bluuebunny/crossref_metadata_2025 huggingface dataset:
Selectivity in the Phase Transfer Catalytic Hydrogenation of Nitrobenzene by Transition VIII Metals
Authors: Juang Tzouh‐Miin , Hwang Jeng‐Chai , Ho Hsiu‐O , Chen Chau‐Yang
Published: June 2015

The phase transfer hydrogenation of nitrobenzene to p‐aminophenol has been investigated for the catalysts Pt, Pd, Rh and Ru. The influence of factors such as surfactant concentration, sulfuric acid concentration, hydrogen pressure and temperature on the reaction was determined. It was found that the rate‐determining step for the catalytic hydrogenation of nitrobenzene is the catalytic process by which the hydrogen atom is absorbed on the metal surface. A reaction model is suggested which accounts for the observed hydrogenation selectivity and explains how these factors affect product composition and yield. It is shown that Pt favors p‐aminophenol production, while Pd favors aniline production.
A Study of Monodispersed Polydimethylsiloxanes
Authors: Yang M.H. , Liaw W.C.
Published: June 2015

A series of monodispersed polydimenthylsiloxanes (PDMS) with molecular weights from 3K to 156K were synthesized. The intrinsic viscosity and absolute molecular weight of each monodispersed PDMS was measured and the Mark‐Houwink equation for the PDMS series in toluene at 25°C was derived: [eta;]=2.88 × 10−4 M0.613. It was proven that the accurate molecular weight determination of polysiloxanes is not possible using polystyrene (PS) standards. It can be achieved either by using a gel permeation chromatographic method with PDMS standards or by a calculation from the Mark‐Houwink equation using experimental values of intrinsic viscosity.
Synthesis and Surface Acidity of MeAPO‐5 Molecular Sieves
Authors: Yang Sze‐Ming , Wu Shiaw‐Tzong , Lin Shiow‐Shyong
Published: June 2015

Metal substituted aluminum phosphate molecular sieves, MeAPO‐5 (Me = Co, Mn, Fe(II), Fe(III), and Mg) were synthesized and characterized with X‐ray diffraction and scanning electron microscopy. The acidity was determined by temperature programmed desorption of ammonia, Desorption peaks at around 200°C were observed for all the MeAPO samples studied. Additional desorption peaks at around 300°C were found in MnAPO‐5, CoAPO‐5, and MAPO‐5. MnAPO‐5, CoAPO‐5, and MAPO‐5 also show good activities toward the cracking reaction of cumene at 350°C, while Fe(II)APO‐5 and Fe(III)APO‐5 show some activity at 500°C. The order of the cracking activity correlates with the presence of strong acidic sites in MnAPO‐5, CoAPO‐5, and MAPO‐5 as indicated by the TPD of ammonia.
Synthesis of Furanoid Natural Products
Authors: Liu Wan‐Hwa , Wu Hsien‐Jen
Published: June 2015

Furanoid natural products, 1‐ipomeanol(17), 4‐ipomeanol(7), 1,4‐ipomeadiol(10) and ipomeanin (9) were synthesized from the intermediate compound (5) which was obtained by the photoaddition of furan with cyclopentanone followed by isomerization of the photoadduct(3).
The Alkaloid of Cananga Odorata (I), Isolation of A New Base, Ushinsunine N‐Oxide
Authors: Yang Tsang‐Hsiung , Huang Wen‐Yen
Published: June 2015

A new aporphine alkaloid was isolated from the stem bark of Cananga odorata Hook. f. et Thomson (Annonaceae). The structure of this alkaloid has been established as ushinsunine N‐oxide (6aS, 7R) (1) on the basis of spectroscopic evidences and by chemical transformation.
Preliminary Results on the Crystal and Molecular Structure of Native and Mutant Aspartate Carbamoyltransferase at Neutral pH
Authors: Lu Tian‐Huey , Young Ti‐Sheng , Schachman Howard , Kim Sung‐Hou
Published: June 2015

The cell dimensions are a=b=131.2, c=198.5 Å, and α= β =90°, γ = 120° for both the wild and the mutant types of aspartate transcarbamoylase (ATCase) crystallized at pH=7.0. The space group is R32. Although the mutant and wild forms of ATCase show large differences in enzyme activity and chemical reactivity, yet they are isomorphous in structure.

One asymmetric unit of ATCase contains a catalytic subunit, molecular weight 34,000 daltons, and a regulatory subunit, molecular weight 17,000. There are 310 amino acids in the catalytic subunit and 162 amino acids plus zinc in the regulatory subunit. The whole ATCase is a hexamer and consists of six molecules of catalytic and regulatory subunits. The primary structure study of this enzyme shows that the mutant form has a single substitution of aspartic acid in place of glycine at position 128 in the amino acid sequence of the catalytic chains. In most part of the sequence, the regulatory and catalytic chains of mutant and wild forms of ATCase are in similar conformations.

(2Fo‐Fc) syntheses displayed with computer graphics using the FRODO program, were applied to the reflection data from both mutant and wild types. A stereoview of certain regions displayed on PS300 graphics shows significant differences between the wild and mutant types of ATCase.
Thermodynamics of Ion‐Association of NaClO4 in Aqueous‐Methanol and Aqueous‐Glycerol Using Conductance Measurements
Authors: Emara Mostafa M. , Shehata Hassan A. , El Nkhaily Sayed H.
Published: June 2015

The conductance of NaClO4 at (25–45)°C in methanol‐H2O, and glycerol‐H2O mixtures in a concentration range up to 10−2 M has been measured. The association constant, KA, values have been determined, where the conductometric data were analysed by a M S X computer using the Fuoss‐Aprano method. The KA values for NaClO4 in methanol‐H2O are higher than in glycerel‐H2O mixtures, Also KA values increase as the proportional of methanol or glycerol increases in mixture. The thermodynamic parameters ΔH°, ΔG°, and ΔS° were also calculated. It is obvious that the entire process of the ionic association in those systems are endothermic ones. The Walden products, Λoη were calculated for all systems investigated.
Cyclic Voltammetric and Morphological Studies of Polyaniline
Authors: Yang Sze‐Ming , Lin Tsair‐Sheng
Published: June 2015

