bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Facile One‐Pot Synthesis of 4‐Acyl and 4‐(1‐Hydroxyethyl)Sydnones
Authors: Tien Hsien‐Ju , Fang Gwo‐Ming , Lin Shaw‐Tao , Tien Ling‐Ling 
Published: June 2015

AbstractA series of 4‐formyl‐, 4‐acetyl‐ and 4‐(l'‐hydroxyethyl)sydnones have been prepared in good yields by reaction of sydnone with butyllithium or a Grignard reagent and N,N‐dimethylformamide, N,N‐dimethylacetamide and acetylaldehyde, respectively.
The Exact Icosahedral Symmetry Relations for Atomic Overlaps, Molecular Orbitals and Vibrational Species of C60 Buckyballs
Authors: Wang Bo‐Cheng , Chiu Ying‐Nan 
Published: June 2015

AbstractA computer adapted vector method and Euler angle transformation procedures are used to generate the relationship between the atomic orbitals of icosahedral C60 Buckminsterfullerene cluster and to produce symmetry adapted molecular orbitals and vibrational species. The atomic overlaps based on the orientational relationship of the orbitals are used to compute the approximate molecular orbital energies and normalization constants. One of the vibrations of Au, symmetry is used to interpret the isomeric (dyotropic) rearrangement that breaks and forms two bonds to change two pentagons to two hexagons and vice versa.
Natural Bond Orbital Study on the Nature of Binding in the H2 Molecule
Authors: Chang Tse‐Chiang , Hwang Tsung‐Sung 
Published: June 2015

AbstractWe use the natural bond orbital (NBO) method to decompose a MO wavefunction into the intuitive valence bond (VB) structures. At least two natural orbital type MO are required to describe the essential binding of the H2 molecule at all inter nuclear distances. At first the MO wavefunction is transformed into an unrestricted Hartree‐Fock wave‐function consisted of non‐orthogonal localized orbitals u' and v', and then the NBO method is used to decompose u' and v' into the physical meaningful orthogonal localized orbitals. Our results show that the orbitals u' and v' are decomposed into an atomic and an overlap parts. The latter part gives rise to the conventional ionic structure in the VB picture.
Substitution Reactions of Sulchemfonylated Sulfolenes with the Carbanion of Dimethyl Malonate
Authors: Chou Ta‐Shue , Yang Teng‐Kuci , Ko Chung‐Wen 
Published: June 2015

AbstractThe reactions of 4‐alkyl‐4‐(phenylsulfonyl)‐2‐sulfolenes with excess carbanion of dimethyl malonate in refluxing THF have been studied. The substitution reaction takes place at the 3‐position via an addition‐elimination process so that 3,4‐disubstituted 2‐sulfolenes are obtained. These products are isomerized to the corresponding3‐sulfolenes under basic conditions.
Vitamin E: Or Why We Don't Go Rancid
Authors: Ingold Keith U. , Burton Graham W. 
Published: June 2015

AbstractThe authors' chemical studies on vitamin E are summarized. These studies provide very strong support for the view that vitamin E owes its biological activity solely to the fact that it acts as a general purpose, lipid‐soluble, peroxyl‐radical‐trapping antioxidant.
Clerodane‐Type Diterpenoids from the Taiwanese Liverwort Schistochila Acuminata
Authors: Chen Jing‐An , Huang Chyuan‐De , Wu Chia‐Li 
Published: June 2015

AbstractThree cis‐clerodane‐type acids 3‐5 and one methyl ester 9 were identified from the liverwort Schistochila acuminata. The two new acids 3 and 5 were 12E and 12Z geometric isomers and the methyl ester 9 was first reported from nature.
Syntheses and Reactions of Rhenium Carbamoyl Complexes of the Type (CO)4Re(NH2R)(CONHR) (R = Ethyl, Allyl or Isopropyl)
Authors: Liao Wen‐Jui , Wang Yen‐Ju , Chen Jhy‐Der , Lin Ying‐Chih , Liu Ling‐Kang 
Published: June 2015

AbstractCarbamoyl complexes, (CO)4Re(NH2R)(CONHR)(R = ethyl, 1; R = allyl, 2; R = isopropyl, 3) were prepared by reactions of (CO)5ReBr (or (CO)5ReCH2SiMe3) with appropriate amines. Complexes 1, 2 and 3 reacted with CH3CH2COCl to give Re(CO)5(NH2R)+Cl− (R = ethyl, 4; R = allyl, 5; R ‐ isopropyl, 6). Complex 5 undergoes nucleophilic attack by KOMe to give the alkoxycarbonyl complexes (CO)4Re(NH2‐Allyl)(COOMe), 7. Complexes 4, 5, 6 and 7 were transformed to the corresponding carbamoyl complexes by reacting with appropriate amines. The reactions between the carbamoyl complexes and R″OH/CHCl3 in air at room temperature gave the proposed products [(CO)4Re(NH2R)]2O (R = allyl, 8; R = isopropyl, 9), respectively. Complex 8 can also be prepared by heating 7 in CDCl3 at 63–68°C for several days.The structure of 1 was confirmed by a X‐ray crystallographic study. Crystallographic data: space group P21/c, a = 8.193 (3) Å, b = 19.273 (3) Å, c = 9.348 (8) Å, β = 110.37 (4)°, V = 1383.68 Å3, Z = 4; R(F) = 0.027, Rw(F) = 0.030, based on 1888 reflections with I > 2.5σ(I). The other complexes were characterized by 1H NMR, 13CNMR, IR and mass spectra.
Dialkylative Cyclization Reactions of 3‐(Phenylthio)‐3‐Sulfolenes
Authors: Chou Shang‐Shiag P. , Sung Chin‐Chung , Sun Der‐Jen 
Published: June 2015

