bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactions of Bis[Diphenyl‐3‐(4‐Methoxyphenylsydnonyl)]Phosphine Palladium Chloride and Phosphorus Ligands and Crystal Analysis of Its Phosphite Adduct
Authors: Lin S. T. , Peng K. J. , Hung T. F. , Tien H. J. 
Published: May 2015

AbstractReactions of bis[diphenyl‐3‐(4‐methoxyphenylsydnonyl)]phosphine palladium chloride and phosphines or phosphites were performed yielding cis‐dichloropalladium complexes. Complexes have been characterized by spectroscopic techniques (compounds 5–13) and by X‐ray diffraction for compound 5. Bond lengths of P‐C(10) and P‐C(16) de creased more than that of P‐C(s) after complex formation suggesting that the phenyl rings were able to contribute more electron density to phosphorus for binding with Pd(II) than the sydnone ring does. The equilibrium constants and rate constants for the reaction between complex 4 and phosphorus ligands depend not only on the basicity but also on steric size (i.e., cone angle) of phosphorus ligands used.
Synthesis and Spectral Properties of Phenyl‐Pyridin‐2‐Ylmethylene‐Amine Complex of Rhodium(III)
Authors: Lee Jen Rong , Lung Jin Wang , Huang Wen Liang 
Published: May 2015

AbstractA new complex of [Rh(PA)2Cl2]Cl·H2O (where PA = phenyl‐pyridin‐2‐ylmethylene‐amine) has been synthesized and characterized. The complex shows high intensity bands in the UV region, and these are assigned to spin‐allowed π‐π* transitions. The medium‐intensity absorption band profile in the lower energy region can be explained by convolution of spin‐allowed CT and d‐d* transitions. Emission spectrum at low temperature (77 K) of the complex in EtOH/MeOH (4:1 v/v) has also been investigated. It shows a broad, symmetric, and structureless red emission with micro second life time and hence is assigned as d‐d* phosphorescence. Voltammetric data have also been obtained for the complex. There were three reduction peaks observed for the complex. The first peak, including two reduction steps with elimination of two chlorides, is consistent with ECEC reaction.
Langmuir Aggregation of Stain on Ionic Surfactant and its Application: Interaction of Bromo‐Pyrogallol Red with Cetyl Trimethylammonium Bromide (CTAB) and Determination of Molybdenum Traces
Authors: Gao Hong‐Wen 
Published: May 2015

AbstractThe microphase adsorption‐spectral correction (MPASC) technique was de scribed and applied to study the interaction of bromo‐pyrogallol red (BPR) with cetyl trimethylammonium bromide (CTAB). The synergism mechanism of micelles was analyzed and discussed. The large electrostatic micelle adsorbs the chromophore in only the monolayer, and the adsorption obeys the Langmuir adsorption. The formation of the (BPR2·CTAB)78 aggregate accelerates the Mo‐BPR complex reaction. Experimental results showed the adsorption constant of the adsorption aggregate 6.20 × 105 and its molar absorptivity ϵr610nm = 1.40 × 106 lmol−1cm−1. For analysis of samples, the recovery of Mo was between 97.4 and 107% and the RSD was less than 4.39%.
Fe(phen)32+‐Modified Zeolite Particles and Their Energetic Studies
Authors: Liou Yea Wenn , Wang Chong Mou 
Published: May 2015

AbstractChemically modified zeolite Y (NaY) particles and their resulting modified electrodes were prepared with acridinium (AcH+), iron(II) and 1,10‐phenanthroline (phen) for energetic studies. According to diffuse reflectance absorption spectroscopy and cyclic voltammetry, AcH+ and Fe(phen)32+ were successfully entrapped in the zeolite particles. Transient emission spectra measurements showed that the life time of AcH+* in the zeolite particles (to 35 ns; λex 365 nm; λem 500 nm) was greatly reduced upon incorporating Fe(phen)32+ and Fe2+. The fast de cay of AcH+*(NaY) suggested that a reductive quench was likely to take place in the zeolite particle. Probably due to a size‐exclusion effect, the bulky electron donor, N, N‐diethyl‐2‐methyl‐1,4‐phenylenediamine (DEPD), revealed a difficulty in reaching the photosensitizer, AcH+, in side the zeolite particle. As a consequence, the in significant photocurrent for the oxidation of DEPD was from the NaY|AcH+ electrode. However, if Fe2+ and Fe(phen)32+ were incorporated, the photocurrent would become more significant. Closer examinations, in addition, showed that the photooxidaton of DEPD occurred more rapidly on the NaY|AcH+|Fe(phen)32+ electrode, compared to the NaY|AcH+|Fe2+ electrode. This difference apparently results from a greater gap in energetics between DEPD and Fe(phen)33+(NaY) than that between DEPD and Fe3+(NaY). Due to this effect, a greater amount of indophenol blue, derived from the coupling reaction of the oxidized DEPD with 1‐naphthol, was formed and de posited on the NaY|AcH+|Fe(phen)32+modified electrode. Thanks to this photo‐induced charge‐transfer reaction, the NaY|AcH+|Fe(phen)32+ particle showed an application potential in image recording.
Reclamation of Used Engine Oil
Authors: Ishaq Mohammad , Iqbal Yousaf , Ahmad Imtiaz , Khan Waqar 
Published: May 2015

AbstractUsed lubricating oil from vehicles was treated with various types of chemicals to be regenerated. It was found that used lubricating oil could be reclaimed with sulphuric acid, sodium hydroxide, sodium phosphate, ammonium sulphate and rosin. Viscosity and pour point of the reclaimed lubricating oil were improved with the additive methyl methacrylate. The reclaimed lubricating oil was characterized by four‐ball ma chine and it was found that wear scar diameter (WSD) has greatly been de creased with the reclamation. The results of atomic absorption spectrophotometer also show that wear metals have also been de creased to an appreciable amount in there claimed lubricating oil.
Non‐Alkaloidal Constituents from the Stem of Ficus Septica
Authors: Kuo Ping‐Chung , Chm Chao‐Chen , Shi Li‐Shian , Li Chia‐Ying , Wu Shwu‐Jen , Damu A. G. , Wu Pei‐Lin , Kuoh Chang‐Sheng , Wu Tian‐Shung 
Published: May 2015

AbstractSeven triterpenes, two lignans, and twelve other known compounds were isolated from the non‐alkaloidal fractions of the stem of Ficus septica Among these triterpenoids, a rare triterpene skeleton derivative, 13,27‐cycloursan‐3β‐ylacetate was isolated from natural sources for the first time. All the structures of these compounds were elucidated by spectroscopic methods.
Immobilized Lipase PS‐C Catalyzed Resolution of Racemic Aromas by Transesterification
Authors: Jagtap Dhananjay V. , Shukla Manojkumar R. , Salunkhe Manikrao M. 
Published: May 2015

AbstractPseudomonas cepacia lipase immobilized on ceramic particles (PS‐C) enantioselectively acylate racemic aroma alcohols with vinyl acetate inorganic solvent. It is observed that laevo isomer under goes enzymatic transesterification enantioselectively.
Bulk Polymerization of Styrene and 4‐Methylstyrene with Cp*Ti(OBu)3/MAO/TIBA Catalyst
Authors: Hong J.‐L. , Chen Y.‐P. 
Published: May 2015

AbstractCopolymerization of different amounts of styrene (St) and 4‐methylstyrene (MSt) using Cp*Ti(OBu)3/MAO/TIBA catalyst was performed in bulk state under hydrogen atmosphere. With out the participation of a reaction solvent, polymerization proceeded well with better yield as compared to those with toluene or cyclohexane as reaction solvent. The sharp peaks in the 13C NMR spectra indicate that both the St and MSt units in the copolymers are co‐syndiotactic in nature. The reactivity ratio evaluated from a Fineman‐Ross plot suggests a better reactivity of MSt than St monomers. Experiments also indicate that the decrease of Mn and Mw, and the broadening of molecular weight distribution were accompanied by the higher hydrogen pressure employed in the polymerization stage, a result attributed to the chain transfer reaction promoted by the hydrogen gas.
Extractive Determination of Vanadium in Fungi Samples
Authors: Kamavisdar Anand , Khanwalkar Shitikanth R. , Patel Rajmani 
Published: May 2015

AbstractA new reagent system has been reported for the extractive separation and simultaneous spectrophotometric de termination of vanadium (V). The method is based on the formation of a water in soluble blue‐violet V(V) complex with N‐hydroxy‐N‐m‐tolyl‐N′‐phenylbenzamidine (HTPBA), and neutral surfactant Triton X‐100 into chloroform over an acidity range of 1.0–10.0 M acetic acid. The complex shows a broad absorption maximum at 570 nm, when measured against a chloroform blank. The λmax (570 nm) of the complex and that of re agent (313 nm) are well separated, hence the excess of the reagent does not interfere in the spectrophotometric de termination of the metal. The molar absorptivity (ϵ) of the complex is (4.74) × 103 1 mol−1 cm−1. The linearity of the calibration curve is followed between 0.5–12.0 μg mL−1 with slope, intercept and correlation coefficient of 9.16× 10−2, 4.5 × 10−3 and 0.999, respectively. The detection limit of the method is 45 μgl−1. The proposed re agent system provides significantly higher tolerance limit for iron (500 μg mL−1) and also various metalions commonly associated with vanadium did not interfere. The method was applied for the deter mi nation of vanadium content of three samples i.e. Spirogyra, Puccinia and Riccia.
On‐Line Determination of Arsenic Species in Sea Water by Selective Hydride Generation Coupled with Inductively Coupled Plasma — Mass Spectrometry
Authors: Den Su‐Jane , Wei Wen‐Chmg , Mierzwa Jerzy , Yang Mo‐Hsiung 
Published: May 2015

AbstractA method for direct de termination of total in organic arsenic (III+V), arsenic (III) and dimethylarsinate (DMA) in sea water was developed by combining continuous‐flow selective hydride generation and inductively coupled plasma mass spectrometry (ICP‐MS) is presented. The principle underlying selective hydride generation is based on proper control of the reaction conditions for achieving separation of the respective arsenic species. The effects of pH and composition of reaction media on mutual interference between the arsenic species were investigated in detail. The results indicate that the appropriate media for the selective determination of total in organic arsenic, DMA and As(III) are 6 M HNO3, acetate buffer at pH = 4.63 and citrate buffer at pH = 6.54, respectively. The concentrations of total inorganic arsenic species, As(III+V), and As(III) were respectively deter mined and that of As(V) was obtained by the difference between them. As to the concentration of DMA, it was obtained after correction from the interference caused by As(III) and As(V). By following the established procedure, the detection lim its (as based on 3‐sigma criterion) for As(III+V), As(III) and DMA were 0.050, 0.009, and 0.002 ng/mL, respectively. There liability of the pro posed method was evaluated in terms of precision and spike addition. The results indicated that the precision of better than 3% and spike recovery of 95 to 105% for all the arsenic species tested in the natural sea water samples can be obtained.
A Simple and Efficient Method for the Synthesis of α,β‐Unsaturated Acyl Azo Compounds with NaNO2‐Acetic Anhydride Under Mild Conditions
Authors: Li Xiao‐Chuan , Wang Yu‐Lu , Wang Jin‐Ye 
Published: May 2015

AbstractIn this paper, eight aryl substituted α, β‐unsaturated acyl hydrazides undergo efficient oxidation to α,β‐unsaturated acyl azo compounds using NaNO2‐acetic anhydride under mild conditions with excellent yields.
Kinetics of the Reaction between Aromatic Aldehydes and 1,5‐Diamino‐4,8‐Dihydroxypyridazino[4,5‐d]Pyridazine
Authors: Medien H. A. A. 
Published: May 2015

AbstractKinetic studies were performed to investigate the mechanism of Schiff base formation in the reaction between aromatic aldehydes and 1,5‐diamino‐4,8‐dihydroxypyridazino[4,5‐d]pyridazine (DDPP). The studies were conducted at different temperatures with ethanol as solvent and acetic acid as catalyst. It is proposed that the first step involves the reaction of the aldehyde with a solvated proton (i.e. specific acid catalysis). Depending on the acidity of the medium, free or mono‐protonated (DDPP) at tacks the carbonyl group to form a carbinol‐amine inter mediate which then de hydrates to form the product. Plot of ΔH# versus ΔS# for the reaction gave a good straight line with isokinetic temperature of 343.15 K. Good linear relationship was obtained from the plot of log k against σ° values. The rate law derived from the proposed mechanism is in agreement with the experimental data and observations. The effects of meta and para substituents of benzaldehyde toward reactivity have been studied.
Recent Advances in Malaria Chemotherapy
Authors: Robert Anne , Dechy‐Cabaret Odile , Cazelles JÉRǑMe , Benoit‐Vical Françoise , Meunier Bernard 
Published: May 2015

AbstractA short review of the currently used antimalarial drugs is reported. The molecular aspects of the different possible mechanisms of action of artemisinin is documented, including recent data on heme alkylation. The preparation and the in vitro antimalarial activity of new modular molecules named “trioxaquines” is also presented.
Preparation and Reactivity of Mo(NCMe)(η2‐C2Ph2)2(η4‐C4Ph4)
Authors: Chang Su‐Chin , Yeh Wen‐Yann , Lee Gene‐Hsiang , Peng Shie‐Ming 
Published: May 2015

AbstractReaction of Mo(CO)(η2‐C2Ph2)2(η4‐C4Ph4) and Me3NO in acetonitrile solvent affords Mo(NCMe)(η2‐C2Ph2)2(η4‐C4Ph4) 1. Compound 1 reacts with trimethylphosphine to produce Mo(PMe3)(η2‐C2Ph2)2(η4‐C4Ph4) 2, or reacts with diphenylacetylene to produce (η5‐C5Ph5)2Mo 3 and Mo(η2‐O2CPh)(η4‐C4Ph4H)(η4‐C4Ph4) 4. The molecular structures of 1, 2 and 4 have been determined by an X‐ray diffraction study.
Reaction Mechanisms of Strontium Ferrites Synthesis
Authors: Saleh Hesham Ibrahim 
Published: May 2015

AbstractThe reactions between strontium and iron nitrates have been studied in an open atmosphere system using three different molar ratios, 1:1 (I), 1:2 (II) and 2:1 (III) at different temperatures as pointed out from the DTA data. The reaction mechanism was discussed based on the chemical composition characterized by means of thermal analysis, X‐ray diffraction patterns, infrared spectra and magnetic susceptibility. It was found that the reaction products depend on both temperature of reaction and the ratio between reactants. The reaction products were found to be composed of a variety of iron compounds that possess different valences: SrFeO2.86, SrFeO2.97, SrFe2O4, SrFe12O19, Sr2Fe2O5 and Sr7Fe10O22 in addition to some accessory reaction products namely α‐Fe2O3 and FeO(OH).
Determination of Naphthalenesulfonate Isomers in Industrial Effluents and River Water by Solid‐Phase Extraction and Capillary Zone Electrophoresis
Authors: Liu Cm‐Hung , Ding Wang‐Hsien 
Published: May 2015

AbstractThis work presents a method to separate polar naphthalenesulfonate (NS) isomers by capillary zone electrophoresis (CZE) with ultraviolet detection in industrial effluents and river water samples. The method involves extraction of samples by a polystyrene‐divinylbenzene copolymer (PS‐DVB) solid‐phase extraction (SPE) cartridge. The most effective CZE separation conditions were obtained in 20 mM borate buffer with 30% acetonitrile at pH 9.0 and 30 °C. The method proposed herein provides a high precision and sensitivity for NS isomers, to quantitation at ≤ 1.0 μg/L in 200 mL of the water samples. Recovery of the NS isomers in spiked water samples ranged from 73% to 87% while RSD ranging from 5.6 to 9.7%. The analysis of industrial effluents and river water samples was performed and naphthalene‐2‐sulfonate was found as a major pollutant. The difficulties in quantitating and identifying analytes in complex environmental samples can be resolved by using an internal standard response factor to calculate concentrations and relative migration times for peak confirmation.
Pictet‐Spengler Condensation of N,N‐Dimethylsulfamoyl‐β‐Phenethylamines with Methylthioacetic Acid Ethyl Ester. New Synthesis of Ethyl 1,2,3,4‐Tetrahydroisoquinoline‐1‐Carboxylates
Authors: Wang Huey‐Min , Su Chien‐Hsing , Kang Iou‐Jmn , Chen Lmg‐Chmg 
Published: May 2015

AbstractThe reaction of N,N‐dimethylsulfamoyl‐β‐phenethylamines with methylthioacetic acid ethyl ester using phenyliodine(III) bis(trifluoroacetate) gives moderate to good yields of the corresponding ethyl 1,2,3,4‐tetrahydroisoquinoline‐1‐carboxylates.
Photocatalytic Acetolysis of α‐Epoxyketones
Authors: Memarian Hamid R. , Nikpour Farzad 
Published: May 2015

AbstractPhotocatalytic ring opening of α‐epoxyketones by 2,4,6‐triphenylpyrylium tetrafluoroborate in glacial acetic acid resulted in the formation of diastereomeric hydroxyester compounds. The presence of the additional substitutent on the parent molecule affects the rate of the ring opening.
A New Redox Reaction of Ascorbic Acid at Platinum Electrodes
Authors: Ye Bao‐Xian , Lin Lin , Wang Cm‐Hong , Jin Bao‐Hm , Liu Ling‐Fang 
Published: May 2015

AbstractA pair of new redox peaks of ascorbic acid at a platinum electrode was found and studied in detailed by spectroelectrochemistry and electrochemistry technologies. This is a quasi‐reversible redox reaction with a one‐electron transfer process. The intermediate of tertiary carbon free radical exists in this process. The appearance reaction rate constant and the diffusion coefficient were investigated. A possible reaction mechanism has been proposed.
Amyloid Structure: Models and Theoretical Considerations in Fibrous Aggregates
Authors: Morgan David M. , Lynn David G. , Lakdawala Ami S. , Snyder James P. , Liotta Dennis C. 
Published: May 2015

AbstractIn celebration of the many contributions to peptide chemistry from K.‐T. Wang's laboratory, this manuscript explores the structure of the Aβ(10–35) fibril. This central segment of the Aβ peptide of Alzheimer's Disease self‐assembles into well‐ordered paracrystalline arrays that seem to contradict many of the accepted paradigms established for soluble, globular proteins. Here we exploit initial molecular modeling efforts to assist in understanding these apparent contradictions. The emerging structure is one of a large self‐assembly of β‐strands, whose stability is dependent on large spatial and temporal fluctuation about a central core, giving rise to what can be best described as a dynamic and fluid tube‐like micelle. This fibril structure maintains features that are distinctly different from those of either synthetic or biological fibrils, and these differences have profound implications for biomedical intervention in amyloid diseases as well as for the design of self‐assembling nanoscale fibrils.
Lithium Hydrides and Lithium Dimers: Sub‐Doppler Spectroscopy and Dynamics
Authors: Bouloufa N. , Cacciani P. , Jeung G.‐H. , Vetter R. 
Published: May 2015

AbstractDeep insights into molecular structures and dynamics were obtained for lithium dimers and lithium hydrides by sub‐Doppler spectroscopy combining molecular beams and cw tunable laser beams. For 7Li7Li species, accurate spectroscopic studies of the B 1Πu‐X 1Σg+ system were carried out, with the measurement of hundreds of wave numbers and with the determination of dissociation rates due to tunneling through the potential barrier of the B 1πu state. They led to the full description of the B state potential, including its barrier. For 6Li7Li species, weak but non‐negligible dissociation rates in the B 1Πu state were observed, measured and interpreted assuming that an electronic coupling between the B 1Πu and 1 1Πg states takes place through an ungerade‐gerade symmetry breaking. For LiH species, the A 1Σ+‐X 1 Σ+ system was revisited for both isotopomers. For this molecule, dynamical effects are predicted in highly‐excited Rydberg states, that could be studied by use of similar sub‐Doppler techniques.
Formation of Alkyne Bridged Multicobalt Carbonyl Complexes with Tris(2‐Thienyl)Phosphine or Bis(Trimethylsilylethynyl)Phenylphosphine Ligand
Authors: Hong Fung‐E , Lien Fang‐Ching , Chang Yu‐Chang , Ko Bao‐Tsan 
Published: May 2015

AbstractTreatment of Co4(CO)12 with an excess of trimethylsilylacetylene (TMSA) in the presence of tri(2‐thienyl)phosphine in THF at 25 °C for 2 hours yielded six compounds. Two pseudo‐octahedral, alkyne‐bridged tetracobalt clusters, [Co4(μ4‐η2‐HC≡CSiMe3)(CO)10(μ‐CO)2] (4) and [Co4(μ4‐η2‐HC≡CSiMe3)‐(CO)9(μ‐CO)2{P(C4H4S)3}] (6), along with an alkyne‐bridged dicobalt complex, [Co2(CO)5(μ‐HC≡CSiMe3)‐{P(C4H4S)3}] (5), were obtained as new compounds. The addition of the thienylphosphine ligand, in fact, facilitates the reaction rate.Reaction of an alkyne‐bridged dicobalt complex, [(η2‐H‐C≡C‐SiMe3)Co2(CO)6] (3), with a bi‐functional ligand, PPh(‐C≡C‐SiMe3)2, yielded an unexpected six‐membered, cyclic compound, {(Ph)(Me3Si‐C≡C)P‐[(η2‐C≡C‐SiMe3)Co2(CO)5]}2 (7).All of these new compounds were characterized by spectroscopic means; the solid‐state structures of (5), (6) and (7) have been established by X‐ray crystallography.
Analysis of Petroleum Distillates from Fire Debris Using Supercritical Fluid Extraction with a Two‐Level Orthogonal Array Experimental Design
Authors: Huang Ching‐Te , Hsieh You‐Zung 
Published: May 2015

AbstractA supercritical fluid extraction (SFE) method was developed in the present study as an effective sample pretreatment technique of petroleum distillates from fire debris. Three petroleum distillates were used as target analytes, including 95 unleaded gasoline, kerosene, and premium diesel. An orthogonal array (L16) experimental design was adopted to separately evaluate primary SFE experimental factors. The SFE efficiencies of petroleum distillates at various extraction conditions were examined and the optimized SFE conditions were identified. Experimental results demonstrated that the optimized SFE method not only provided an effective extraction method for the spiked sample, but also successfully recovered residues of petroleum distillates from fire debris.
Solubilization and Separation of Dicarboxylic Acids by Surfactant Micelles and Polyelectrolytes
Authors: Mahmoud Faten Z. , Youssef Mona I. 
Published: May 2015

AbstractSemi‐equilibrium dialysis (SED) and micellar enhanced ultra filtration (MEUF) methods are used to determine the extent of solubilization of water‐insoluble compounds by surfactant and polyelectrolyte. In this study, solubilization of ortho‐, meta‐ and para‐phthalic acids (OPA, MPA and TPA), 1,4‐ and 2,6‐naphthalene dicarboxylic acids (1,4‐NDCA and 2,6‐NDCA) into hexadecylpyridinium chloride (CPC), and the behavior of these acids to bind to the polyelectrolyte ionizable groups were investigated at 25 °C, using SED and MEUF methods. Polydimethyldiallylammonium chloride (PDMDAAC) is used in this study.It was found that the solubilization of organic acids decreases with increasing the solute mole fractions in micelles. Also, the best separation occurs at the lowest concentration of the phthalate ions and high concentrations of either CPC or PDMDAAC. The results support the idea of charge interaction between the anionic dicarboxylate groups and cationic surfactant or polyelectrolyte. The results also show that the presence of a second phenyl ring does not greatly affect the solubilization behavior of the acids.
Synthesis and Visible Spectral Behaviour of Some New N‐Bridgehead Heterocyclic Cyanine Dyes Incorporating Pyrazolo (4,5‐b) Indolizine (Benzoindolizine)
Authors: Koraiem A. I. M. , El‐Aal R. M. Abd , Mohammed N. S. 
Published: May 2015

AbstractThe new unsymmetrical N‐bridgehead, apo (zeromethine), mono‐methine, dimethine, meso substituted tetramethine and styryl cyanine dyes incorporating pyrazolo (4,5‐b) indolizine (benzoindolizine) nuclei were prepared. Structural confirmation was carried out by elemental analyses, IR, H‐NMR, mass spectra and 13C‐NMR with the aid of carbon DEPT spectral data. The visible absorption spectra for the newly synthesized cyanines were examined in 95% ethanol.