authors: Lu Chung‐Shin , Chiang Tien‐Yu 
Published: May 2015

AbstractDegradation of ethyl tert‐butyl ether (ETBE) with UV/TiO2 was studied by solid‐phase microextraction and gas chromatography‐mass spectrometry. The complete removal of 0.1 g L−1 of ETBE was achieved after 20 h of treatment. Factors such as pH of the system, catalyst and substrate concentration, and the presence of anions influenced the degradation rate. Establishment of the degradation pathway was made possible by a thorough analysis of the reaction mixture, which identified the main intermediate products generated. The possible degradation pathways were proposed and discussed in this research. The attack on the C–H bond in ETBE by ·OH forms an alkyl radical, which consequently produces a peroxyl radical upon reaction with oxygen. Peroxyl radicals react with one another and produce an alkoxy radical. The β‐bond fragmentation of the alkoxy radical produces different intermediates.
Carbon Nanotubes Coated Fiber for Solid‐Phase Microextraction of Bovine Fibrinogen and Bovine Serum Albumin
Authors: Tang Ping‐Ping , Cai Ji‐Bao , Su Qing‐De 
Published: May 2015

AbstractCarbon nanotubes (CNTs) are a kind of novel and interesting carbon material which can be used for separation and purification. In this investigation, commercial solid‐phase microextraction (SPME) fibers (PDMS) were coated with single‐wall nanotubes (SWNTs) and multi‐wall nanotubes (MWNTs) to study their adsorption and extraction ability of proteins, and bovine fibrinogen (BFg) and bovine serum albumin (BSA) were selected as the target proteins. While MWNTs adsorbed more BFg than SWNTs, SWNTs adsorbed more BSA than MWNTs. CNTs can selectively adsorb BFg in certain conditions. The fibers coated with CNTs had advantages over traditional SPME fibers in selectivity and sensitivity. It could be used to separate BFg in bovine blood plasma and also purify BFg from it. The results show that the selectivity, sensitivity and reproducibility of this method are good for real sample analysis.