bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetics of Photosensitized Polymerization of Methyl Methacrylate with Benzoin
Authors: Chen Chih‐Tsung , Huang Wu‐Der 
Published: June 2015

AbstractThe kinetics of photosensitized polymerization of methyl methacrylate with benzoin was investigated. The rate of polymerization was proportional to the square root of the concentration of benzoin and the first power of the monomer. The equation Rp=K1 ([M]‐α1) ([B]0.5+α2) was proposed, and K1 α1 and α2 were evaluated as 0.999×10−4, 0.181 and 1.11×10−2, respectively. The rate of polymerization was also proportional to the square root of light intensity in accordance with the equation Rp=5.65×10−12 I0.5. Carbon tetrachloride and chloroform markedly decreased the average degree of polymerization. The chain transfer coefficients were evaluated as 2.44 × 10−3 and 1.90 × 10−3 for carbon tetrachloride and chloroform respectively.
Hydrogen Bonding Studies in Benzoic Acid by Nuclear Magnetic Resonance Spectroscopy
Authors: Moxon K. B. , Still R. H. , Swinbourne F. J. 
Published: June 2015

AbstractThe chemical shift of the carboxyl proton in benzoic acid has been measured in a variety of aromatic solvents. The results obtained have been compared with previous data reported in this field, and discussed in this context in terms of the possible variables affecting the chemical shift.
Prelminary Reports on Structural Study via Mercury‐Sensitized Photolysis and Gas Chromatography
Authors: Tsao June C. Y. 
Published: June 2015

AbstractThe combination of photolysis and gas‐liquid chromatography results in “fingerprints” which are much superior to the pyrolysis gas chromatography method for the identification of organic compounds.With this photolysis‐GIC method, a number of methyl ethers, benzyl ethers, isopropyl ethers and tert‐butyl ethers were chromato‐graphically purified and photolytically decomposed by way of mercury sensitization.The photolytic degration products were temperature programmed in a sensitive gas‐liquid chromatograph.The “fingerprint” product peaks were calculated into retention indices, Δ I‐values and I‐values, and grouped into homologous peaks, common peaks and distinctive peaks.Identification of parent structures is obtained by the correlation of retention indices in the above three groups of peaks.
Stability of Aflatoxin B1 in Aqueous Solutions
Authors: Wei Ru‐Dong , Lee Shiuh‐Sheng 
Published: June 2015

AbstractStability of aflatoxin B1 in aqueous solutions at different temperatures and pH values was studied by thin‐layer chromatography and fluorodensitometric measurements. The rate of deterioration was found to be increased with increasing temperature and also by changing pH from neutral to alkaline or acid. In acidic buffers the aflatoxin was converted to a new fluorescent product which has much lower Rf value than aflatoxin B1 itself when chromatographed on silica gel thin‐layer plates developed with chloroform‐methanol(99:l, v/v). The UV absorption spectrum of this decomposition product has been determined.
On the Alkaloids of Nelumbo Nucifera Gaertn. Studies on the Alkaloids of Loti Embryo
Authors: Yang Tsang‐Hsiung , Chen Chi‐Ming 
Published: June 2015

AbstractA new tertiary tetrahydroisoquinoline alkaloid, methylcorypalline (V) and biscoclaurine base, neferine (II) were isolated from a Formosan lotus embryo (embryo of the seed of Nelumbo nucifera Gaertn.) (Nymphaeaceae), besides the earlier reported isoliensinine (I) and lotusine (IV).Characterization of this new base, methylcorypalline (I), mp. 58–59° (n‐hexane), , by spectral data and direct comparison with synthetic sample prepared from vanillin have proved to be 6,7‐dimethoxy‐2‐methyl‐1,2,3,4‐tetrahydroisoquinoline (V).Methylcorypalline (V) is the first instance occurring in nature having coronary dilator action.
Preparation of Iodine‐131 Labeled Hippuran by Exchange Method
Authors: Chen Ching‐Tan 
Published: June 2015

AbstractI131−labeled Hippuran was prepared by isotopic exchange reaction between ortho‐iodohippuric acid and I131‐iodide. Special emphasis was placed on the separation of I131−labeled Hippuran and its analysis with respect to the radiochemical purity. It was found that the prepared I131‐labeled Hippuran meets the requirement as the radiopharmaceutical to be used for medical purpose.
Assessment of a Radiochemical Method Using 14C‐Labeled N‐Ethylmaleimide as a Reagent for Sulfhydryl Determination with Assays on β‐Lactoglobulin and Insulin
Authors: Lai Tzen‐Son 
Published: June 2015

AbstractA radiochemical method using 14C‐labeled N‐ethylmaleimide (NEM‐14C) as a reagent for sulfhydryl determination is reassessed and described in detail. The method is based on the activity of 14C‐labeled S‐succinyl‐L‐cysteine (III‐14C) recovered from the controlled hydrolysis of the NEM‐14C treated sulfhydryl‐containing peptide and the correlation between III‐14C and SH content established with glutathione. It is simple, accurate and highly sensitive and is not affected by disulfide group as indicated by experiments with insulin. Good result is obtained from tests with β‐lactoglobulin. It gives a value of 1.94 mole SH per mole protein, which is close to that generally accepted.
Spectrophotometric Studies on Imidazole Adducts of Cupper(II) Beta‐Diketone Chelates
Authors: Chen Jung‐Tso , Wang Sunc‐Mao 
Published: June 2015

AbstractSpectrophotometric studies in the visible region have been made on chloroform solutions of CuL; [L: anions of hexafluoroacetylacetone (HFA), thenoyltrifluoroacetone (TTA), trifluoroacetylacetone (TFA) and acetylacetone (AA)J with imidazole. The acidity of CuL2 increases in the order: Cu(TFA)2 < Cu(TTA)2<Cu(HFA)2. Isolation of the adducts and the nature of the spectra is strong evidence for the formation of both 1:1 and 1:2 adducts in the chloroform solution. For Cu(AA)2‐Im, neither such a spectral evidence was observed, nor the 1:1 adduct was isolated. By successive addition of imidazole, the displacement reaction takes place, and finally Cu(Im)4 is formed.
A Spectrophotometric Study OE Zirconium Complexes of 4,5‐Dihydroxyfluorescein
Authors: Sun Peng‐Joung , Liu Chuen‐Ying 
Published: June 2015

AbstractZirconium (IV) ions form violet red complex with 4,5‐dihydroxyfluorescein in fairly strong mineral acid medium. The reagent has been successfully applied as a metal indicator in the direct EDTA titration of zirconium.The complex formed by 4,5‐dihydroxyfluorescein and zirconium ions has been studied spectrophotometrically in 0.1M HCl solution. It is found that when an excess of metal ion is present, a violet red colored complex with metal‐ligand ratio of 1:1, (MR) is formed and when an excess of 4,5‐dihydroxyfluorescein is present a 1:2 complex (MR2) may be predominant. The 1:1 complex has maximum absorption at 510 mμ and the 1:2 complex has very low solubility and tends to precipitate out from the solution. Job's method, log‐ratio method and gravimetric method were used to establish the composition of complexes. The apparent stability constant of the 1:1 complex is found to be log Kh = 4.46 or Kh = 2.9×101 at pH 1.2.
Potentiometric Study of the Chelates of Al(III), Ce(IV) and Th(IV) with Alizarin Red S
Authors: Govil Pradip K. , Banerji Samir K. 
Published: June 2015

AbstractThe stepwise metal‐ligand stability constants of ARS chelates with Al3+, Ce1+ and Th4+ have been determined by using Bjerrum‐Calvin technique. Various computational methods were used to determine the stability constants. The thermodynamic stability constants were also calculated by determining the stepwise stability constants at various ionic strengths and then by extrapolating to zero ionic strength. The order of stability constants was found to be: Th>Al>Ce.
The Photochemistry of Ketene the Reactions of Methylene with Toluene and P‐Xylene in Vapor Phase (II)
Authors: Ho Shih Yeng , Lee Min‐Pone 
Published: June 2015

AbstractIn the photolysis of ketene with toluene in the vapor phase, ethylbenzene, xylenes, 2‐methylcycloheptatriene‐1, 3, 5, and three unidentified compounds are found as the products of the reactions of methylene with toluene. In the ketene‐p‐xylene system, p‐ethyltoluene, 1,2,4‐trimethylbenzene, 1,4‐dimethylcyclohepatriene‐1,3,5, and three unidentified compounds are obtained as the products of the reactions of methylene with p‐xylene. The reaction mechanism is discussed.
Studies on Enolisation of Some β‐Diketones by Spectrophotometric Method
Authors: Taneja A. D. , Srivastava K. P. , Gupta M. C. 
Published: June 2015

AbstractEnolisation of acetoacetanilide (AAAH) acetoacet ortho‐toluidide (AATH), 2, 4‐acetoacetxylidide (AAXH), acetoacet‐ortho‐chloroanilide (CAAAH), acetoacetortho‐anisidide (OAAAH), benzoyl‐acetanilide (BAAH) and benzoyl‐meta‐nitro‐acetanilide (NBAAH) have been studied in different solvents of varying polarities, ranging from chloroform (z=63.2) to methanol (Z=83.6) by ultraviolet spectroscopic methods. The low percentages of enol contents in formamide, dimethylformamide and dimethylsulphoxide, may be due to the formation of charge transfer complexes of these solvents with the diketones. Free energy of tautomerisation has also been calculated. The substituents on the phenyl group attached to the nitrogen have no effect on enolisation.
Studies on the Constituents of Formosan Salvia Plebeia R. Br. (I) On the Flavonoid Components of Salvia Plebeia R. Br.
Authors: Yang Tsang‐Hsiung , Chen Kuo‐Tung 
Published: June 2015

AbstractSalvia plebeia R. Br. is an annual herb of Labiatae and is widely distributed in the central area of Taiwan. It has been used as folk‐medicine for the treatment of hepatitis and tumors.1) From the flavonoid enriched fraction (B) of the alcoholic extracts of this plant, four kinds of flavonoid compound were isolated. Two of these were confirmed as 5,4′‐dihydroxy‐6‐methoxy‐7‐glucosyloxy flavone (I). (homoplantaginin, hispidulin‐7‐glucoside) and 5, 7, 4′‐trihydroxy‐6‐methoxy flavone (II) (hispidulin) on the basis of their spectral, chemical evidences and comparison with authentic samples. The other two were assigned to be 5, 3′, 4′‐trihydroxy‐6‐methoxy‐7‐glucosyloxy flavone (III) (nepitrin, eupafolin‐7‐glucoside) and 5,7,3′,4′‐tetrahydroxy‐6‐methoxy flavone (IV) (eupafolin, nepetin) on the basis of chemical and spectral properties. The flavones, II (hispidulin) and IV (eupafolin), have been shown to have cytotoxic activity against human carcinoma of the nasopharynx carried in cell culture (KB).13)
Spectrophotometry Studies of Uranyl Chelate of 7‐Iodo‐8‐Hydroxyquinoline‐5‐Sulphonic Acid
Authors: Hseu Tong‐Ming , Kuo Kuo‐Nan 
Published: June 2015

AbstractUranyl chelate of 7‐iodo‐8‐hydroxyquinoline‐5‐sulphonic acid (ferron) has been studied spectrophotometrically in aqueous solution at 25° and at an ionic strength of 0.1 M. The formation of this chelate was pH dependent, and the optimum pH range was between 5.4 to 5.9, Its mole ratio of ligand to uranyl ion was found to be 2 to 1 stoichiometry and the stability constant, log K, was determined as 13.32±0.08. By using the wave‐length of 365 mu, determination of trace amount of uranyl ion with the sensitivity of 0.54 γ/cm2 was possible.
Meta‐Nitro‐Benzoylacetanilide as a Reagent for Iron
Authors: Taneja A. D. , Srivastava K. P. 
Published: June 2015

AbstractMeta‐nitrobenzoylacetanilide (NBAA) forms violet coloured chelate Fe(NBAA)2 with Fe (III) in 60% ethanol medium with λmax at 530 nm. The molar absorptivity, sensitivity, effect of diverse ions in spectrophotometric determination of iron, and effect of ionic strength on the stability constant have been investigated. The free energy of formation of the chelate, enthalpy change and the entropy change have also been calculated and are found to be −9.44 kcal/mole, −4.97 kcal/mole and 15.23 e.u. respectively.
Maximum Interaction Model Force Constant Calculation of the Mlx (Co)6‐x Type Molecule
Authors: Chen Cheng , Hsiang Chu‐Chiang 
Published: June 2015

AbstractC—O stretching frequency of inorganic carbonyl molecules is quite characteristic in the vibrational spectroscopy (the IR and Raman). Since such stretching modes are quite different from the skeletal modes, a non‐mechanical coupling model has been proposed by Cotton1). The C—O stretching force constants and their interaction constants may be calculated semiquantitatively from their characteristic frequencies. The trouble is that the number of vibrational frequencies is always less than the number of force constants, whenever a symmetry irreducible representation contains more than one frequency. Cotton suggest that the interaction constants for octahedral type molecule from the dpπ bonding point of view1‐2). Instead of this, a model of maximum interaction between M—C—O bonds is proposed in this paper. Such model not only gives better remedy to the problem of octahedral complexes, but also is useful to solve the normal modes in molecules of trigonal bipyramidal and many other symmetries.
The Reaction of 2‐Methylindole with Pyruvic Acid
Authors: Zee Sheng‐Hsu , Lin Sheng‐Yunn , Fin Tei‐Min 
Published: June 2015

AbstractThe reaction of 2‐methylindole with pyruvic acid was studied. Two products are found to be depending on experimental conditions, including the 2:2 condensation adduct and the 2:1 condensation adduct. The reaction mechanism evidently involves a 1:1 adduct of 2‐hydroxy‐2‐(2‐methylindol‐3‐yl)‐propionic acid as an intermediate.
Synthesis of 4′‐Phenylflavones
Authors: Hsu K. K. , Shi J. Y. 
Published: June 2015

AbstractIn order to study the relationship between structure and activity of flavones, several new 4′‐phenylflavones, 4′‐phenylflavonols, and 4′‐phenylflavanones are synthesized by cyclization of corresponding 4‐phenyl‐2′‐hydroxychalcones with selenium dioxide in hot amyl alcohol, with hydrogen peroxide in cold alkalic ethanol, or with phosphoric acid in hot ethanol, respectively. The 4‐phenyl‐2′‐hydroxychalcones are synthesized by condensation of p‐phenylbenzaldehyde with various 2′‐hydroxyacetophenones in hot methanol under presence of potassium hydroxide.
Studies on the Alkaloids of Formosan Lauraceous Plants. XVI.) Alkaloids of Neolitsea Variabillima (Hay.) Kanehira Et Sasaki
Authors: Lu Sheng‐Teh , Su Tsann‐Long 
Published: June 2015

AbstractThree alkaloids have been isolated from the barks of Neolitsea variabilima (Hay.) Kanehira et Sasaki, and these have been identified with L‐hernovine (XIII), L‐nandigerine (XIV), and L‐N‐methylhernovine (XV) respectively.
Effect of Solvents on the Spectra of Some β‐Diketones
Authors: Taneja A. D. , Srivastava K. P. , Gupta M. C. 
Published: June 2015

AbstractAcetoacetanilide, benzoylacetanilide and their derivatives have been examined in ultraviolet region in a series of solvents covering a broad polarity range e. e. from chloroform (Z, 63.2) to methanol (Z .83.6). Transition energies and oscillator strengths have been calculated and transition energy (ET) has been plotted against Z‐values, a new empirical measurement of solvent polarity. A linear relationship was observed between the transition energy and Z‐values for π → π* and n → π* transitions. These transitions are identified as charge transfer (c‐t) transitions and with the solvents having carbonyl oxygen and sulphur atom a c‐t complex formation has been suggested. Strong electron‐donating substituents on phenyl group of the nitrogen atom also showed a weak to moderate n → π* transitions. These substituents have no influence on the position of the λmax in the same solvent. Stabilization energy of the excited state of these ligands and hence the dipole moments of the excited states have been calculated in comparison with pyridinium iodide. Solvent sensitivities of these ligands have also been calculated.
Alkoxy Derivatives of Tricyclopentadienyl Cerium (IV)
Authors: Kapur Miss Shushma , Multani R. K. , Kalsotra B. L. 
Published: June 2015

AbstractTricyclopentadienyl cerïum(IV) chloride has been treated with various primary and secondary alcohols in benzene medium in the presence of triethylamine to give compounds, (C5H5)3Ce(OR) wherein R may be CH3 C2H3, n‐C2H3, iso‐C3H7, N‐C4H9, iso‐C4H9 and iso‐C3H11. Infrared spectra and some physical characteristics of all these compounds and reported.
An Internal‐Reference Method for Determination of Lanthanum, Cerium and Europium in Monazite Sand by Neutron Activation Analysis
Authors: Pung Tong‐Chuin , Wu Shaw‐Chii , Tsai Hui‐Tuh 
Published: June 2015

AbstractA non‐destructive method was developed for the determination of lanthanum, cerium and europium in monazite sand by neutron activation analysis with gold as the internal‐reference element.Black and yellow monazite sands mined from south Tung‐Sen‐chou of Taiwan were analyzed and compared. The sensitivity and relative error were estimated for each element.
Spectrophotometric Studies on the Chelate Formation between Zirconium(IV) and Chromotrope 2R
Authors: Drupar S. C. , Srivastava K. C. , Banerji Samir K. 
Published: June 2015

AbstractThe composition and stability of the chelate formed between Zr(IV) and chromotrope 2R has been investigated using spectrophotometric methods. The chelate is violet in color and has λmax at 530 nm. The composition, determined by different methods is 1 : 1. The chelate is stable between pH 1.0‐3.0. The value of log K as determined by two different methods are 4.48±0.2 and 4.21±0.1 and the values of free energy of formation are —6.21±0.2 and —5.83±0.1 respectively at 30°C. The system obeys Beer's Law over a concentration range of 2.50 to 20.0 ppm of zirconium. The effective range of photometric determination is 3.50 to 19.05 ppm of zirconium.
Thermodynamics of Lanthanum Fluoride in Aqueous Sodium Perchlorate
Authors: Pan Kuan , Hsin Shu‐Ching , Leee Ming‐Long 
Published: June 2015

AbstractThe solubility‐product constant of LaF,(s) was obtained by potentiometric titration of sodium fluoride with lanthanum perchlorate in sodium perchlorate solutions of various ionic strengths. The limiting value of pKs.p were found to be 17.65 and 17.95 at 20° and 25°C, respectively. Thermodynamic calculation from these values gives δG° =‐102.46 kJ mol−1, δH° = 100.40 kJ mol−1 and δS° = 680.40 JK−1 for the reaction, La+3 (aq)+3F‐(aq)=LaF,(s), and δG° =‐1613.8kJ mol‐1, δH1° =‐1594.0kJ mol−1 and S° =433.1 J K−1 mol−1 for the formation of LaF2,(s) at 25°C. The mean activity coefficients and solubilities of LaF2,(s) in NaCIO4 solution at various ionic strengths at 25°C were evaluated.
Synthesis of N,N2‐Disubstituted DL‐β‐Asparagines as Potential Hypocholesteremics
Authors: Liu Kang‐Chien , Chen Tong‐Bao , Shih Ching‐Yun 
Published: June 2015

AbstractBy the addition of equivalent amount of appropriate amine on the carbon‐carbon double bond of N‐substituted maleamic acids under the influence of pyridine, a number of potential hypocholesteremics, N,N2‐disubstituted DL‐β‐asparagines was prepared. For all N‐alkyl‐ and N‐arylmaleamic acids, the addition proceeded smoothly and resulted in satisfactory yields, but in the cases of N‐heterocyclic analogs, transamidation was observed to occur simultaneously with the addition reactions.
Physico‐Chemical Studies on the Interaction of Surface Active Substances at the Dropping Mercury Electrode in Pulsating Field
Authors: Sharma S. K. , Rema R. 
Published: June 2015

AbstractThe tensammetric measurements indicated an appreciable interaction of o‐cresol with piperidine as well as with triethanolamine in aqueous media. The sharp discontinuities in the mixtures of o‐cresol + piperidine and o‐cresol + triethanolamine at the mole ratio 3:1 for o‐cresol to amine are observed by tensammetric, conductommetric and high frequency measurements. The shift of peak potential as well as increase in the magnitude of peak of the mixture have been utilized in determining the composition of the complexes by tensammetric measurements. The nature of formation of such complexes has been predicted. The nature of such interactions have been investigated by infra‐red studies. The molar ratio of phenol to amine (piperidine and triethanolamine) are also estimated to be 3:1.
Spectrophotometric Determination for Trace Amount of Chloride in Uranium
Authors: Chu Chi‐Fen , Wu Shaw‐Shii 
Published: June 2015

AbstractA simple quantitative method is developed for the determination of trace amount of chloride in uranium without preliminary separation. The reactions are realized by mixing the sample with saturated mercury thiocyanate alcohol solution and 0.325M ferric ion in 5.52M perchloric acid solution. The wavelength 465 mμ is used for the determination of chloride. The interference of uranium is negligible for uranium concentration less than 400 ppm. When uranium concentration ranges from 400 to 1.2×104 ppm, the interference can be calculated based on the constancy of molar absorptivity of uranium solution at wavelengthes 465 mμ and 415 mμ, therefore, a correction can be made for the determination of chloride. Interference of other factors were also investigated.
Reduction of Organic Compounds with Thiourea Dioxide I. Reduction of Aldehydes to Primary Alcohols
Authors: Huang Shui‐Lung , Chen Teng‐Yueh 
Published: June 2015

AbstractBenzaldehyde, 2‐pyridinecarbaldehyde, furfural, and 2‐thiophenecarbaldehyde were reduced to the corresponding primary alcohols in satisfactory yields with thiourea dioxide in ethanolic alkaline solution, but 2‐pyrrolecarbaldehyde, in very low yield. The reduction of p‐dimethylaminobenzaldehyde with the same reagent, however, was found to afford bis(4‐dimethylaminophenyl) methane.
Cobalt Complex of l‐(2‐Quinolylazo)‐2‐Phenanthrol(Co‐Qap) as a Visual Acid‐Base Indicator
Authors: Virmani R. N. 
Published: June 2015

AbstractCobalt complex of 1‐(2‐quinolylazo)‐2‐phenanthrol (Co‐QAP) prepared by refluxing cobalt acetate and QAP in the molar ratio 1:2 has been used as a visual acid‐base indicator. The apparant indicator constant has been found to be 6.35. The solution of the indicator in dioxane is stable for at least fifteen days if stored in a dark coloured bottle, while in a transparent bottle it was found to be stable for eight days.
Preparation of Complexes of Copper(II) Aryl Carboxylates with Diethyl Amine and Dipropyl Amine
Authors: Kumar N. , Kalsotra B. L. 
Published: June 2015

AbstractCopper aryl carboxylates are known to form co‐ordination complexes with various nitrogen donors1‐4). Except copper (II) benzoate5) complexes of other copper (II) aryl carboxylates with secondary amines such as diethyl amine and dipropyl amine are not known. The present communication deals with the preparation of complexes of various copper (II) aryl carboxylates with diethyl amine and dipropyl amine.
Thiotropolone as a Chromogenic Reagent for the Microdetermination of Copper(II)
Authors: Srivastava J. N. , Singh R. P. 
Published: June 2015

AbstractThiotropolone forms a brown water‐insoluble complex with copper(II), extracttable into chloroform and other non‐polar solvents. The 1:2 complex shows maximum absorption at 450 nm and obeys Beer's law upto 4.55 ppm. The sensitivity of the reaction is 0.0046 μg Cu(II)/cm2 for log I0/I=0.001 with molar absorptivity of 1.36×104. The usefulness of the procedure has been enhanced to the determination of copper in various alloys and synthetic mixtures.
Spin‐Spin Interactions of Trapped Radicals Produced in 3‐Methylpentane by Gamma‐Irradiation at 77°K
Authors: Lin D. P. 
Published: June 2015

AbstractEPR microwave power saturation technique has been applied to the systems of radiation‐induced radicals in protiated and wholely deuterated 3‐methylpentane to obtain the information concerning the high local spin concentration and radiation energy deposition mechanism. Evidences of spin‐spin interactions have been given from the studies of isothermal decay of these trapped radicals at 77°K. The annealing of the matrix is shown to have almost no effect on the relaxation times of radicals. The influence of nuclear magnetic moment on the spin‐lattice relaxation process of radicals is revealed and discussed on the basis of experimental results from the deuteration of the compound studied.