bluuebunny/crossref_metadata_2025_split huggingface dataset:
NMR Study of Hetero‐Association Accompanying Self‐Association of 2‐Hydroxyl‐4‐methyl‐pyridine and 2‐Pyrrolidone in Acetonitrile
Authors: Luo Wei‐Chen , Lin Chi‐Chyuang , Lin Juh‐Ann , Dah‐YuKao  , Chen Jenn‐Shing 
Published: May 2015

AbstractThis work in vestigated not only the equilibrium of self‐association of 2‐pyrrolidone (A) and that of 2‐hydroxyl‐4‐methyl‐pyridine (B), but also the hetero‐association between A and B in [2H3]acetonitrile through hydrogen bonding using high‐resolution nuclear magnetic resonance spectroscopy. Dilution shift data for the protons of the NH group of A and OH group of B were measured over a wide range of temperatures and concentrations. In addition, the monomer shifts, dimer shifts and dimerization constants of self‐association and hetero‐association were evaluated using a graphic method operating on the dilution chemical shift data. The enthalpy and entropy of dimerization of self‐association and hetero‐association were also obtained from the van't Hoff plot.
Properties and Applications of Cryptand‐22 Surfactant for Ion Transport and Ion Extraction
Authors: Hwang Wen‐Yu , Shih Jeng‐Shong 
Published: May 2015

AbstractA non‐ionic cryptand‐22 surfactant consisting of a macrocyclic cryptand‐22 polar head and a long paraffinic chain (C10H21‐Cryptand‐22) was synthesized and characterized. The critical micellar concentration (CMC) of the cryptand surfactant in ROH/H2O mixed solvent was determined by the pyrene fluorescence probe method. In general, the cmc of the cryptand surfactant increased upon decreasing the polarity of the surfactant solution. The cryptand surfactant also can behave as a pseudo cationic surfactant by protonation of cryptand‐22 or complexation with metal ions. Effects of protonation and metal ions on the cmc of the cryptand surfactant were investigated. A preliminary application of the cryptand surfactant as an ion‐transport carrier for metal ions, e.g., Li+, Na+, K+ and Sr2+, through an organic liquid‐membrane was studied. The transport ability of the cryptand surfactant for these metal ions was in the order: K+ ≥ Na+ < Li+ < Sr2+. A comparison of the ion‐transport ability of the cryptand surfactant with other macrocyclic polyethers, e.g., dibenzo‐18‐crown‐6, 18‐crown‐6 and benzo‐15‐crown‐5, was studied and discussed. Among these macrocyclic polyethers, the cryptand surfactant was the best ion‐transport carrier for Na+, Li+ and Sr2+ ions. Furthermore, a foam extraction system using the cryptand surfactant to extract the cupric ion was also investigated.
Rate Study of Proton Catalyzed SmI2 Reduction of 2‐Heptanone and 1,2‐Epoxydecane
Authors: Lin Tzuen‐Yeuan , Fuh Ming‐Ren , Lin Yu‐Sheng , Wen Chang‐Rong , Lin Jia‐Yung , Hu Chiao‐Ling 
Published: May 2015

AbstractRate constants directly measured from the GC‐analyzed method for SmI2 reduction of 2‐heptanone and 1,2‐epoxydecane in the presence of various proton sources were obtained. Water exhibits much stronger catalytic effect than methanol and t‐butanol. Dependence of reaction rates on concentration of SmI2 and temperature were studied.
Alkaloids from the Leaves of Fissistigma Glaucescens
Authors: Lo Wen‐Li , Chang Fang‐Rong , Wu Yang‐Chang 
Published: May 2015

AbstractTwo new alkaloids, glaucenamide (1) and fissiceine (2), along with fifteen known ones, liriodenine (3), oxocrebanine (4), kuafumine (5), oxoxylopine (6), atherospermidine (7), (‐)‐xylopine (8), (‐)‐N‐acetylxylopine (9), N‐trans‐feruloyltyramine (10), aristololactam BII (11), aristololactam BIII (12), aristololactam AII (13), piperolactam A (14), goniothalactam (15), norcepharadion B (16), and noraristolodione (17) were isolated from the methanolic extracts of the Fissistigma glaucescens. The structures of these compounds were established by means of spectral analysis.
Utility of (p‐Sulfonamidophenyl)azomalononitrile, and Ethyl Acetoacetate in Synthesis of Fused Azole and Azines Derivatives II
Authors: Hassanien A. A. , Amr A. E. , Ghozlan S. A. S. 
Published: May 2015

Abstract[(p‐Sulfonamidophenyl)azo]malononitrile (1a,b) reacted with N‐cyclohexanemethylidene‐2‐cyanoacetohydrazide, N'‐arylmethylidene‐2‐cyanoacetohydrazide (3a‐c), S‐methylthiourea and hydrazine hydrate to afford [1,2,4]triazolo‐[1,5‐a]pyridinone derivatives (2a,b) & (4a‐c), substituted pyrimidines 5a,b and 6a,b. The corresponding pyridazinones 7a,b were synthesized from the reaction of 1c,d with ethyl cyanoacetate. Compound 7a,b reacted with elemental sulfur to yield 8a,b. Compound 6a underwent cycloaddition with α‐cinnamonitrile 9a‐e to yield 11a‐c, 14 and 15. Also, compound 6a reacted with β‐ketoester and 1,3‐diketones to give 16, 17 and 18.
Density Functional Study on the Reactivity of Carbenes Toward 1,2‐H Shifts
Authors: Hu Ching‐Han 
Published: May 2015

AbstractThe 1,2‐H shift reactions of simple carbenes (CH2Y‐C‐X) have been studied using density functional theory (DFT). The influence of the substituent X and Y groups on the activation energy (Ea) of 1,2‐H shifts were examined. The ‘by stander’ Y substituents lower Ea in the order of Me, F > Cl, Br > H. Our analysis shows that the X effect is more significant than the by stander Y effect. X substitutions increase Ea of carbenes in the order of F > Cl > Br > Me > H. The influence of X on Ea is governed by the singlet‐triplet energy separation (ΔES‐T) of the carbene, i.e., Ea of a carbene is larger as its ΔES‐T in creases due to an X substitution. The X effect was also found to be related to the magnitude of the exothermicity: Ea of reaction is smaller when the reaction is more exothermic. Origin of the Y effect is attributed to the inter play between two factors: ‘lateness’ of transition state on the potential energy surface, and the exothermicity of the reaction.
Synthesis and Spectroscopy of Novel‐α‐Pyrazolylglycine Derivatives
Authors: Zia‐Ul‐Haq Muhammad , Arshad Muhammad , Saeed‐ur‐Rehman  
Published: May 2015

AbstractThe synthesis of α‐pyrazolylglycine derivatives(7a‐d) with different substituents, starting from glycine have been pre pared. The spectroscopy of intermediate compounds and the final amino acids have been discussed.
Total Synthesis of (±)‐Eusiderin G and (±)‐Eusiderin M
Authors: Jing Xiaobi , Gu Wenxin , Ren Xinfeng , Bie Pingyan , Pan Xinfu 
Published: May 2015

Abstract(±)‐Eusiderin G and (±)‐Eusiderin M were first synthesized from pyrogallol, in which the Claisen Rearrangement was used to afford two important C6‐C3 units.
Solvent‐Free Synthesis of Heterocyclic Thioureas Using Microwave Technology
Authors: Li Jian‐Ping , Luo Qian‐Fu , Wang Yu‐Lu , Wang Hong 
Published: May 2015

AbstractA new and rapid solvent‐free synthesis of heterocyclic thioureas in a microwave oven has been reported for the first time. Nine heterocyclic thioureas that possess biological activity have been synthesized. The reaction time is short (2–4.5 min) and gives excellent yields (82.9–95.5%).
A New Route to N‐Aryl 2‐Alkenamides, N‐Allyl N‐Aryl 2‐Alkenamides, and N‐Aryl α,β‐Unsaturated γ‐Lactams from N‐Aryl 3‐(Phenylsulfonyl)propanamides
Authors: Wang Eng‐Chi , Huang Keng‐Shiang , Lin Gwo‐Woei , Lin Jia‐Ruei , Hsu Ming‐Kun 
Published: May 2015

AbstractA series of N‐aryl 2‐alkenamides were produced efficiently by treating N‐aryl 3‐(phenylsulfonyl)‐propanamides with potassium tert‐butoxide in THF at 0°C. With out isolation, it was further treated with an additional equivalent of potassium tert‐butoxide and allyl bromide to give N‐allyl N‐aryl 2‐alkenamides in one pot in good yields. Followed by a ring‐closing metathesis reaction, these N‐allyl N‐aryl 2‐alkenamides were respectively converted into corresponding N‐aryl α,β‐unsaturated γ‐lactams in moderate yields.
Studies on Fused Azoles: Synthesis of Several Polyfunctionally Substituted Fused Azoles
Authors: Raslan M. A. , El‐Aal R. M. Abd , Hassan M. E. , Ahamed N. A. , Sadek K. U. 
Published: May 2015

AbstractThe synthesis of several new polyfunctionally substituted fused pyrazoles via reaction of 5‐amino‐3‐methylthio‐1H‐pyrazole‐4‐carboxylate (2) with different reagents is described.
Phenolic Compounds from Formosan Euphorbia tirucalli
Authors: Lin Shwu‐Jiuan , Yeh Chang‐Ho , Yang Li‐Ming , Liu Pang‐Chun , Hsu Feng‐Lin 
Published: May 2015

AbstractFourteen polyphenolic compounds were isolated from the 60% aqueous acetone extract of Formosan Euphorbia tirucalli L. (Euphorbiaceae). Two compounds, 5‐desgalloylstarchyurin and 3,3′,4‐tri‐O‐methyl‐4′‐O‐rutinosyl ellagic acid, were deduced by concerted application of 1D and 2D NMR methods, and reassigned their NMR data.
The Constituents of Aristolochia elegans and Aristolochia zollingeriana
Authors: Wu Tian‐Shung , Leu Yann‐Ln , Tsai Yao‐Lung , Lin Fu‐Wen , Chan Yu‐Yi , Chiang Chia‐Yu 
Published: May 2015

AbstractContinuing our investigation on the bioactive compounds from the plant of the Aristolochia genus in Taiwan, we isolated one new sesquiterpene, aristololide, from the stem and roots of A. elegans, eleven known compounds from the fruits of A. elegans and nine known compounds from the fresh leaves of A. zollingeriana. Their structures were elucidated according to the 1D and 2D NMR spectroscopic analyses or by comparison with literature values.
Transformation of Ginsenosides Rg1 and Rb1, and Crude Sanchi Saponins by Human Intestinal Microflora
Authors: Lin Mei‐Chih , Wang Kuang‐Chao , Lee Shoei‐Sheng 
Published: May 2015

AbstractFractions major in ginsenosides Rg1 and Rb1 from Sanchi saponins were transformed by human fecal flora. This study yielded the corresponding aglycone, protopanaxatriol, in 49.4% from Rg1, protopanaxadiol 20‐O‐glucoside in 54.8% from Rb1, and dihydroprotopanaxadiol 20‐O‐glucoside in 87.6% from dihydro Rb1, by incubation with healthy feces for 70 h in subgram level. Never the less large‐scale incubation of crude Sanchi saponins revealed the complete biotransformation of Rb1 and the almost unchanged Rg1. A small amount of Rg1 was found to be converted into 20 R‐ginsenoside Rh1 and its dehydration product, 20(22) Z‐ginsenoside Rh4.
Synthesis and Antifungal Activities of ω‐[4‐Aryl‐5‐(1‐phenyl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐1,2,4‐triazol‐3‐thio]‐ω‐(1H‐1,2,4‐triazol‐1‐yl)acetophenones
Authors: Chu Chang‐Hu , Hui Xin‐Ping , Zhang Yan , Zhang Zi‐Yi , Li Zhi‐Chun , Liao Ren‐An 
Published: May 2015

AbstractNew 4‐aryl‐5‐(1‐phenyl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐1,2,4‐triazol‐3‐thiones 3 have been synthesized by the intramolecular cyclization of 4‐aryl‐1‐(1‐phenyl‐5‐methyl‐1,2,4‐triazol‐4‐formyl)thiosemicarbazides 2 with an 8% NaOH solution, and then 3 reacted with ω‐bromo‐ω‐(1H‐1,2,4‐triazol‐1‐yl)acetophenone to afford ω‐[4‐aryl‐5‐(1‐phenyl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐1,2,4‐triazol‐3‐thio]‐ω‐(1H‐1,2,4‐triazol‐1‐yl)‐acetophenones 4. The preliminary biological test showed that the representative compounds possess some anti fungal activities.
A Comparative Study of Hydrogen Bonding Using Density Functional Theory
Authors: Lai Chun‐Chia , Shen Chien‐Chern , Hu Ching‐Han 
Published: May 2015

AbstractThe hydrogen‐bond energies of water dimer and water‐formaldehyde complexes have been studied using density functional theory (DFT). Basis sets up to aug‐cc‐pVXZ (X=D, T, Q) were used. It was found that counterpoise corrected binding energies using the aug‐cc‐pVDZ basis set are very close to those predicted with the aug‐cc‐pVQZ set. Comparative studies using various DFT functionals on these two systems show that results from B3LYP, mPW1PW91 and PW91PW91 functionals are in better agreements with those predicted using high‐level ab initio methods. These functionals were applied to the study of hydrogen bonding between guanine (G) and cytosine (C), and between adenine (A) and thy mine (T) base pairs. With the aug‐cc‐pVDZ basis set, the predicted binding energies of base pairs are in good agreement with the most elaborate ab initio results.
The Synthesis of N‐(Glycosylthioureylene)‐aminothiophosphonic and ‐diaminothiophosphinic O‐aryl Esters
Authors: Cao Ling‐Hua , Zhou Chuan‐Jian , Gao Hong‐Yun , Liu Yu‐Ting 
Published: May 2015

AbstractReactions of O‐aryl dihydrazinothiophosphinates (4, 5) or O,O′‐diarylhydrazinothio‐phosphonates (2) with glycosyl isocyanates (6) gave corresponding N‐(glycosylthioureylene)‐aminothiophosphonic and ‐diaminothiophosphinic O‐aryl esters. Their structures were confirmed by IR, 1H NMR, 31P NMR, MS and elemental analyses.
The Reaction Studies of α‐Chloroformylarylhydrazines with Thiols, Thioureas and α‐Cyclodiketones
Authors: Kuo Wen‐Fa , Wu Ming‐Shyue , Chiu Chun‐Yen , Yeh Mou‐Yung 
Published: May 2015

AbstractThe reactions of α‐chloroformylarylhydrazines 1 with various types of mercaptan, thiourea and α‐cyclodiketone have been studied intensively. 1‐Arylhydrazinecarbothioates 2 were obtained via thioesterization when α‐chloroformylarylhydrazines reacted with thiols. On the other hand, compounds 3 were obtained when α‐chloroformylarylhydrazines reacted with thio‐containing heterocyclic compounds, which suggested a totally different mechanism in these types of reactions. Further studies on the reaction of α‐chloroformylarylhydrazines 1 with thiourea compounds confirmed a novel cyclization and de‐cyclization mechanism, which led to give 2‐arylhydrazinecarboximidamides 5 and 1,3,4‐thiadiazolin‐5‐ones 6. In addition, various 1,3,4‐oxadiazines 9 were obtained by reacting α‐chloroformylarylhydrazines with α‐cyclodiketones, showing ring cyclization was involved in this type of reaction.
Ptychantins from the Liverwort Ptychanthus Striatus
Authors: Wu Chia‐Li , Wang Chien‐Jen , Yin Ming‐Horng 
Published: May 2015

AbstractFive new ptychantins, J‐N, along with two known ones, G and I, were isolated from the liverwort Ptychanthus striatus. Their structures were established by NMR spectroscopic analyses.
Rydberg and Doubly Excited States of Na2 and Li2
Authors: Li Li , Liu Yaoming , Lyyra A. Marjatta 
Published: May 2015

AbstractRydberg and doubly excited states of Na2 and Li2 have been studied by optical‐optical double resonance (OODR) excitation spectroscopy. In this short review article we summarize the Rydberg states and doubly excited valence states of Li2 and Na2 that have been observed experimentally. We also give experimental evidence for the electronic characteristic differences between these two types of electronic states observed in our experiments.
Present Status of Highly Charged Ion Experiments with an ECR Ion Source at TMU
Authors: Tanuma Hajime , Matsumoto Jun , Nishide Tatsuhiro , Shiromaru Haruo , Kobayashi Nobuo 
Published: May 2015

AbstractA highly charged ion facility built around a 14.25 GHz electron cyclotron resonance ion source has been constructed for the experimental investigation of low energy atomic collisions in Tokyo Metropolitan University. Four kinds of different experiments, namely differential scattering of electrons from ions, polarization spectroscopy for charge transfer reactions, Coulomb‐explosion‐imaging of molecular ions, and secondary ion measurements from solid surfaces, are taking place in parallel in this facility. General features of the facility and some recent results are described in this paper.
Atomic Structure Studies Using Tokamak Plasmas
Authors: Martinson Indrek , Jupén Christer 
Published: May 2015

AbstractAtomic processes play an important role in thermonuclear fusion research. In magnetically confined fusion plasmas atomic processes influence the energy balance of the plasma and the impurity transport. It has been known for more than 30 years that line radiation from plasma impurities will lead to energy losses and plasma cooling. However, the impurities are useful in plasma diagnostics. These facts have motivated intense spectroscopic work, using a variety of methods, in order to produce the atomic data needed by the fusion community. The spectroscopy of fusion plasmas has also yielded a wealth of new data for atoms and ions. A fusion plasma is an excellent light source ‐ with some unique properties ‐ for the spectroscopy of highly charged ions. Some examples will be discussed in this paper.
Giant Resonance in 4d Photo‐Ionization and ‐Excitation of High Z Atoms and Ions; Systematic Study of Dynamic Electron‐Correlation
Authors: Watanabe Tsutomu , Tong Xiao‐Min , Sato Masashi , Ohtani Shunsuke 
Published: May 2015

AbstractFor the study of so‐called 4d giant resonance of an Xe atom and its iso‐electronic sequence, the linear response method with the density functional theory is applied. Particular attention is made for the 4d photoexcitation process of Xe together with the continuum spectrum and the excitation peaks in the experiment are identified for the first time. Systematic study for iso‐electronic sequence of Xe‐like ions and atoms, i.e., I−, Xe, Cs+, Ba++ and La3+ are reported in order to see the role of the dynamic electron correlation to 4d‐photoexcitation/ionization processes.
Comparison of Excitation Processes by Proton and Antiproton Impacts on Hydrogen Atoms; Direct Solution of Time Dependent Schrödinger Equation
Authors: Watanabe Tsutomu , Tong Xiao‐Min , Kato Daiji , Ohtam Shunsuke 
Published: May 2015

AbstractMaking use of the direct solution for Schrödinger equation, the impact excitation of hydrogen atoms by proton and anti‐proton is studied. For the trajectory of projectile particles, we apply the straight line as well as curved trajectory. In order to save the number of glid, we employ the split‐operator method and pseudospectral (non‐uniform mesh) in energy representation. The calculations are compared with previous works of the traditional closed coupling impact parameter method and that of direct solution method. Comparison between the results of proton and anti‐proton impacts are physically discussed.
Photoionization Profiles of Helium Autoionizing States in External DC Electric Fields
Authors: Ho Yew Kam , Fang Te‐Kuei 
Published: May 2015

AbstractElectric‐field effects on the doubly excited resonant structures in He ground state photoionization are investigated theoretically using the complex‐rotation method with a B‐spline‐based configuration interaction (BSCI) basis. The variations of the structure profiles for the ML = 0 components of He (2,2a), (2,3 a), and (2,4a) 1P° and 1De resonance pairs for selected DC electric field strengths are examined. The changes of the resonant energies, widths, Fano q‐parameters, and back ground cross sections, are also presented.
A Model Study of High Harmonic Generation from Ions
Authors: Choi Jung‐Seock , Nam Baek Il , Kim Young Soon , Baik Moon‐Gu 
Published: May 2015

AbstractWe have studied the influences of atomic parameters and laser parameters with various atomic potentials and laser intensities on high harmonic generation (HHG) by solving the time‐dependent 1‐D Schrödinger equation with a soft‐core model potential. For these purposes we examine harmonic spectra for the cases of deeply bound initial states of ions in the hydrogen isoelectronic sequence. The harmonic signals for the lower order harmonics rapidly decrease so that the harmonic spectrum reveals a ‘well’ structure in the region of lower order harmonics, which is not common in the ordinary high harmonic spectrum. In order to explain the origin of this feature we also calculate HHG spectra for the cases where the excited states are initially populated. These studies naturally require considerations of quantum effects that are normally neglected, by which we under stand the limit of the semi‐classical theory of HHG.
A Proposal for Guiding and Trapping of Cold Atoms in the AC Field of Current‐Carrying Wires
Authors: Xu Lifang , Yin Jianping , Wang Yuzhu 
Published: May 2015

AbstractWe propose a novel ac electro‐magnetic guiding and trapping of cold neutral atoms, which is based on the interaction of a magnetic dipole moment of guided and trapped atom with both an ac quadrupole magnetic field in the trans verse direction and a dc‐bias magnetic field along the guiding axis. The time‐averaged magnetic potential and force for the atoms are calculated. And the results show that the potential is high enough to collect and guide nearly all of the cold atoms from a standard magneto‐optical trap with a temperature of ∼ 120 μK.
Study of Photodissociation Dynamics Using Sub‐Doppler Fluorescence Imaging Method: Photodissociation of ICN at 308 nm
Authors: Chang Jia‐Lin , Chen Kuo‐Mei , Lin Wei‐Yu , Chen Yit‐Tsong 
Published: May 2015

AbstractThe sub‐Doppler fluorescence imaging method has been developed to determine velocity distribution, angular distribution, and vector correlation of state‐selected photofragments. Using this new method, photodissociation dynamics can be studied directly in the center‐of‐mass frame, even with an uncollimated molecular beam. We have performed the experiment of photodissociation of ICN at 308 nm to demonstrate that recoil velocities of photofragments can be obtained with out collimating the parent beam. The forward‐ and backward‐scattered CN(X 2Σ+) photofragments are imaged simultaneously for the first time. The recoil velocities of the CN photofragments are measured and the bond dissociation energy D00(I–CN) is determined to be 26960 ± 120 cm‐1, in agreement with the literature values reported recently.
Sum Frequency Vibrational Spectroscopy of the Liquid‐Air Interface of Aqueous Solutions of Ethanol in the OH Region
Authors: Ju Shan Shan , Wu Tzong‐Daw , Yeh Yuh‐Lin , Wei Tai‐Huei , Huang Jung‐Yaw , Lin Sheng Hsien 
Published: May 2015

AbstractThe surface vibrational spectroscopy of ethanol (C2H5OH, ethyl alcohol): water binary mixture, or the aqueous solution of ethanol, is investigated via sum frequency generation (SFG) in the OH region (3000 to 3900 cm−1). The bulk molar ratio of the ethanol is varied from x = 0.0024 to 0.20. Our concentration dependence results support the statement that the surface density of water molecules with a free dangling OH bond is about 25% in the air/water interface. It also indicates that the ethyl group of the surface ethanol molecules sticks out above the nominal surface, while the hydroxyl group alone is immersed in the mixture solution. And the surface layer is a mixed monolayer. We have demonstrated here that a LiNbO3 crystal containing ‐OH can be sufficient for the SFG spectroscopy measurement in the ‐OH region regardless of its absorption dip.
Electronegativity Scaled as a Average Attracting Energy of Valence‐Shell Electrons in a Ground‐State Free Atom
Authors: Xia Zhining , Shen Qiting , Cao Chenzhong , Huang Ying , Li Shengshi Zhiliang 
Published: May 2015

AbstractThe total capability of an atom attracting valence electrons can be measured by the sum of ionization energies of valence electron in a ground‐state free atom plus its electron affinity called Total Attracting Energy, TAE = ΣniEi + EA, where, Ei is the ionization energy of the ith valence‐shell electron in a ground‐state free atom, ni is the number of valence‐shell electron bearing energy Ei, and EA is the electron affinity. And the electronegativity χCL is proportional to the average of TAE, AAE = TAEav, divided by Σni, the number of atomic valence‐shell electrons. χCL = 0.1813 TAEav = 0.1813 AAE = 0.1813 TAE/Σni, = 0.1813 (ΣniEI + EA)/Σni. Further, the atomic valence orbital electronegativity can be also obtained from the TAE value of an atom. Some discussions were made on several special aspects such as scale of rare gases, comparisons with Pauling's and Allen's scales, etc.