Cyclic voltammograms and morphology of polyaniline were studied under various synthetic conditions and in various protonic acid media. The effect of protonic acid is not remarkable. The cyclic voltammogram and morphology depend on the synthetic conditions. The anodic peak potential at 0.14 V versus SCE in the cyclic voltammogram is pH independent. The anodic peak potential at 0.7 V versus SCE (pH=1) is pH dependent. By comparing the range of pH and oxidation potential of the conductive form, we propose that the conductive species which exists in the potential range between the first and the second peak in cyclic voltammogram is the radical cation.
The Diels‐Alder Reaction of Dienes Derived from Substituted 3‐(Phenyl‐Thio)‐3‐Sulfolenes
Authors: Chou Shang‐Shing P. , Liou Shy‐Yeon , Tsai Chung‐Ying
Published: June 2015

Substituted 3‐(phenylthio)‐3‐sulfolenes (3) and (4) are good precursors for 2‐(phenylthio)‐1,3‐butadienes (5) and (6). The Diels‐Alder reaction of the dienes derived from (3) and (4) with various dienophiles was studied. It was found that heating of sulfolenes (3) with methyl propiolate and N‐phenylmaleimide afforded the Diels‐Alder adducts of (5) directly and with complete regio‐ and stereospecificity. The same reaction with methyl vinyl ketone gave a mixture of endo and exo addition products. If sulfolenes (3) were first converted to the dienes (5) using lithium aluminum hydride and then reacted with methyl vinyl ketone in the presence of anhydrous zinc chloride, the stereoselectivity could be improved. Sulfolenes (4) also underwent cycloreversion/cycloaddition with methyl acrylate, methyl vinyl ketone, and N‐phenylmaleimide, but gave mostly the double bond‐isomerized cycloaddition products. The regiochemistry of cycloaddition was delicately dependent on the dienophiles used.
Synthesis of Certain S‐Triazole and s‐Triazolo[3,4‐B] 1,3,4‐Thiadiazole Derivatives of Expected Pharmacological Activity
Authors: Eisa H. M. , El‐Emam A. A. , Moustafa M. A. , El‐Kerdawy M. M.
Published: June 2015

Reaction of the newly prepared 3‐(2‐thienyl)‐4‐amino‐s‐triazole‐5‐thione (I) with different alkyl kalides and aromatic aldehydes afforded the corresponding thioethers and arylidene derivatives (II and III), respectively. Attempt ring closure of (I) with acetic anhydride produced the unexpected triacetyl derivative (IV). The synthesis of certain 3‐(2‐thienyl)‐6‐substituted‐s‐triazolo[3,4‐b] 1,3,4‐thiadiazoles (V and VII) was described. IR, NMR and mass spectral analyses of the prepared compounds were discussed.
Preparation and Characterization of High‐Tc YBa2Cu3O7‐X Superconductors by Means of Gelation of Metal Dicarboxylate Complexes
Authors: Liu Ru‐Sie , Chang Chau‐Ting , Wu Pin‐Tien
Published: June 2015

The superconductors YBa2Cu3C7‐x have been prepared via gelation of metal dicarboxylate complexes. Physical measurements such as XRD, Tc, and Xac on these ceramics indicate consistently that a better superconducting behaviors were found than that obtained from previously reported oxalate process.
Preparation of Poly(p‐Phenylene), Poly(m‐Phenylene), and Poly(2,5‐Thienylene) Via Electron Transfer from Aryl Grignard Reagents to 2,3‐Dichloropropene
Authors: Luo Fen‐Tair
Published: June 2015

Three polymers including poly(p‐phenylene), poly(m‐phenylene), and poly(2,5‐thienylene) were synthesized in good yields from the corresponding aryldimagnesium bromide with two equiv of 2,3‐dichloropropene. The polymerization process involving electron transfer from the Grignard reagent to 2,3‐dichloropropene is proposed.
The Diels‐Alder Reaction of 2,3‐Disulfur‐Substituted 1,3‐Butadienes
Authors: Chou Shang‐Shing P. , Sun Der‐Jen
Published: June 2015

The 2,3‐disulfur‐substituted 1,3‐dienes (1) can be readily prepared from their stable 3‐sulfolene precursors (2) by thermal extrusion of SO2. The Diels‐Alder reaction of diene (1) with several dienophiles has been studied. The substituent effect on the reactivity and regioselectivity follows the order of PhS >PhSO >PhSO2. Lewis acid can greatly increase the regioselectivity of this reaction. The diene (1c), bearing a strong electron‐withdrawing sulfonyl group, also reacted as a dienophile.
The 1,3‐Dipolar Cycloadditions of 3‐Arylsydnone‐4‐Carbonitrile Oxides with Nitriles
Authors: Yeh Mou‐Yung , Pan I‐Horng , Chuang Che‐Ping , Tien Hsien‐Ju
Published: June 2015

3‐Arylsydnone‐4‐carbonitrile oxides (2), which are generated in situ by thermal dehydrochlorination of the corresponding hydroximic acid chlorides (1), undergo 1,3‐dipolar cycloadditions with sydnone‐4‐carbonitriles (6) to give 3‐aryl‐4‐[5‐(3‐arylsydnonyl)‐1,2, 4‐oxadiazol‐3‐yl] sydnones (9). These nitrile oxides (2) also react with alkyl‐ and arylnitriles to give 1,3‐dipolar cycloaddition products.
A Convenient Method for the Preparation of Nitriles from Aldehydes and Aldoximes
Authors: Yeh Mou‐Yung , Tien Hsien‐Ju , Tung Ching‐Hsuan , Hwang Chi‐Ching , Wu Tian‐Shung
Published: June 2015

Nitriles were prepared from their corresponding aldehydes or aldoximes with the Vilsmeier reagent in a one‐pot reaction or without another solvent at room temperature in 74‐98% yields.
Encapsulation and Prolonged Release Behaviour of W/O/W Type Multiple Emulsions
Authors: Lin Tsui‐Hua , Lin Shan‐Yang
Published: June 2015

W/O/W type multiple emulsions were prepared by two step emulsification procedures using an oily lymphographic agent, lipiodol, as an inner oil phase and Pluronic F‐68 as a hydrophilic emulsifier contained in the outer aqueous phase. Span 80, Pluronic L‐64 and HCO‐60 were used as emulsifiers incorporating them into the inner oil phase. The phase volume of the inner and outer aqueous phases and the yield of the w/o/w type multiple emulsions were studied. The dissolution behaviour of the w/o/w type multiple emulsions were determined by a dialysis method employing cellulose tubing. The effect of emulsifier type and the amount of HCO‐60 on the stability and prolonged release behavior of the w/o/w type multiple emulsions with or without lecithin, was also examined. The results indicate the HCO‐60 is a better emulsifier than Span 80 or Pluronic L‐64. Its use improves the stability and the prolonged release behavior of w/o/w type multiple emulsions.
Spectrophotometric Determination of Iron and Cobalt in Super Alloys
Authors: Tsai Suh‐Jen J. , Jong Yih‐Ling
Published: June 2015

The quantitative analysis of iron and cobalt in super alloys has been studied. 1,‐10‐Phenanthroline and nitroso‐R salt provide the chromophores for iron(II) and cobalt(II), respectively. The possibility of applying these photometric methods to a relatively complex substance, such as a super alloy, has been evaluated on the bases of precision and accuracy. The absorbance characteristics of metal complexes and the possible interference from foreign ions have also been carefully investigated. The presence of a high concentration of Ni results in a reducation of the amount of 1,10‐phenanthroline available for the formation of ferroin complexes while Mo does not have this effect. The analytical methods have been applied to the super alloys, Inconel 718, Hastelloy X, and Inconel X‐750. The modified 1,10‐phenanthroline photometric method and the standard nitroso‐R salt photometric method give high accuracy and good precision. This illustrates the analytical applicability of these reagents to super alloys.
Voltammetric Study of Ferrocene/Ferricinium Ion Redox Reactions in Acetonitrile
Authors: Fann Yang‐Cheng , Hao Hsieh‐Sui , Kapoor R.C.
Published: June 2015

Cyclic voltammetric and differential pulse voltammetric characteristics of the oxidation reaction of ferrocene in acetonitrile solvent have been evaluated using a glassy carbon indicator electrode. The redox couple ferrocene/ferricinium ion approaches thermodynamic reversibility in acetonitrile medium in only a low concentration range.
Organotransition‐Metal Complexes of Multidentate Ligands 6. Electronic and Steric Influences on the Formation of η2‐Acyl Complexes
Authors: Shiu Kom‐Bei , Lee Li‐Yun
Published: June 2015

Three new η2‐acyl complexes, TMo(CO)2(η2‐COR) (T = Tp', Tp'; R= Me, Bun; Tp' = hydridotris(3,5‐dimethyl‐pyrazol‐1‐yl)borate; Tp' = hydridotris(3,4,5‐trimethylpyrazol‐l‐yl)borate) prepared from the corresponding alkyl iodides, RI, and the anions, TMo(CO)−3. The preparation of Et4N+Tp Mo(CO)3− is also described. Using solution IR spectra to monitor the reactions between RI and TMo(CO)3−, it was found that Tp'Mo(CO)2(η2‐COMe) was formed more readily than Tp'Mo(CO)2(η2‐COMe) which was obtained more easily than Tp'Mo(CO)2(η2‐COBun). This finding suggests that the mechanism is probably an ionic substitution rather than a radical mechanism. The different times required for the complete conversion from the anions to TMo(CO)2(η2‐COR) is rationalized in terms of the electronic and steric influences of T and RI.
Preparation and Conductivity of Benzophenone‐Iodine‐Alkali Iodide Crystals Grown from Methanol
Authors: Wang Chi‐Ming , Wang Su‐Fen , Chang Hua
Published: June 2015

Polyiodide complexes of benzophenone (B) with iodine (I) and alkali iodide (MI, M = Na, K, Rb or Cs) have been prepared from methanol for the first time. The crystals of these complexes (abbreviated BIMI) are in the shape of hexagonal prisms with golden luster sides and black cross sections. BIMI complexes exhibit semiconductive behavior from 250 to 310 K with activation energies of 0.6 to 0.8 eV. Under an applied dc field at room temperature, the longitudinal conductivity of BIMI crystals is in the order of 10−6 Scm−1 and does not decrease over a period of half an hour, indicating no ionic conductivity in these complexes. In contrast, significant ionic conductivity is observed for benzophenone complexes grown from chloroform. It is concluded that the solvent molecules play an important role in determining the electrical behavior of the resulting benzophenone complexes. The results of conductivity and resonance Raman spectroscopic studies on the entire methanol series of BIMI complexes suggest that a common conduction pathway is probably provided by the polyiodide chains in this new series of benzophenone complexes.
Angular Distribution of the Multipole and Multiphoton Photofragmentation of Molecules
Authors: Chiu Ying‐Nan
Published: June 2015

The effect of higher‐order photo‐excitation on the angular distribution of photo‐dissociated molecular fragments is studied. A general formalism is derived that will cover non‐linear as well as linear polyatomic molecules and will permit comparison of the processes of different orders. Some of the higher‐order processes, e.g., magnetic dipole and electric quadrupole, will give rise to azimuthal‐angle (Φ) besides polar‐angle (θ) dependence of the fragments. Using a molecule of D3h, Symmetry as an example, a comprehensive study is made of all possible excitations allowed by symmetry in this point group for one‐photon electric/magnetic dipole and three‐photon electric‐dipole transitions. Plane wave approximation is used for the relative motion of the random and non‐rotating molecules which dissociate instantaneously with a velocity large compared with thermal motion. These basic angular factors may be used in future extensions to rotating and vibrating molecules and to time‐delayed dissociations and to vibronically excited fragment states, etc.
Transition Metal Complexes of Azo‐8‐Hydroxyquinoline Derivatives as Antimicrobial Agents
Authors: Awad Ibrahim M.A. , Aly Aref A.M. , Abdel Hafez Aly A. , Hassan Kh. M.
Published: June 2015

Some New azo sulphonamide derivatives containing 8‐hydroxyquinoline moiety and their complexes with some transition metal ions vz. Fe+3, Co+2, Ni+2, Cu+2, and Hg+2 have been prepared and characterised. The stereochemistry as well as the type of bonding around the metal ions were determined on the basis of microanalysis, IR and UV‐VIS spectra, conductivity and magnetic moment measurements; the thermal behaviour of the complexes was also studied. The metal ions coordinate exclusively to the 8‐hydroxyquinoline moiety. The biological activity of the complexes was tested against a number of bacteria. Chelation of the metal ions to the ligands induces a remarkable increase in their antimicrobial activity.
Selective Synthesis of 1‐Alkyl‐2‐(Phenylsulfonyl)‐1,3‐Butadienes
Authors: Chou Shang‐Shing P. , Tsai Chung‐Ying , Sun Chung‐Ming
Published: June 2015

Selective synthesis of the title compounds from the corresponding sulfenyldienes is described.
Additional Constituents of Hypericum Subalatum
Authors: Chen Ming‐Tyan , Kuoh Yu‐Ping , Wang Chao‐Hsiung , Chen Chiu‐Ming , Kuoh Chang‐Sheng
Published: June 2015

The whole herb of Hypericum subalatum Hayata contains three flavonoids, caffeic acid esters, a pyranoxanthone, and three xanthines, in addition to the previously reported xanthonolignoids. Among these compounds, 2,7‐dihydroxy‐3,4‐dimethoxyxanthone has not been described in the literature before. The co‐occurrence of xanthone derivatives and flavonoids in this plant is of chemotaxonomic significance.
Analysis of Triorganotin Compounds by High‐Performance Liquid Chromatography with Reverse‐Pulse Amperometric Detection
Authors: Whang Chen‐Wen , Tsai Wen‐Li
Published: June 2015

High‐performance liquid chromatography (HPLC) coupled with the reverse‐pulse amperometric (RPA) detection method has been developed for the analysis of triorganotin compounds in aqueous solutions. The major advantage of RPA vs. conventional amperometric detection is its ‘in situ’ elimination of interference from dissolved oxygen in the chromatographic eluent; therefore, no extra chemicals or apparatus are required for oxygen removal. With a Partisil‐10 SCX column and an eluent of methanol/0.01 M sodium acetate buffer (70:30, pH 5.5), the four triorganotins, viz., trimethyl‐, triethyl‐, tripropyl‐, and tributyltin, can be totally separated. Detection by RPA was performed with a static dropping mercury electrode with an initial potential of −1.15 V and a final potential of +0.15 V. The absolute detection limit (S/N = 3) ranged from 12 ng of tributyltin (as tin) to 0.3 μg of trimethyltin (as tin). Applications of the method to the analysis of trace tributyltin in marine antifoulant leachate and sea water are described.
Preparation and Superconductivity of a Series of Bi2CaSr2‐XBaxCu2O8+δ
Authors: Wang Men‐Hour , Kao Huey‐Chuen I.
Published: June 2015

By means of the addition of Ba into the Bi‐Ca‐Sr‐Cu‐O 2122 system, a series of Bi2CaSr2‐xBaxCu2O8+δ (0 ≤ × ≤ 2) quinary metal oxides were prepared by the citrate route and by the conventional powder reaction method. The samples prepared by the former method have better properties than the latter. It was found that 5 was not equal to zero for all of them and that it increased with decreasing Tc. Two phases were indentified in the oxides containing all five metal elements. One is the Bi‐Ca‐Sr‐Cu‐O 2122 phase, the other is a new insulating phase which probably contains Bi‐Ca‐Ba‐Cu‐O with undetermined stoichiometry. Superconductivity was found in those samples for which × ≤ 1.50 with their Tc onsets between 93–78 K by resistivity measurements. Superconductivity decreased monotonically with increasing x. However, residual resistance was found in those samples for which 1.00 ≤ × ≤ 1.50, The Meissner effect appears in the samples where × ≤ 1.00 with Tc onsets between 88–80 K. For x = 1.75 and 2.00, the samples were semiconductors with resistivities of 6.66 × 102 and 6.96 × 103 Ω cm at 290 K, and activation energies of 0.109, and 0.298 eV, respectively.
Synthesis and Reactions of a Stable Precursor to Dienes Containing Both Silicon and Sulfur Substituents
Authors: Chou Shang‐Shing P. , Tsai Chung‐Ying , Sun Chung‐Ming
Published: June 2015

3‐(Phenylthio)‐4‐(trimethylsilyl)‐3‐sulfolene (2) was readily prepared by chlorosulphenylation‐dehydrochlorination of 3‐(trimethylsilyl)‐3‐sulfolene (4b). Treatment of 2 with n‐butyllithium at −105 °C followed by an alkylating agent gave only C5 alkylation products 6 demonstrating the stronger carbanion stabilizing ability of phenylthio group than that of trimethylsilyl group. 2‐(Phenylthio)‐3(trimethylsilyl)‐1,3‐butadiene (3a) was readily prepared by thermal extrusion of sulfur dioxide from 2. Selective oxidation of 3a with MCPBA gave the sulfinyl (3b) and sulfonyl (3c) derivatives. The Diels‐Alder reactions of 3a‐c were studied, and the regiocontrolling power of the substituents follows the order PhS >PhSO ∼ PhSO2 >Me3Si.
Thermodynamics of Copper(II) Complexes of Diamino Diamides in Aqueous Solution
Authors: Chao Min‐Shiun , Chung Chung‐Sun
Published: June 2015

The equilibria occurring in aqueous solutions of N,N′‐bis(β‐carbamoylethyl)ethylenediamine, N,N′‐bis(β‐carbamoylethyl)trimethylenediamine, N,N′‐bis(β‐carbamoylethyl)‐1,2‐propylenediamine, and N,N′‐bis(β‐carbamoylethyl)‐2‐hydroxytrimethylenediamine with protons and copper(II) ions as well as the deprotonation reactions of the copper (II) complexes of these four ligands have been studied by calorimetry at T=25.0°C and I=0.10 mol dm−3 (NaClO4). The enthalpy changes and the entropy changes for these reactions are reported and discussed.
Fluorescence Probe Studies of Ionic Micelles in Concentrated Salt Solutions
Authors: Chen Jin‐Ming , Su Tzu‐Min , Mou Chung Yuan
Published: June 2015

We have investigated the effect of salt concentration and temperature on the average aggregation number and micro‐polarity of the interior of micelles of sodium dodecyl sulfate (SDS). sodium tetradecyl sulfate (STDS) and lithium dodecyl sulfate (LiDS). The transient fluorescence decay of micelle‐solubilized pyrene has been measured and analyzed. An exponent weighted average aggregation number e was obtained by this technique. For SDS and STDS in NaCl solution, e increases as the temperature is lowered or salt concentration is increased e increased from ∼ 50 to ∼ 250 over [NaCl] = 0 to 0.8 M. Due to the strong counterion binding of lithium in the micellar solution, the LiDS micelle is much, smaller and does not increase appreciabily even at [LiCl] =0.8 M. From the fluorescence spectrum fine structure of pyrene and the fluorescence decay of the monomer and excimer, we can understand the local polarity and the water penetration to the interior of the micelle upon addition of salts and with changing temperature. The interior of the micelle becomes more nonpolar as the salt concentration is increased and the temperature is lowered. A complete kinetic analysis of the time–dependence of the fluorescence is given. The kinetic analysis is in agreement with the results reached by fluorescence spectral analysis.
Synthesis and Some Chemical Behaviour of Certain Substituted Thiosemicarbazides
Authors: El‐Kerdawy M. , Eisa H. , Barghash A. , Marouf A.
Published: June 2015

Three new thiosemicarbazides (1 a‐c) were prepared from N‐[4‐phenyl‐5‐(2‐thienyl)‐1,2,4‐triazol‐3‐yl]mercaptoacetohydrazide. Reaction of (1 a‐c) with the appropriate phenacyl bromide afforded thiazoline derivatives (2 a‐i) whereas their reaction with chloroacetic acid or maleic anhydride gave the corresponding thiazolidine derivatives (3 a,b) and (4 a,b). Cyclodesulfurization of (1 a‐c) with DCCD in toluene yielded 5‐substituted‐amino‐1,3,4‐oxadiazoles (5 a,b), while their dehydration with PPA gave the corresponding 5‐substituted‐amino‐1,3,4‐thiadiazoles (6 a‐c). Six representative compounds were tested for their in‐vitro antimicrobial activity against some pathogenic microorganisms, some of them were proved to be active.
A New Synthesis of α‐Myrcene
Authors: Tso Hsi‐Hwa , Chou Ta‐Shue , Lai Yu‐Ling
Published: June 2015

α‐Myrcene was synthesized from 4‐[(1‐hydroxy‐4‐methyl)‐4‐pentenyl]‐2‐sulfolene (3) by a sequence of mesylation, elimination, Michael addition, desulfurization, and thermolysis.
Mesophases I
Authors: Ogilvie J. F.
Published: June 2015

In this review of the properties and applications of mesophases, after a general description of the states of aggregation of matter, the types of liquid crystals are distinguished. The thermotropic liquid crystals are classified on the basis of their structural properties. A comparison of sets of chemically related molecules indicates how details of molecular structure (topology and conformation) affect the existence and sequence of mesophases for the lath‐like thermotropic mesogens.
Relaxations Studies of 2IZSZ Spin Order with Signal Enhancement by Coherence Transfer
Authors: Chang Wen‐Tsung , Hwang Lian‐Pin , Wang Pei‐Lejn
Published: June 2015

The pulse sequence for generating coherence transfer (or polarization transfer) is invoked to enhance the signal of heteronuclear two spin order (e.g. 2IZSZ) in a spin system with CH moiety. This allows the observation of selective conversion of Zeeman order, in a sample with natural abundant 13C nuclei, into two spin order for measuring cross‐correlation of chemical shift anisotropy and dipole‐dipole interactions. The molecular reorientational correlation time and the orientation of the C–H axis with respect to the principal axes of carboxyl CSA tensor may be determined simultaneously in the relaxation profile of two spin order.
Sequence Determination of a Tetrapeptide Using Long‐Rang Heteronuclear Shift Correlation 2D NMR Spectroscopy
Authors: Shi Fong‐Ku , Lin Ying‐Chih , Wang Kung‐Tsung
Published: June 2015

A tetrapeptide has been studied by means of NMR of 13C in natural abundance. By the combined application of various two‐dimensional 1H/1H and 13C/1H correlation techniques, the primary structure of the peptides could be unambiguously determined.
Electrophilic Reactions of Dithio‐Substituted o‐Methoxycinnamyllithium
Authors: Chen Ming‐Yi , Fang Jim‐Min
Published: June 2015

The dithio‐substituted o‐methoxycinnamyllithium 3L reacted at the α‐site with D2O and most of carbonyl compounds in extents of 70–100 %. while it reacted with halides at either the α or γ‐site, depending on the nature of respective halide.
Mesophases II
Authors: Ogilvie J. F.
Published: June 2015

In the continuation of a review of the classification, properties and applications of mesophases, the general features of thermodynamic data of thermotropic liquid–crystalline phase transitions are surveyed. The orientation of molecules in liquid–crystalline mesophases is discussed in relation to the electrical properties. Some applications of mesophases are outlined. After surveys of both the structural classes of lyotropic mesophases and the properties of plastic crystals in cubic phases, the thermodynamic, structural and other properties of all mesophases‐are summarily considered in relation to the present state of the knowledge in this field.
Adsorption/Thermal Desorption with Tenax‐GC for the Collection and Analysis of Polycyclic Aromatic Hydrocarbons and Chlorinated Compounds
Authors: Sye Wen‐Fa , Chang Chin‐Liang
Published: June 2015

A system for the determination of polycyclic aromatic hydrocarbons(PAHs) and chlorinated compounds in air by means of adsorption/thermal desorption(ATD) with small bed volume (0.1 g) Tenax cartridges, followed by cryogenic trap in a U‐shaped stainless steel tube with liquid nitrogen as an appropriate concentration method prior to capillary gas chromatography is described. Recoveries were determined for the complete ATD method. Desorption recoveries near 100% were found for a variety of chlorinated compounds and polycyclic aromatic hydrocarbons.
Analysis of Seven Herbicides by Gas‐Liquid Chromatography
Authors: Wang Wan‐Kung , Huang Shang‐Da
Published: June 2015

Simutaneous analysis of seven commonly used herbicides, 2,4‐D methyl ester, 2,4‐D methyl ester, 2,4,5‐T methyl ester, silvex methyl ester, ramrod, CIPC and DEF, by gas‐liquid chromatography with an electron capture detector was attempted. Two packed columns (which are generally used for the analysis of chlorinated pesticides) and two chemically bonded fused silica capillary columns were used for the analysis. When the packed columns were used, ramrod always interfered with the analysis of 2,4‐D methyl ester and/or silvex methyl ester. Complete separation with reasonable analysis time can be achieved using one of the chemically bonded fused silica capillary columns.
The Photochemistry of Ch3I in Various Matrices at Low Temperature
Authors: Yeh Syun‐Ru , Chang Hua
Published: June 2015

The photodissociation of methyl iodide in various matrices at low temperature was studied. The observed Raman spectra excited by 514.5 nm laser radiation showed that there were two different photolytically produced iodine species isolated in the matrices after illumination by a medium pressure mercury lamp. One species which was dominant at lower iodine concentrations and exhibited a progression with an ωe of 201 cm−1, belonged to the matrix isolated iodine monomer (I2). The other species, which was dominant at higher iodine concentrations with an ωe of approximately 180 cm−1, belonged to the iodine aggregate ((I2)n). Five progressions of resonance Raman or resonance fluorescence of these two species were also observed in the other matrices. The iodine aggregate in the methyl iodide matrix at 77 K was formed in a crystalline structure, while the photolytically generated iodine aggregate from CH3I/Ar (2/3) matrix at 10 K, after illumination with a mercury lamp, was in amorphous form. The rearrangement of photolytically produced iodine aggregate in methyl iodide matrix was observed as a function of the duration of illumination. Local heating effects of the laser radiation might induce the iodine monomer to aggregate in matrices. The photodissociation mechanism of methyl iodide in matrices is also proposed.
Current Developments in Optical Emission Spectrometry with High‐Frequency and Microwave Induced Plasmas
Authors: Broekaert J.A.C.
Published: June 2015

The state‐of‐the‐art and trends of development with the inductively coupled plasma (ICP) and microwave induced plasmas (MIP) as radiation sources for optical emission spectrometry arc presented. Especially techniques for sample introduction are discussed. Here special reference is given to the use of spark ablation as well as 10 direct sample insertion and slurry atomization for the direct analysis of powder samples. The development in MIP optical emission Spectrometry is shown to center on the improvement of the plasma sources, their characterization and their tailoring to various sampling techniques. Results of the use of pneumatic nebulization of liquids and electrothermal evaporation of dry solution residues will be presented.
Standard Chemical Thermodynamic Properties of Perfluoro N‐Alkanes
Authors: Wen Chung‐Ming
Published: June 2015

The chemical thermodynamic properties Cp°, ΔHf° S°, ΔGr° and Kp of gaseous perfluoro n‐alkanes, P(CF2)n F(2≤n≤10), have been calculated from 298.15 to 1000 K using the Benson method with Cp° = a″;b/T + c/T2, Cp°=a+bT+c+/T2 and Cp°=a″ + bT +cT2. Better results are obtained for Cp°=a+b/T+c/T2. The calculated chemical thermodynamic properties of C2 F6 (g) are in excellent agreement with the literature data of Stull, Westrum, and Sinke under IBM/PC microcomputer with STEP data base management system.
Axial and Equatorial Dimethylamine Substitution on Phosphorus in the 1,3,2‐Oxazaphosphorinane Ring System: Structures of 2‐Dimethylamino‐4‐Phenyl‐2H‐1,3,2‐Oxazaphosphorinane‐2‐Oxides
Authors: Liu Ling‐Kang , Shih Yun‐Er , Li Yann‐Shiang
Published: June 2015

Single crystal x‐ray structures of the diastereomeric 2‐dimethylamino‐4‐phenyl‐2H‐1,3,2‐oxazaphosphorinane‐2‐oxides, 5c and 6c, have been determined. The pair has been prepared in a straightforward manner by reaction of 3‐amino‐3‐phenylpropanol with Mo2P(O)Cl2, and separated into pure forms by column chromatography. Crystal data of 5c: space group P21/n, a = 11.087(3), b = 6.087(6), c = 18.465(6)Å, β = 98.40(3)°, R = 0.035 for 1845 reflections. Crystal data of 6c: space group P21/n, a = 11.176(2), b = 6.893(2), c = 16.673(3)Å, β = 95.29(1)°, R = 0.037 for 1253 reflections. The fast‐migrating 5c is cis (Ph and P = O group cis) with the configuration of 2RS, 4SR. The slow migrating 6c is trans with the configuration of 2RS, 4RS. In both structures the 1,3,2‐oxazaphosphorinane rings are chair like with the P‐end essentially flattened, The skeleton made up with 4‐phenyl‐1,3,2‐oxazaphosphorinane is essentially the same. With a conformationally demanding 4‐phenyl substituent, 5c has an axial Mc2N whereas 6c has an equatorial Me2N. For 6c, the exocyclic P‐N bond has a partial double bond character the geometry about exocyclic N is planar. On the other hand, for 5c, the geometry about exocyclic N deviates considerably from planarity, the sum of the angles around N being 348.1°. In the crystalline state, the screw‐related 5c molecules are hydrogen bonded whereas in the crystalline state, the centro‐symmetrically related 6c molecules are paired‐up by hydrogen bonds, both through the N‐H and P = O system.
New Developments in Activation Analysis for Material and Environmental Sciences
Authors: Alfassi Zeev B.
Published: June 2015

Activation analysis in general and mainly reactor neutron activation analysis (NAA) has been used extensively for measuring trace elements in high purity materials, particularly semiconductor materials. The advantages of NAA in determination of trace elements differ from one semiconductor material to another. For all of them the inherent properties of activation analysis especially those of non contamination with the reagents, low blanks and high sensitivity are the reasons for the choice of NAA as the main analytical procedure. These inherent properties are essential for analysis of high‐purity materials where concentrations of ppb's and sub ppb's have to be measured.

NAA is specially suitable for the determination of trace elements in silicon due to the very short lived very low activity induced by neutron reaction in silicon. This enables easy instrumental (i.e. without chemical separations) determination of trace elements in silicon. In the HFR reactor at Peten, Netherlands, a special facility was constructed for irradiation of silicon samples of Philips, in which silicon wafers of up to 15 cm diameter can be irradiated with 4 × 1013n. cm−2. sec−1 and the irradiation is done for 72–96 hours. using large Ge(Li) detectors (100 to 150cc) and long counting time (8–16 hours) they measured 22 elements in concentrations below ppb and 10 others between ppb and 300 ppm. Trace elements in germanium have been determined both instrumentally after very long decay time (100 days) or after short decay time removing the activities from the matrix by chemical separation. Trace elements in GaAs are determined only after chemical separtion. Several other semiconductor material such as Sc, Te, GaP and CuInS2 were also determined by NAA.

Some trace elements cannot be determined by neutron activation. Carbon, nitrogen and oxygen are determined by activation with protons, alphas or 3He particles. Boron and hydrogen are determined by prompt emission induced by charged particle activation, which gives not only the total concentration but also the depth profile. Carbon, nitrogen, oxygen and phosphorus were also determined by prompt proton activation analysis.

The environmental samples studied by activation analysis can be divided into three categories: atmospheric aerosols, water samples and solid wastes. NAA of atmospheric aerosols have been used for their posible toxicological hazards, their source identification and for studies of atmospheric transport processes.
NMR and Molecular Genetics as Tools for Investigating Protein Interactions in Membrane Systems
Authors: Pratt E. A. , Ho Chien
Published: June 2015

In our laboratory, we have applied the tools of nuclear magnetic resonance (NMR) spectroscopy and molecular genetics to investigate the structural and dynamic properties of membrane‐associated proteins and their interactions with membrane components. There are two general classes of membrane proteins, i.e., intrinsic and peripheral ones. For the intrinsic membrane proteins, we have chosen the membranebound D‐lactate dehydrogenase (D‐LDH) of Escherichia coli as a model to study protein‐lipid interactions in membranes. D‐LDH is a respiratory enzyme of molecularweight 65, 000 containing flavin adenine dinucleotide (FAD) as a cofactor. The activity of purified D‐LDH is enhanced up to 100‐fold by lipids and detergents. The gene for D‐LDH has been sequenced, and production of the enzyme amplified up to 300‐times normal levels. We have biosynthetically incorporated 5‐fluorotryptophan (5F‐Trp) into D‐LDH and studied the five Trp residues by 19F‐NMR spectroscopy. In order to gain additional information using 19F‐NMR, site‐specific, oligonucleotide‐directed mutagenesis has been used to insert a sixth Trp into D‐LDH at various positions throughout the 571‐amino acid chain. These mutant D‐LDHs are being characterized biochemically and through NMR. For peripheral membrane proteins, we have chosen two periplasmic binding proteins, histidine‐binding protein J (J protein) of Salmonella Typhimurium and glutamine‐binding protein (GlnBP) of E. coli as models to investigate the structure‐function relationship in periplasmic binding protein‐mediated active transport systems. These two proteins both have molecular weights of approximately 25, 000. By using mutant J proteins and GlnBPs and site‐specific, oligonucleotide‐directed mutagenesis techniques, we have assigned several resonances to specific amino acid residues. We are investigating the relationship between ligand‐induced conformational changes in these two proteins and their roles in the active transport of ligand across the cell membrane. We have found that a combination of isotopic labeling, biochemistry, molecular biology, and NMR is a very useful approach to investigate various interactions of membrane‐associated protein systems.
Cathodic Action of Uranyl‐5‐Sulfosalicylate Complexes at Dropping Mercury Electrode
Authors: Chen Shou‐Nen , Gi Hung‐Jang , Li Ding‐Tzay
Published: June 2015

The uranyl ion in 5‐sulfosalicylic acid (5‐SSA) solution has been investigated by polarography. The constitution of the chelate species was confirmed by conductometric titration, under the experimental conditions: temperature 25±0.1C. pH = 2.0‐9.0. ligand concentration 10‐200 mM. At pH < 4.8, the chelate species, UO2(HA)22−, is predominant. At pH 6.0. the complex species. UO2(A)24 mainly exists. The chelate species. UO2(HA)22−, and UO2(A)24, co‐exist between pH 4.8‐6.0. The diffusion coefficients and stability constants have been determined by equations derived from Ilkovic equation.
Studies of Photon Correlation Spectroscopy of the Microemulsion of H2O/Tween 80/Benzene Derivative
Authors: Hwang Jeng Shung , Gi Hung Jang , Wu Pailin , Chen Shou Nan
Published: June 2015

The microemulsion of the H2O/Tween 80/benzene derivative (C6H6, CH3C6H5, NO2C6H5 and NH2C6H5) was investigated by the technique of Photon correlation spectroscopy. Autocorrelation data were measured at 90 scattering angle and were analyzed by using a quadratic fit and linear fit. The quadratic fit was found to describe all Properties better than the linear fit, and thus the linear fit was limited to the region of very short sampling time. When the amount of benzene derivative added to the sample solution was lower than Vmax, the Z‐average mean radius, z, and the polydispersit Y, μ2/Γ2, increased as the amount of benzene derivative was increased. When the amount of benzene derivative was larger than Vmax, the aqueous and organic phases separated and the  z, and μ2/Γ2 of all phases remained constant. Emulsification did not occur in the organic phase of the H2O/Tween 80/aniline system. When we adjusted the Tween 80 concentration, it was found that z and μ2/Γ2 decreased as the Tween 80 concentration increased.
Conducting Polymer–Synthesis and Properties of an Unsymmetrical Disubstituted Polyacetylene–Polyiodocyanoacetylene
Authors: Hsieh Bor‐Tsung , Jiang George Jang‐Jyi
Published: June 2015

The unsymmetrical disubstituted acetylene, iodocyanoacetylene (ICA), can be polymerized at 140°C in the solid state in high yield. The resulting polymer, polyiodocyanoacetylene (PICA), is a black lustrous stripe having the structure of . If the polymerization temperature is raised above 160°C, part of the iodine will split off from the polymer. However, at higher temperatures, the cyclization reaction occurs and the ladder polymer is formed. The conductivities of the pristine‐PICA and its ladder polymers are all in the semiconductor region.
Speciation, Catalysis and Transmetallation of Manganese Tetrakls(N‐Methyl‐4‐Pyridyl)Porphlne in Aqueous Media
Authors: Lin Ching‐Yao , Lin Zui‐Feng , Hseu Tong‐Ming , Oliver Su Y.
Published: June 2015

The electrochemistry and spectroelectrochemistry of manganese tetrakis(N‐methyl‐4‐pyridyl)porphine (Mn‐TMPyP) in aqueous media have been studied. For MnIIITMPyP two water molecules ligate to the metal center and the formation constant(β2) is 0.11 in acetonitrile solution. The pKa1 and pKa2 for MnIIIIMPyP(H20)2 are 10.9 and 12.3, respectively in aqueous media. There is only one pKa at 11.7 for MnIIIMPyP(H2O)2. The pKa of the oxo‐manganese(IV) porphyrin, O = MnIVTMPyP(H2O), is 11.3. MnIITMPyP demetallates rapidly to free base in acidic aqueous solution. MnIITMPyP also undergoes electrocatalysis for oxygen reduction. In acidic conditions, demetallation and catalysis rates are competitive. The transmetallation of MnTMPyP by Zn2+ can be achieved in the presence of thiols. The UV‐Visible spectra in the reaction process suggest that the formation of some reactive intermediate is essential for the transmetallation.
Mixed Ligand Complexes of Ni(II) with Arylidene‐ Anthranilic Acids and Some Lewis Bases
Authors: Ibrahim S.A. , El‐Gyar S.A. , El‐Gahami M.A. , Hammam A.M.
Published: June 2015

Some binary and ternary complexes of Ni(II) with arylideneanthranilic acids and Lewis bases have been prepared and characterized by elemental analyses, IR spectra and X‐ray powder diffraction. On the basis of the IR spectra it was found that the Schiff bases used act as monobasic bidentate ligands except for the ortho‐hydroxy derivative which acts as a dibasic tridentate ligand. From X‐ray analysis it is concluded that the binary Ni(II) chelates are isostructural, and the ternary Ni(II) complexes are also isostructural.
Spectral Properties of Bifunctional Schiff Bases, [Bis (X‐Phenyl)‐Ethane Diimine]
Authors: Mahmoud M.R. , El‐Nady A.M. , Abu El‐Wafa M. , Rabi U.M.
Published: June 2015

Electronic spectra of five (Bis(X‐phenyl)‐Ethane diimine] compounds I‐V, have been investigated in various organic solvents and aqueous buffer solutions of varying pH's. The observed visible band is assigned to intramolecular CT transition. Furthermore, it is deduced that structure of the o‐hydroxy derivative is not entirely planar. The acid dissociation constant values of the hydroxy derivatives have been determined and are discussed.
Separation of Uranium Mixing with its Decayed Nuclides and its Activated Nuclides
Authors: Wu Kuen‐Li , Lo Jem‐Mau
Published: June 2015

Extractions of uranium from the acidic media, HCl and MNO3 at different concentrations, by the tertiary amines, trilaurylamine, triisooctyllamine and trioctylamine were systematically investigated. In experiments, 232U was used as the tracer and aliquots of both phases after extractions were taken, ashed at 500°C, placed onto stainless steel planchets, and measured by a surface‐barrier Si(Li) detector connected to an alpha spectrometer. One unique condition found useful for complete separation of uranium was that of the radioactive uranium present in 8 M HCl being extracted with 10% trilaurylamine in xylene. In that case, greater than 95% of the uranium could be extracted into the organic solution, whereas all of the radionuclides of a series of its decayed products, 228h, 224Ra, 220Rn, 216Po and 212Bi remained completely in the aqueous solution. The same procedure could also be used for the separation of uranium from a mixture with its activated nuclides. Plutonium‐239 and Am were used as the tracers representing the activated nuclides of uranium. It was found that 241Am was absolutely not extracted, but that 239Pu could be extracted with ≥95% efficiency from the medium of 8 M HCl into 10% trilaurylamine in xylene. However, 239Pu could be easily stripped using the solution mixture of 8 M HCl and 0.05 M NH4I and excluded from the organic solution.
Proton NMR Studies of the Electronic Effect of Substituents at the Azomethine Carbon of N,N′‐Bisethylene (Salicylideniminato) Cobalt (II) Complex
Authors: Cheng Cheu‐Pyeng , Hwang Yaw‐Shing , Hwang Ruey‐Shyan
Published: June 2015

The proton paramagnetic shifts of low spin N,N′‐ethylenebis(salicylideniminato)cobalt(II) and its derivatives were studied to understand the effect of substituents at the azomethine carbon on the electronic structure of the Schiff‐base cobalt complexes. Analysis of the 1H paramagnetic shifts of H and CH3 bonded to the azomethine carbon reveals that spin delocalization through a interaction is responsible for the contact contribution to the paramagnetic shift. When the phenyl group is bonded to the azomethine carbon, the plane of the phenyl group is perpendicular to the plane of the complex and the phenyl group makes a negligible contact contribution to the paramagnetic shift.
The Chemisorptive Properties of Nickel Borides
Authors: Chen Yin‐Zu , Wu Jong‐Shiun
Published: June 2015

The chemisorptive properties of the nickel borides have been studied with temperature programmed desorption of H2and CO. The TPD chromatograms of H2show two major peaks at 150°C and 300°C for the P‐1 and P‐2W nickel borides and a major peak at 150°C for the DBNi and CrP‐1 nickel borides. Not all hydrogen molecules are dissociatively adsorbed on surface nickel, some hydrogens diffuse and are absorbed into the matrix of the nickel borides. Except the Cr‐promoted P‐1(P‐2W), the nickel borides do not exhibit the obvious chemisorptive capacity for CO. The Cr‐promoted nickel borides, on the other hand, not only have the obvious uptake capacity for CO but also have the good activity for CO dissociation.