Abstract3‐(Phenylthio)‐3‐sulfolene (4) underwent bridged dialkylative cyclization with 2‐methylene‐1,3‐diiodopropane to give the bridged bicyclic 3‐sulfolene 23, and spirodialkylation with 1,4‐diiodobutane and 1,5‐diiodopentane to give the spiro bicyclic 3‐sulfolenes 15 as the major product. The reaction of 4 with 1,3‐diiodopropane led to the fused bicyclic 2‐sulfolene 12. 3‐(Phenylthio)‐3‐sulfolenes bearing an ω‐iodoalkyl group at the C‐2 position gave the fused bicyclic 2‐sulfolenes 28 and/or the spiro bicyclic 3‐sulfolene 29 depending on the chain length.
Crystal Structure of frans‐Dichloro(c‐Meso‐3,5,7,7,10,12,14,14‐Octamethyl‐1,4,8,11 ‐Tetraaza Cyclotetradeca‐4,11‐Diene)Cobalt(lll) Perchlorate
Authors: Lu Tian‐Huey , Chen Bor‐Hann , Chung Chung‐Sun 
Published: June 2015

AbstractThe crystal structure of the title compound has been solved by X‐ray diffraction. [CO(Cl)2(N4C18H36)]‐(ClO4), Mr = 537.79, triclinic, P1, a = 6.974(4), b = 8.530(1), c = 11.061(2) Å, α = 98.47(1), β = 106.56(3), γ = 93.02(3)°, V = 620.8(4) Å3, Z = 1, Dx = 1.439 Mg m−3, λ(MoKα) = 0.7093 Å, μ = 0.96 mm−1, F(000) = 291.93, T = 297(3) K, R = 0.072, Rw = 0.085 for 2121 observed reflections. The Co(III) is six‐coordinate with the four N atoms of the macrocyclic ligand equatorial and two Cl ions axial, thereby resulting in a tetragonally distorted octahedral geometry. Aside from the perchlorate group, there exists a non‐crystallographic inversion center at the Co(III) ion for the macrocyclic ligand and the two Cl ions which are bonded to the Co(III) ion.
Studies on the Formosan Soft Corals I‐Cytotoxic Cembrane Diterpenes from Sarcophyton Trocheliophorum
Authors: Wu Yang‐Chang , Hsieh Pei‐Wen , Duh Chang‐Yih , Wang Shang‐Kwei , Soong Keryea , Fang Lee‐Shing 
Published: June 2015

AbstractTwo cytotoxic cembranoid diterpenes, (+)‐isosarcophytoxide (1) and ( + )‐isosarcophine (2), were isolated from the soft coral Sarcophyton trocheliophorum by cytotoxicity‐guided fractionation. These two compounds demonstrated potent cytotoxicity against P‐388 and HL‐60 cells.
Theoretical Calculations of Dipole Moments, Polarizabilities, and Hyperpolarizabilities of HF, OCS, O3, CH3F, and CH3Cl by Local Density Approximation
Authors: Chong Delano P. 
Published: June 2015

AbstractThe dipole moments, polarizabilities, and hyperpolarizabilities of five molecules (HF, OCS, O3, CH3F, and CH3Cl) have been computed at their experimental equilibrium geometries using the deMon density functional program. For molecules of such sizes, we augmented the basis set of valence double‐zeta plus polarization functions with field‐induced polarization functions. Contamination of least‐squares fitted parameters by higher‐order hyperpolarizabilities have been greatly reduced by fitting the field‐dependent dipole moments to eighth order polynomials using as many as 37 points per molecule. The results compare well with experiment.
Magnetic and Spectral Properties of Heterotrinuclear Acetates [Ru2Co(μ3‐O)(μ‐CH3CO2)6(Py)3]n+ (n = 0 or 1)
Authors: Dong Teng‐Yuan , Lee Hui‐Shien , Lee Ting‐Yu , Hsieh Chia‐Feng 
Published: June 2015

AbstractThe preparation and physical properties of the new heterotrinuclear acetates, [Ru2CO(μ3‐O)(μ‐CH3CO2)6(Py)3] (Ru2Co(II)) and [Ru2Co(μ3‐O)(μ‐CH3CO2)6(Py)3)l3 (Ru2Co(III), