bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photochemical Reaction of Decacarbonyldirhenium with Thiophene and Crystal Structure of Tetradecacarbonylhydridotrirhenium
Authors: Yang C.S. , Cheng C.P. , Guo L.W. , Wang Y. 
Published: June 2015

AbstractThe photochemical reaction of Re2(CO)10 with thiophene in hexane solution was investigated under vacuum. Three rhenium clusters: H2Re3(CO)12, HRe3(CO)14 and Re3(CO)14(OH)4, were isolated. The structure of Fellmann‐Kaesz cluster Complex HRe3(CO)14 was determined by use of the X‐ray diffraction method. The three rhenium atoms form a plane of symmetry and L: Re1Re2Re3 is 107°. The ten carbonyl groups bonded to the two terminal rhenium atoms Re1 and Re3, are staggered with respect to the central rhenium atoms. The bond lengths are 3.10 Å for Re2‐Re3 and 3.34 Å for Re1‐Re2. The bridging hydride is between Re1 and Re2.
Cobalt (II) Complexes with Tri‐ and Tetradentate Schiff Bases Derived From 2‐Furyl Glyoxal and Some Amines
Authors: Dhakarey Rajesh , Saxena Greesh 
Published: June 2015

AbstractCoordination compounds of cobalt (II) with four new schiff bases of furyl glyoxal, 2‐furyl‐methyl‐2′‐carboxylato ketoanil (2 FMCKA), 2‐furyl glyoxal ethyenediimine (2 FGED), 2‐furyl giyoxal‐2′‐sulphonic acid anil (2 FGSAA) and 2‐furyl glyoxal‐2′‐chloro‐4‐nitro anilimimine (2 FGCNA) were prepared and characterised with the help of elemental analyses, magnetic measurements, infra‐red and electonic spectral data. Various ligand field parameters such as 10 Dq, B & C, F2 & F4, f2 & f4, h, B° etc. and transition energies ν1;, ν2 & ν3, were calculated with the help of electronic spectral data. The ν(C=N) bands in the IR spectra of all the ligands are lowered in complexation indicating nitrogen coordination of the ligands. All these studies indicate that cobalt(II) ion is in a distorted octahedral environment.
A Simple Novel Method for the Analysis of Lubricating Oil Additives by the Use of Sep‐Pak Cartridges
Authors: Wu Yi‐Shuen , Yang Mei‐Hui , Lin Ching‐Erh 
Published: June 2015

AbstractIn combination with the use of SEP‐PAK cartridges and computerized difference infrared spectroscopic technique, a simple novel method for analyzing lubricating oil additives was developed. The present method involves solvent extraction and the use of SEP‐PAK C18 for separating polar additives from residual base oil, followed by the use of SEP‐PAK Silica for further elution. With the aid of infrared data station, components of the polar additives were identified. The present method is definitely much more rapid and efficient than the conventional column separation method, and the separation efficiency of this simple method is comparable to that of using flash chromatographic technique.
A Study of the Constituents of the Heartwood of Tsuga Chinensis Pritz. Var. Formosana (Hay.)
Authors: Fang Jim‐Min , Wei Kuo‐Min , Cheng Yu‐Shia 
Published: June 2015

AbstractBy means of spectroscopic analysis, X‐ray crystallography and chemical correlation the heartwood of Taiwan hemlock was found to contain compounds of sterols, carboxylic acids, 13‐epimanool, o methoxyphenolics, coniferaldehyde, benzofuranoid neolignan, α‐conidendrin, tsugacetal, isolariciresinol, secoisolariciresinol, matairesinol, hydroxymatairesinol and oxomatairesinol. Among them (+)‐tsugacetal is a novel lignan acetal having an α‐conidendrin related structure with the acetal methoxy group at the β‐position.
A New Lignan, Cagayanin, from Nutmeg of Myristica Cagayanensis Merr
Authors: Kuo Yueh‐Hsiung , Wu Rong‐En 
Published: June 2015

AbstractA new lignan, cagayanin, has been isolated from the nutmeg of Myristica cagayanensis Merr. and elucidated as formula (5) by spectral and chemical evidence.
Thermal Diffusion with Chemical Reaction: A Carrier System
Authors: Mou Chung Yuan , Lin Jeong‐Long 
Published: June 2015

