bluuebunny/crossref_metadata_2025_split huggingface dataset:
Approximate Self‐Consistent Molecular Orbital Method and Repulsive Bonding of Monocarbocyclic Π System
Authors: Chen Cheng 
Published: June 2015

AbstractZero differential overlap (ZDO) approximation1,2) and the consideration of long range (meta and para bonds etc) bonding are applied in this semiempirical LCAO‐SCF MO method. Effective Huckel type formulation and diagonalization procedure of symmetry adapted analysis simplify the computational procedure as well as give a clear and intuitive localized bonding behavior of the carbocyclic molecules. The long range repulsive bonds are defined and discussed between aromatic and non‐aromatic cases. Such bonds are closely correlated to the rigidity and distortion of ring systems. Benzene is the most stable species among the 6π electron systems, and there will be some new explanation of Dewar resonance structures due to the consideration of long range para repulsive bonds in this work.
Green's Function Determination of Force Constants‐H2O as Example
Authors: Mou Chung Yuan , Chen Tunli 
Published: June 2015

AbstractTreating isotopically substituted molecule as a perturbed system, Green's function for the perturbation are constructed and related to the force field of vibration. By spectral representation, Green's function is diagonalized in the normal coordinates. Then transforming back to the Cartesian coordinates, the Cartesian force constants are generated without solving the secular equation directly. The relations between the internal force constants and the Cartesian force constants ate given and complete internal force field can be obtained. The results for H2O are discussed.
Raman Spectra of Carbohydrates
Authors: Wang I‐Cheng , Ting Chen‐Hanson 
Published: June 2015

AbstractThe Raman spectra of 13 different carbohydrates are investigated by a laser Raman spectrometer. It is found the C—H stretching vibrations around 3000 cm−1 is the best region for qualitative analysis of these compounds. All compounds show an O—H stretching vibration around 3370 cm−1 which was not mentioned by earlier works. Excessive background noise appears in many spectra, probably due to their amorphous stuctures.
Anion Exchange Separation of Rare Earths in Methanol‐Nitric Acid Mixed Solutions I. Study on the Distribution Coefficients and Column Elution Method
Authors: Chen Ying‐Mao , Liao Sun‐Chang 
Published: June 2015

AbstractAnion exchange method for the mutual separation of rare earth was studied in methanol‐nitric acid mixed solutions. For each of rare earth element, the distribution coefficients in different concentrations of nitric acid and also in various compositions of methanol solution were studied with the batch equilibrium method. From these distribution coefficients, elution of rare earth by gradient variation in the compositions of methonal was devised. That is, by keeping constant nitric acid at 2 N acidity and gradiently diluting methanol from its original 80% by volume. Results were satisfactory for the mutual separation of the lighter rare earths, but only fairly for the heavier earths.The secondary metal effect for this anion exchange was also studied in 80% by volume of methanol solution by keeping total concentration of nitrate at 0.8 N. Distribution coefficients were larger than nitric acid with LiNO3 but smaller in the case of NH4NO3 and NaNO3. Despite of these difference in distribution coefficients, no remarkable differences were observed for the separation factors of adjacent pairs.
The Photochemistry of Diazomethane the Reactions of Methylene with Toluene and P‐Xylene in Liquid Phase (I)
Authors: Ho Shih Yeng , Wu J. F. 
Published: June 2015

AbstractThe photochemistry of diazomethane in toluene and p‐xylene solutions was investigated. The reactions of methylene with toluene gave eight products. In the diazomethane p‐xylene solution, p‐ethyltoluene, 1,2,4‐trimethylbenzene, 1,4‐dimethylcyclohepatriene‐1,3,5 and three unidentified compounds were found as products of the reaction of methylene with p‐xylene. The relative rates of addition and insertion reaction of methylene with toluene and p‐xylene have been calculated.
A Kinetic Study on the Reduction of Cyanocobalamin with Titanium(III) Chloride
Authors: Pan Kuan , Hsu Ming‐Ta 
Published: June 2015

AbstractThe reaction rate for the reduction of cyanocobalamin (B12) with Ti(III) in HCl and KCl solutions at constant ionic strength was followed by spectrophotometric measurements at 15°, 20°, 25° and 30°C. The reaction rats was found to be of pseudo‐first‐order with respect to B12 and of second‐order with respect to B12 and Ti(III) in HCl solutions. The second‐order rate constant was given by for the processes, The values of K0 obtained were 0.80∼1.29 liter mole−1 sec−1 in the range of ionic strength 0.2∼0.5 M at 30°. The average activation energy was 20.5 kcal mole−1.
Electrometric Behavior of Tetraphenylboron on Mercury
Authors: Lin Zui‐Feng , Li Ting‐I 
Published: June 2015

AbstractElectrometric behavior of tetraphenylboron (TPB) on mercury electrode was investigated, Potentiometric titration of Hg2++ with TPB− showed that TPB− reacted with Hg2++ with stoichiometric ratios (equivalent) of 1:3 and 1:8 (TPB: Hg2++) to form diphenylmercury, Hg(C6H5)2, and phenylmercuric ion, C6H5—Hg+. Only 1:3 stoichiometry was found in the reverse titration. Potential response of TPB− on mercury assumed the same result, and furthermore, if the concentration of TPB− was around 10−3 M or higher, another stoichiometry of 1:1 with formation of Hg(I)‐tetraphenylborate might be possible. Controlled potential oxidation of TPB− on mercury gave Hg(C6H5)2 and C6H5Hg+ which were identified by m. p. measurements and elementary analyses.
The Photochemistry of Diazomethane the Reaction of Methylene with Ammonia and Methylamine
Authors: Ho Shih‐Yeng , Tong Shen‐Nan 
Published: June 2015

AbstractIn the photolysis of diazomethane in the presence of ammonia, the ratio of the products, [CH3NH2/[C2H4], has been studied as a function of pressure, temperature and composition of diazomethane‐ammonia mixture, respectively. This ratio increases with increase in total pressure at low pressures and approaches a constant at high pressures.In the diazomethane‐methylamine system, the ratio of products, [CH3CH2NH2]/[(CH3)2NH], is independent of the pressure in the range from 23 to 500 torr. The rates of insertion of singlet methylene into C–H bond and N–H bond of CH3NH2 are found to be about the same.
Studies on the Preparation and Properties of Some Phenolic Derivatives of Tricyclopentadienyl Cerium (IV) and Bisindenyl Cerium (IV)
Authors: Kapur (Miss) Shushma , Kalsotra B. L. , Multani R. K. 
Published: June 2015

AbstractReactions of tricyclopentadienyl cerium (IV) chloride (I) and bisindenyl cerium (TV) dichloride (II) with mono‐, di‐, and trihydroxy phenols have been studied and some phenoxide derivatives of (I) and (II) have been isolated. Infrared spectra and some physical characteristics of all these compounds are Reported.
Para‐Conjugation in Aromatic Systems and the Correlation between Mo Bond Order and the Resonance Structures Cheng
Authors: Chen Chen 
Published: June 2015

AbstractA simple correlation between the MO bond orders and the resonance structures of a π system is proposed. Para conjugation is a resonance structure with parallel arrangement of alternating attractive and repulsive bonds. The results in C5H5−, C6H6 and C77+ clearly show that the para conjugation is very important comparing with the ordinary ring conjugation. The aromatic substitution reactions strongly demomstrates the effect of para conjugation in benzene, naphthalene and anthrance.
The Photochemistry of Diazomethane the Reactions of Methylene with Methanol and Ethanol
Authors: Ho Shih‐Yeng , Lin Horn‐Bond 
Published: June 2015

AbstractIn the photolysis of diazomethane‐methanol. mixture, the reaction of methylene with methanol gives dimethyl ether and ethanol as products. The ratio of dimethyl ether to ethanol is found to be independent to pressure and to. the composition of diazomethane‐methanol mixture. Methylene insertion into O—H bond is about 11 times faster than that into C—H bonds of methanol. The ratio decreases with increase of temperature.In the diazomethane‐ethanol system, ethylmethyl ether, propanol‐1 and propanol‐2 are found as the products of insertion reaction of methylene into ethanol. The ratios of ethylmethyl ether to propanol‐1 and to propanol‐2 are both found to be almost constant and independent to pressure and to the composition of diazomethane‐ethanol mixture. A small temperature effect on the ratios are observed. The rate of insertion of methylene into O—H bond is about 7.3 and 14.2 times faster than those into primary and secondary C—H bonds of ethanol, respectively.
Photoaddition of Iodoform to P‐Chlorostyrene and Indene
Authors: Lin Lung‐Ching , Hsu Ying‐Gev , Wamg Ching‐Bore 
Published: June 2015

AbstractA new type of triiodo compounds synthesized by irradiation of p‐chlorostyrene or indene with iodoform in the inert solvent is reported.
Two New Saturated Sesquiterpene Diols—Cadinan‐3β, 9β‐Diol and Cadinan‐3β, 9α‐Diol from Taiwania Cryptomerioides Hayata
Authors: Kuo Y. H. , Cheng Y. S. , Kao S. T. , Lin Y. T. 
Published: June 2015

AbstractFrom the wood of Taiwania cryptomerioides Hayata, two new sesquiterpenes, cadinan‐3β, 9β‐diol and cadinan‐3β, 9α‐diol were isolated as minor components. Their structures were elucidated as (I) and (II), respectively.
Normal Coordinate Analysis in Cartesian Space I. Planar Symmetric Xn Molecules
Authors: Ting Chen‐Hanson 
Published: June 2015

AbstractNormal coordinate analysis of Xn type molecules can be carried out in the Cartesian space as well as in the internal space. Force constants in Cartesian coordinates for aromatic compounds belonging to Dnh group are calculated. The force constants of benzene are evaluated from vibrational frequencies both in the ground state and the 1B1u excited state.The calculated frequencies of planar carbon vibration of annulene of any N are tabulated. The normal coordinates derived from the calculation of 10‐annulene are roughly the same of naphthalene derived more elaborated by Scherer. The normal modes in 10‐annulene are indeed good approximations to the ones in naphthalene. This conclusion is valid for the other aromatic compounds.
The Mass Spectrometry of Some Bis (Trimethylsiloxy)Naphthalenes
Authors: Wang Ching‐Bore , Lin Lung‐Ching , Liu Sheng‐Lith 
Published: June 2015

AbstractMass spectrometric data were reported for 1,4‐; 1,5‐; 1,6‐; 1,7‐ and 2,6‐bis(trimethylsiloxy)naphthalenes. By the use of metastable‐ion measurement the major fragmentation pathways of the five compounds have been deduced. The doubly charged ion and ion‐molecule‐reaction ion were also discussed.
Correlation of Mössbauer and Radiochemical Data on Hexacyanoferrates(II)
Authors: Lee Y. J. , Chen J. W. , Huang C. H. , Yeh S. J. , Cheng H. S. 
Published: June 2015

AbstractMössbauer spectra of K4Fe(CN)6 and K4Fe(CN)6 3H2O, observed 3 weeks after irradiation, did not differ from the unirradiated samples, which implied that there was no change in oxidation state of iron. The fresh aqueous solutions of these irradiated samples also did not show any change in the oxidation state. Fe(OH)3 separated in chemical treatment was time dependent and was further influenced by the chemical reagents.
Correlation of Mössbauer and Radiochemical Data on Hexacyanoferrate(III)
Authors: Lee Y. J. , Chen J. W. , Huang C. H. , Yeii S. J. , Cheng H. S. 
Published: June 2015

AbstractMössbauer spectra of irradiated K1Fe(CN)6, observed 3 weeks after irradiation, showed that 3% of iron was converted to Fe(CN)64−, while chemical analysis performed 100 hours after irradiation showed 18% was reduced to Fe(CN)64−, Prussian blue was isolated in the chemical analysis, but not observed in the Mössbauer spectra. The Prussian blue formation was found to be time dependent.
Thermometric Studies of Multi‐Valent Metal Complexes
Authors: Hsin Shu‐Ching , Huang Teh‐Shoon 
Published: June 2015

AbstractThermometric titrations of lanthanum perchlorate, titanium (III)‐chloride, uranium (IV)‐sulfate, and uranyl sulfate with EDTA solutions were carried out by using a Keithley nanovoltmeter with a rhodium‐platinum thermocouple at 25°±0.01°. The formation of LaY−, TiY−, U(IV)Y and UO2HY− ions was confirmed. The heat of reaction for the system, Ti(III)+H2Y2− = TiY−+2H+, was given by δH1 = 1.933‐1.422×10 m +2.056×104m (in cal) and the limiting value was evaluated to be δH°1 = 1.9 kcal mol−1 at 25°C.
NMR Study of Some Sesquiterpene Alcohols and Their Oxidation Products
Authors: Lin Y. T. , Cheng Y. S. , Kuo Y. H. , Lin K. C. 
Published: June 2015

AbstractOxidations of α‐cadinol, T‐cadinol, T‐muurolol and δ‐cadinol with SeO3 gave corresponding ketols and diols. Reductions of the ketols with NaBH4 gave epidiols. NMR data of these sixteen compounds are compared.
3‐Nitroso‐4‐Hydroxy‐5,6‐Benzocoumarin as a Specific Reagent for the Detection of Iron in Microamounts
Authors: Kohli Nitin , Garg B. S. , Singh R. P. 
Published: June 2015

AbstractComplexation of 3‐nitroso‐4‐hydroxy‐5, 6‐benzocoumarin with iron (II) is used to detect iron in presence of various ions present in the scheme of semi‐micro qualitative analysis. The method finds application in detection of iron in alloys, inorganic salts and various pharmaceutical products.
A Thermodynamic Study of Chromotropico‐Titanium(III) Complex from Spectrophotometric Measurements
Authors: Pan Kuan , Liang Yu‐Lon 
Published: June 2015

AbstractThe formation of 1 : 2 titanium(III) complex with chromotropic acid (4, 5‐dihydroxy‐2, 7‐naphthalene‐disulfonic acid) was observed by spectrophotometric measurements at various ionic strengths. An expression, [Ti(III)]/D=1/Δϵ + αH2+/KΔϵ[H2R2−]2, was derived for the determination of the formation constant, K=7.2×102 liter2 mol−2 for the Ti(III).(HR)2 ion in the pH range of 1.3–1.8 at constant ionic strength, I=0.2 M, at 25°C. The thermodynamic data for the reaction, Ti(III)+2H3R2−=Ti(III) (HR)2+2H+, were calculated to be ΔG° = −16 kJ mol−1 ΔH° = 18 kJ mol−1, ΔS° = 110 JK−1 mol−1, at 25°C.
Mössbauer Studies of Radiation Effect on Pentacyano Complexes of Iron
Authors: Huang C. H. , Cheng H. S. 
Published: June 2015

AbstractMössbauer and ir spectroscopies have been applied to the study of radiation effect on Fe11X(CN)3 (X=NO+, NH3, H2O, NO2−, SO3=) and Fe111X(CN)3 (X=NH1, H2O, NO2−). Fe(II) complexes were not oxidized to Fe(III), whereas Fe(III) complexes were reduced to Fe(II). Na2[FeNH3(CN)3]·H2O was partially reduced at 7 hour irradiation, but [FeNO(CN)2]= was obtained at the longer irradiations due to the replacement of H by O produced by water radiolysis.
Essential Oils XVI Oil of Eryngium Foetidum, Linn.
Authors: Yeh Ping‐Hsien 
Published: June 2015

AbstractThe oil of Eryngium foetidum, Linn. consists 9.06% of acid part and 90.94% of neutral part. The constituents are 4.80% lauric acid, 2.09% 3, 4‐dimethylbenzoic acid, 1.17% capric acid, 1.00% of an unidentified acid (p‐bromophenacyl ester m. p. 68°), 2.59% α‐pinene, 2.26% p‐cymene, 1.88% decanal, 72.73% of a mixture of 2, 4, 5‐trimethylbenzaldehyde, 5‐dodecanone and 4‐hydroxy‐3, 5‐dimethylacetophenone, 10.16% sesquiterpene ketone, and 1.32% others.
Electron Spin Resonance of Trapped Radicals and the Photoinduced Radical Conversion in γ‐Irradiated 3‐Methylpentane Glasses at 77°K
Authors: Lin D. P. 
Published: June 2015

AbstractStudies on the isotropic hyperfine splitting constants of protiated and deuterated 3‐methylpentyl radicals produced by γ‐ray accompanied with the radical yield determinations reveal that the radicals are distributed in clusters in the matrix. A tentative mechanism with the migration of positive hole is proposed for the formation of UV‐induced new radicals following γ‐irradiation in 3‐methylpentane glasses at 77°K; and to account for all the experimental observation.
The Reaction of Ethyl Bromoacetate with Dimethyl Sulfoxide
Authors: Tien J. M. 
Published: June 2015

AbstractThe reaction of excess dimethyl sulfoxide with ethyl bromoacetate has been shown to produce ethyl glyoxylate, hydrogen bromide, and dimethyl sulfide. The yield of glyoxylate at first was reduced because the dimethyl sulfide reacted with bromoacetate to form trimethylsulfonium bromide and ethyl (methylmercapto) acetate, presumably via carbethoxymethyldimethylsulfonium bromide. These side reactions were diminished in a thin‐film reactor, but the result was not satisfiable, the yield was 51%, and the side reactions were prevented by addition of methyl bromide, which rapidly consumed the dimethyl sulfide with formation of trimethylsulfonium bromide. Addition of 1, 2‐epoxy‐3‐phenoxypropane removed the hydrogen bromide, thereby preventing the deleterious effects casued by its reduction of dimethyl sulfoxide to dimethyl sulfide. In this way has been developed a convenient preparation of ethyl glyoxylate in yields averaging about 70%. Identification and stoichiometry of the reaction products are presented.
Qualitative Analyses of Coins by Using a Si(Li) Detector and An Xrf‐Exciter System
Authors: Yang Huai‐Tung , Ting Chen‐Hanson 
Published: June 2015

AbstractX‐ray fluorescence spectra of many coins are studied using a Si(Li) detector and an XRF‐exciter system. Some qualitative and semiquantitative analyses have been carried out. It is demonstrated that this method can be a very powerful means to study the archaeology of metal objects, especially the copper alloys, such as coins and bronze vessels.
Studies on the Components of Formosa Cirsium Species Part II Components of Cirsium Arisanense Kitam
Authors: Lin Chun‐Nan , Chang Cheng‐Hsiung , Wu Tian‐Shung 
Published: June 2015

AbstractFrom the fresh leaves of Cirsium arisanense Kitam (Compositae), a flavone glycoside, pectolinarin (II) and an unsaturated dibasic acid, fumaric acid (III), were isolated.
Solvent and Substituent Effects on the Spectra of Some Substituted Thioureas
Authors: Kashyap B. C. , Banerji Samir K. 
Published: June 2015

AbstractA study on the effect of a number of solvents, covering a broad polarity range i.e. from dioxane (D=2.20) to acetonitrile (D=38.0), has been made on the electronic transitions of N‐aryl, N′‐2‐(5‐halo‐pyridyl) thioureas (where aryl= ‐C2H5 or O‐CH3‐C6H5‐, and halo= ‐Cl, ‐Brand ‐I). Two intense absorption maxima in the regions 270‐285 nm (assigned for thiocarbonyl π‐π* transition) are exhibited by all the substituted thioureas studied. The excitation energies and oscillator strengths of these transitions have been calculated. A correlation between ‘ET’ and ‘Z’ (an empirical measure of solvent polarity) has been attempted. Solvent sensitivities of these compounds have also been calculated.The effect of halo‐substituents, in the pyridine ring, on the spectra of these substituted thioureas has also been studied. It has been proposed that there is a delocalization of electrons between the pyridine ring and the thiourea unit of these compounds. This delocalization of electronic charge is affected by the substitution of the halo‐groups in the pyridine ring at para position to the thiourea unit which is reflected in the intensities and shifting of the absorption maxima.
Spectrophotometric Determination of Iridium (IV) with 3‐Nitroso‐4‐Hydroxy‐5, 6‐Benzocoumarin
Authors: Kohli Nitin , Kohli R. M. , Singh R. P. 
Published: June 2015

AbstractIridium(IV) gives a deep red complex with 3‐nitroso‐4‐hydroxy‐5,6‐benzo‐coumarin when heated on a boiling water‐bath for about 10 minutes. The complex is soluble in 50% aqueous acetone medium and exhibits maximum absorption at 520nm. Beer's law is obeyed up to 10.5 ppm of iridium at 520 nm. Molar absorptivity is 1.28×104 litre mole‐1 cm‐t and the sensitivity of the colour reaction is 0.015 μg Ir(IV)/cm2. The composition of the complex is 1:3 as determined by Job's and logarithmic methods. Common anions and cations do not interfere in the determination.
Electron Paramagnetic Resonance Study of Radical Pairs and Isolated Radicals Trapped in Irradiated Long‐Chain Hydrocarbons at Low Temperatures
Authors: Lin D. P. , Fan Kuo Wei , Yeh Si‐Jung , Chen Grace M.S. 
Published: June 2015

AbstractThe intrinsic characteristics of radical pairs produced in squalane and in cetane receiving high gamma‐dose are extensively studied with the EPR technique at temperatures from 77°K up to 150°K. The spectra of the paired radicals occur at g=4 with a very low transition probability in contrast to that of isolated radicals which appear at g=2 A well‐resolved hyperfine spectrum corresponding to the species (CH3CH2.CH2CH3) is observed in cetane. The isothermal decay rates of radical pairs in cetane below 100°K are significantly slow; however, the decay kinetics at 150°K is first order with rate constant=1.86 min−1. A relatively slower decay rate is obtained for isolated radicals suggesting that the decay mechanism of paired radicals is through geminate recombination. The relative inter‐radical distance in radical pairs is known from a decay curve as a function of temperature. The yields of radical pairs are low in both matrices, only few percents of those of isolated radicals. The formation mechanisms of paired radicals with direct radiolytic bond scission process are discussed in connection with the experimental observations.
Synthesis of N‐Substituted Maleimides as Potential Antineoplastic Sulfhydryl Agents
Authors: Liu Kang‐Chien , Jan Hon‐Ji 
Published: June 2015

AbstractFor a purpose of antineoplastic screening, a series of sulfhydryl‐binding agents, N‐substituted maleimides was prepared. These compounds were obtained by dehydration of the corresponding maleamic acids under suitable conditions in which the formation of maleisoimide by‐products was prevented, IR and UV spectra, as well as the elemental analyses confirmed the structural assignment of our products, A brief discussion on the preparation of N‐(2,4‐dinitrophenylamino)maleimide was also given.
Studies on Salicylate Complexes of Lanthanum
Authors: Koul M. L. , Kachroo P. L. 
Published: June 2015

AbstractStoichiometric determination of complexes of La (III) with some derivatives of salicylic acid by monovariation and Job's method of continuous variation have shown formation of 1:3 complex in each case. The dissociation constants of these complexes have been determined by conductometric and spectrophotometric methods.
3,4‐Bis(Trialkylsiloxy)Toluenes
Authors: Ho Chin‐Hsia 
Published: June 2015

AbstractThree stable new compounds, 3,4‐Bis(trimethylsiloxy)toluene, 3,4‐Bis(triethylsiloxy)toluene and 3,4‐bis(tri‐n‐propylsiloxy)toluene have been synthesized and characterized by their analytical data, molecular weights, infrared and nuclear magnetic resonance spectra.
Physicochemical Studies on Cu(II)‐Ferron Complexes
Authors: Lin Zui‐Feng , Chiang Yueh‐Er , Chin Shain‐Hsin 
Published: June 2015

AbstractExperiments were carried out at 25°C and μ of 0.1 M. Spectrophotometric and potentiometric methods gave the ionization constants of ferron, pK1=2.50±0.02 and pK2=7.12±0.02. Cu(II) and ferron form a sparingly soluble 1:1 complex, [Cu(H2O)2L]0 (L: ferronate ion) which in higher acidity media, protonates to give [Cu(H2O)2HL]+and in lower acidity media, ionizes to give [Cu(H2O)(OH)L]−. At pH 2.3, the 1:1 complex gives a minimum solubility and the intrinsic solubility was found to be 1.1×10‐4. The Job's continuous variation method and the molar ratio method gave a formation constant (–pK) for Cu2++Lz−⇌CuL, 10.8±0.1 in the pH range of 0.64 to 1.18 and in the pH range of 5.0 to 5.5 (optimum pH condition for formation of complex), the stoichiometry of the Cu(II)‐ferron chelate is essentially 1:2 (Cu:L) but with slight tendency to form 1:1 chelate if [L]/[Cu] is less than 2. The overall formation constant (–pK) was determined to be 20.0±0.3.