AbstractThe heat of transport of oxygen across a membrane mediated by hemoglobin (Hb) as a carrier is iuvestigated by the method of irreversible thermodynamics. It is assumed that oxygen combines with hemoglobin molecules to form oxyhemoglobin according to the reaction nO2 + Hb=HbOzn. The oxyhemoglobin molecule HbOzn then migrates to a new position and is reconverted to Hb by releasing oxygen.It is shown that the heat of transport of oxygen consists of two contributions; one due to the reaction and the other from thermal diffusion of individual species present. Total oxygen flux across the membrane is also calculated in terms of temperature and the chemical potential difference of oxygen across the membrane. The use of the heat of transport as a measure of the efficiency of the heat pump for the carrier‐mediated transport process is investigated.
Stabilities and Thermodynamic Properties of Ethylenediamine‐di(o‐Hydroxyphenylacetic Acid) Chelates of Tripositive Lanthanide Ions
Authors: Hseu Tong‐Ming , Wu Shwu‐Tzy , Lin Zui‐Feng 
Published: June 2015

AbstractThe interaction between ethylenediamine‐di(o‐hydroxyphenylacetic acid) (EDDHA, H4Z) and tripositive lanthanide ions has been investigated. The formation constants of the protonated chelates (LnHZ) and those of the normal chelates (LnZ−) have been evaluated at various temperatures and at a constant ionic strength of 0.1(KNO1). For LnHZ, the pH‐titrimetric technique, and for LnZ−, the mercury indicator electrode method were used. The enthalpy and entropy changes characterizing the formation of LnZ− have been calculated at 25° and, these functions have been compared with the corresponding values of other lanthanide chelates with related chelating agents.
The Reaction of Triplet State Benzophenone with Acetylacetone
Authors: Chow Yuan L. , Buono‐Core Gonzalo E. 
Published: June 2015

AbstractIrradiation of benzophenone in acetic acid containing acetylacetone resulted in regiospecific addition to form cis‐2,2‐dihpenyl‐3‐hydroxy‐3‐methyl‐4‐acetyloxetane and the rearrangement products therefrom. In the co‐presence of copper ions, the regiospecificity is scrambled to give these products and a small amount of 1,1‐diphenyl‐1‐buten‐3‐one, the secondary decomposition product of the other oxetane arising from the alternative orientation of the addition.
A Study of the Slow Release of Urea from Microcapsules with TDI as the Wall‐Sealing Treatment
Authors: Wu Jen Chin , Lin Yih Tsung 
Published: June 2015

AbstractThe release of urea from ethylcellulose coated microcapsules was efficiently reduced by post‐treatment with toluene‐2,4‐diisocyanate (TDI) in n‐hexane. Our results show that TDI can be used as a sealant which modifies the shell characteristics of the ethylcellulose film. The modification is rather complicated in that it probably includes cross‐linking between ethylcellulose and TDI, a reaction between urea and TDI, and biuret or polyurea formation from TDI absorbed on the microcapsules surface with moisture. The influence of post‐treated conditions on the release of urea from ethylcellulose shell was studied.
The Simultaneous Determination of Trace Dy, Eu, Gd and Sm in Nuclear Grade Uranium Oxide by Inductively Coupled Plasma‐Atomic Emission Spectrometry (ICP‐AES)
Authors: Wu Cheng‐I , Chang Fu‐Chung , Wang Shieh‐Jun 
Published: June 2015

AbstractA method for the simultaneous determination of trace Dy, Eu, Gd and Sm in nuclear grade uranium oxide by Inductively Coupled Plasma Atomic Emission Spectrometry has been developed. The process of uranium extraction and ICP/AES optimization are investigated. The detection limits of Dy, Eu, Gd and Sm are 0.003, 0.002, 0.006 and 0.010 μg/ml respectively, and more than 90% recovery can be obtained.
Sydnone Compounds XXX. The Syntheses and Reactions of 3‐Aryl‐4‐Cyanosydnones and 3‐Aryl‐4‐Formylsydnone Oximes
Authors: Yeh Mou‐Yung , Tien Hsien‐Ju 
Published: June 2015

AbstractIn the presence of pyridine, 3‐aryl‐4‐formylsydnone (II) reacts with hydroxyl‐amine hydrochloride to produce 3‐aryl‐4‐formylsydnone oxime (III). This reaction was performed in ethanol solution with reflux or at room temperature; the latter procedure gave an excellent yield (74‐98%) and high purity.(III) reacts in acetic anhydride at room temperature to give 3‐aryl‐4‐formylsydnone oxime O‐acetate (IV).A convenient method for the synthesis of 3‐aryl‐4‐cyanosydnone (V) is to dehydrate (III) with acetic anhydride at reflux. When (IV) was refluxed with acetic anhydride, (V) was similarly obtained. Another convenient method to prepare (V) from (III), dehydration with thionyl chloride at room temperature, was also investigated.
Conformational Studies on Polytripeptides as a Model of Collagen
Authors: Kawai Tohru , Toba Shigeru , Ebert Gotthold , Chang Teh‐Chou 
Published: June 2015

AbstractTo study the role of glycine residues in stabilizing the collagen triple helix, the glycine residues in the polytripeptide (Pro‐Ala‐Gly)n were partially replaced by alanine. The proline content was kept constant. The stability of the helical conformation of these polypeptides was studied by IR‐ and X‐ray measurements in the solid state and by ORD, CD and viscometry in solution. The renaturation was followed as a function of time. All the polytripeptides studied, with the exception of (‐Pro‐Ala‐Ala‐)n attained the polyproline II conformation. However the stability decreased with increasing alanine content. Obviously the molecules of (‐Pro‐Ala‐Gly‐) are highly associated by intermolecular hydrogen bonds and one may therefore suppose that a triple‐stranded helix aggregation occurs. The results of the refolding process show that the stability of the helices seems to also affect the refolding rate in terms of the optical rotation, Two transitions appeared: the first one is responsible for a rapid reversible change in conformation and the second one for a further slow and irreversible change in the hydrodynamic shape. The latter seems to be due to the partial helical nature, leading to higher chain mobility.
Matrix‐Assisted in‐Beam Mass Spectra of Thermally Fragile Molecules
Authors: Liu Lilian Kao , Hsieh Tsing‐Pai 
Published: June 2015

AbstractIn‐beam and matrix‐isolation techniques have been used in the mass spectral studies of several categories of biologically significant compounds. These include amino acids, quaternary ammonium salts, vitamins and nucleosides. Molecular ions and/or (M+H)+ions are obtained, together with useful fragmentations, all of which are valuable in structural elucidations. Spectra obtained by this version of the in‐beam technique are similar but not identical with those obtained by field desorption and secondary ion mass spectrometry. Ammonium and sodium chlorides, ammonium sulfate, p‐toluenesulfonic and hydrochloric acids can all be used as a room temperature matrix. The detection limits for vitamin E and 2′‐deoxyguanosine have been determined as 1 ngand 5 μg, respectively.
A Theoretical Analysis of Single Drop Square‐Wave Polarography
Authors: Hwang Jin‐Yih , Wang Yung‐Yun , Wan Chi‐Chao 
Published: June 2015

AbstractThe peak current response to single drop square‐wave polarography (SDSWP) is developed based on a spherical diffusion model. It is found that the equation originally developed by Ramaley et al. based on a planar diffusion model is only a special case of the generalized model.
Spectrophotometry Determination of Copper and Palladium Using Some 1,3,5‐Triphenylformazans
Authors: El‐Ansary A. L. , Issa Y. M. , Hanna Z. F. 
Published: June 2015

AbstractA new rapid and accurate method for the spectrophotometric microdetermination of Cu(II) and Pd(II) using some 1,3,5‐triphenylformazans (I) is given. The optimum conditions for the formation of the complexes are extensively investigated. The ligands form 1:1 and 1:2 (M:L) complexes with Cu and Pd ions, Beer's law is obeyed up to 3.8 and 6.5 ppm Cu and Pd respectively. The influence of foreign ions is investigated. The ligands were used successfully as indicators in spectrophotometric titration of Cu and Pd ions with EDTA and CDTA.
Syntheses and Diel‐Alder Reactions of Bis(Alkylidene)Cyclohexanes
Authors: Tso Hsi‐Hwa , Liu Lee‐Tai , Lin Lung Chin , Chou Ta‐Shue 
Published: June 2015

AbstractSubstituted cyclohexene‐fused 3‐sulfolenes have been prepared by the direct deprotonation/alkylation reactions of a readily available starting material. These fused 3‐sulfolenes undergo inter‐ and intramolecular Diels‐Alder reactions at high temperatures to give properly substituted bi‐ and tricyclic molecules.
Transition Metal Complexes of an Antipyrine Derivative
Authors: Shoukry Mohamed M. , Elmoghayar Mohamed R. H. , Ibraim Mohamed K. A. , Elghandour Ahmed H. H. 
Published: June 2015

AbstractThe stepwise formation constants of N‐antipyrinyl‐N′‐3‐phenyl‐2‐propenoyl‐thiourea (I) complexes with metal ions of the first transition series, Cu(II), Ni(II), Co(II), Mn(II) and Zn(II) have been determined in 70% (V/V) ethanol‐water medium. The formation constants for the chelates follow the Irving‐Williams series:Zn(II)<Cu(II)>Ni(II)>Co(II)>Mn(II)The effect of ionic radius and electronegativity on the chelate formation are discussed. Complexes of Cu(II) and Ni(II) have been synthesised and characterised by elemental analysis, electrolytic conductance, IR spectra and magnetic susceptibility measurements. The ligand forms bis‐complexes with Cu(II) and Ni(II). The binding sites are oxygen and sulphur atoms.
The Reduction and Nitration of 1‐Keto and 4‐Keto‐1,2,3,4‐Tetrahydrophenanthrene
Authors: Zee Sheng‐Hsu , Lu Chin‐Kun 
Published: June 2015

AbstractThe reduction and nitration of 1‐keto and 4‐keto‐1,2,3,4‐tetrahydrophenanthrene were investigated. The structures of the products were confirmed by spectroscopic data.
Effect of Structure on Excess Partial Volumes and Deviation in Molar Viscosity of Some Aqueous‐Ethylene Glycols Mono Alkyl Ether
Authors: El‐Harakany A. A. , Hafez Amina M. , El‐Laboudy A. S. 
Published: June 2015

AbstractThe data obtained for density, viscosity, and dielectric constant are used for the study of the physical properties of 2‐ethoxy ethanol‐water mixtures. Density measurements showed the presence of contraction in the volume of the mixture and also in the partial molal volume of the components. Viscosity data provided supporting evidence of interaction between the two solvents. The dielectric data for the system were studied in terms of a deviation fraction, δD, representing the deviation from an ideal volume mixture. The results are also compared with the data obtained in the literature for water‐2‐methoxy ethanol and water‐ethylene glycol mixtures.
The Synthesis of p‐Methoxybenzyloxycarbonyl Amino Acids
Authors: Chen Shui‐Tein , Weng Chih‐Shyong , Wang Kung‐Tsung 
Published: June 2015

Abstracto‐Chlorobenzyloxycarbonylimino‐2‐phenylacetonitrile (Cl‐Z‐ON) and p‐methoxybenzyloxycarbonylimino‐2‐phenylacetonitrile (MOZ‐ON) have been prepared from 2‐hydroxyimino‐2‐phenylacetonitrile (oxime), phosgene, and the corresponding alcohols. Cl‐Z‐ON is synthesized for the first time and found to be stable at room temperature. MOZ‐ON is utilized for the preparation of MOZ‐amino acids under various conditions. The oxime can be recovered and reused. The combination of Cl‐Z‐ and MOZ‐ for the alternative masking of the N4‐ and N4‐amino groups of lysine residue has also been studied.
Five New Sesquiterpenes from the Heartwood of Juniperus Squamata Lamb
Authors: Kuo Yueh‐Hsiung , Yang I‐Chang , Chen Chun‐Shing , Lin Yau‐Tang 
Published: June 2015

AbstractExtracts of the heartwood of Juniperus squamata Lamb. var. morrisonicola (Hay.) Li and Keng contain the known constituents 8,14‐cedranoxide, 8,14‐cedranolide, cedrol, β‐sitosterol, widdrol, 7‐oxototarol, procerin, 8,14‐cedranediol, hinokiol, sugiol, hinokiic acid, cedrolic acid, and five new sesquiterpenoids, epicedranediol, 4‐ketocedrol, 3β‐hydroxycedrol, isocedrolic acid, and β‐chamigrenic acid. These new sesquiterpenes were identified by spectroscopic data and chemical correlations.
The Stabilities and Thermodynamic Properties of Triethylenetetraminehexaacetic Acid Chelates of the Tripositive Lanthanide Ions
Authors: Hseu Tong‐Ming , Chang Chun‐Chih , Lin Zui‐Feng 
Published: June 2015

AbstractThe interaction between the decadentate ligand triethylenetetraminehexaacetic acid (TTHA or H6Z) and tripositive rare‐earth metal ions (Ln3+) has been investigated. The acid formation constants of the hydrogen chelates (LnHZ2−, LnH2Z‐) and the formation constants of the normal chelates (LnZ3−) have been evaluated at 15, 25 and 35°C, and at an ionic strength of 0.1 (KNO3), the former by a titration method and the latter by a mercury indicator electrode technique. Enthalpy and entropy changes characterizing the formation of the normal chelates have been calculated at 25°C. These functions have been compared with corresponding values for related chelating agents.
The Chemical Constituents of the Liverwort Mylia Nuda
Authors: Wu Chia‐Li , Asakawa Yoshinori 
Published: June 2015

AbstractTwo diterpenoids, (+)‐labda‐7,14‐dien‐13‐ol and (+)‐manoyl oxide, and one bis(bibenzyl) compound, isomarchantin C, were isolated as the major components from the Taiwanese liverwort Mylia nuda. The spectral evidence is discussed in this paper. In addition, several monoterpenes and sesquiterpenes were also identified by GC/MS.
Characterization of Hydrogen Adsorption on Palladium and Pd/c Using a Radiotracer
Authors: Loh Kuo‐Liang , Tang Yi‐Noo 
Published: June 2015

AbstractHydrogen adsorption on palladium black and palladium supported on activated carbon was characterized by the Temperature Programmed Desorption technique (TPD) using the radiotracer tritium. It is shown that there are five energetic desorbed hydrogens with peak maxima at —50, 35, 115, 350, and 580°C. An additional peak at — 120°C hydrogen desorbed from activated carbon was observed on Pd/C. An isotopic hydrogen separation experiment was designed to demonstrate that hydrogen only dissociatively adsorbed on palladium surfaces whereas it was associatively adsorbed on activated carbon.
Polarization Resistance Study on Copper Corrosion in Aqueous Potassium Hydrogen Phthalate Solution
Authors: Mouhad M. Y. , Bekheet A. M. , Soliman S. A. 
Published: June 2015

AbstractThe effect of temperature on corrosion of copper in 0.1 M aqueous solution of potassium hydrogen phthalate (KHPh) has been investigated using polarization resistance technique. it was found that that the corrosion rate in the range 25–65°C obyes Vant Hoff's and Arrhenius Laws. The results indicate that corrosion of copper in KHPh is mainly cathodically controlled process. The polarization resistance decreases with rising the temperature in accordance with Stern‐Geary equation.
Foam Separation of Stannous Ion from Aqueous Solution
Authors: Ferng Tian‐Fwn , Tzuoo Jong‐Jonq , Huang Shang‐Da 
Published: June 2015

AbstractSn(II) was removed from solution using various foam separation techniques. It was found that Sn(II) could be effectively removed by adsorbing colloid flotation using either Fe(OH)3 or Al(OH)3 as the adsorbing colloid. Over 99% of the Sn(II) was removed from a solution initially containing 50 ppm Sn(II).
Polarographic Studies of Dithiodiacetic Acid and the Uranyl‐Dithiodiacetic Acid Complex
Authors: Kao Chen‐Feng , Chang Tsong‐Dsu , Lai Tsai‐Teh 
Published: June 2015

AbstractThe polarographic behaviour of dithiodiacetic acid and that of U(VI) in a solution containing dithiodiacetic acid as complexing agent have been investigated.For the dithiodiacetic acid system, two waves appear over the pH range studied. The prewave is kinetic in nature and the mainwave is diffusion‐controlled. However, as U(VI) is added into the dithiodiacetic acid system, the polarogram changes due to the existence of a complex. The current‐potential curve of the first wave is not the normal S shape. This is due to the superposition of the first wave of the ligand and the wave due to the reduction of the U(VI) in the complex to U(V). The second wave is due to the reduction of the complex The first wave is an adsorption‐controlled current and the second wave is partly diffusion‐controlled and partly adsorption‐controlled.We propose an electrode reaction mechanism for both systems and the complex species. The dissociation constant of the complex HASSAUO+2 is found to be of the order of 10−4.
Polycyclic Aromatic Hydrocarbons Formation from Fuel and Additives Combustion
Authors: Sye Wen‐Fa , Lin Chyi‐Lian , Yen Ding‐Ping , Tsai Chang‐Shou 
Published: June 2015

AbstractA study has been made of the effect of additives to the fuel of a turbulent diffusion flame on the formation of soot and polycyclic aromatic hydrocarbons (PAHs). Fuels containing a polystyrene thickener doped with benzene proved to have many advantages over unthickened fuels. Most significant were an increase in the burning time and the flash point. Nevertheless, polystyrene and benzene additives to a considerable extent increased the formation of soot and PAHs. The analysis of PAHs in this study was made by capillary gas chromatography (GC) and capillary gas chromatography/mass spectrometry (GC/MS). A total of 42 individual compounds were characterized by their retention indices and mass spectra.
The Polarographic Behaviour of Bromate Ions in Buffered and Unbuffered Solutions and the Effect of Surface Active Substances
Authors: Kamal M. M. , Temerk Y. M. , Ahmed M. E. 
Published: June 2015

AbstractThe polarographic behaviour of bromate ions in buffered and unbuffered solutions has been studied in the absence and presence of cationic, anionic and nonionic surfactants. The mechanism for the reduction in acid media is discussed. The adsorption effects of electrochemically inactive surfactants on the polarographic waves of BrO3− has been investigated. The values of the kinetic parameters for the electrode reaction at different pH values have been computed.
Kinetic Study of the Substitution Reactions of Benzyl Halides and Halide Ions in Acetone
Authors: Lin Szu‐Ning , Jwo Jing‐Jer 
Published: June 2015

AbstractThe kinetics of the Finkelstein reactions of benzyl halides and halide ions in dry acetone was studied by using the GC and HPLC methods. The method of conductivity is used to measure the degree of dissociation of alkali halide in acetone. The dissociation of the salt and the common‐ion effect were used to correct the halide ion concentration. Let kxx′‐ and Kxx′‐ represent the corrected second‐order rate constant and equilibrium constant for the PhCH2X‐X′‐ reaction, respectively, then at 25° kxx‐−= 1.83x×10−3 M−1 s−1, KII‐=4.48×104, kBrcl‐=0.377 M−1 s−1, KBrcl‐=874; and kBr‐=7.88 M−1 s−1, KIBr‐=19.2. The entropy of activation is always negative which implies that the activated complex is more solvated than the reactants. There is a good correlation between the enthalpy of activation and the C‐X bond energy. The enthalpy of activation is much smaller than the corresponding C‐X bond energy which implies that both the bond formation and the bond dissociation are taking place simultaneously in the transition state. A modified Taft equation is used to correlate the Finkelstein reactions of alkyl halides (RCH2X). However, the benzyl halides can not be fit by the correlation equation due to the strong electrical polar effects. Discussion of the Finkelstein reactions of organic halides in terms of rate constants, equilibrium constants, solvent effects, and the thermodynamic parameters is also presented.
Synthesis and Surface Acidity of Alpo4–5 and Sapo–5 Molecular Sieves
Authors: Yang Sze‐Ming , Wu Shiaw‐Tzong 
Published: June 2015

AbstractAluminophosphate molecular sieves, AlPO4 − 5 and SAPO−5, were synthesized and characterized by XRD, SEM, 29Si and 13C NMR, and TGA. Ammonia TPD indicates the moderately acidic nature of SAPO−5 and the non‐acidic nature of AlPO4−5. The activity of the cumene cracking reaction at 350°C for SAPO−5 is similar to that of LaY, while AlPO4−5 and amorphous AlPO4 show no activity.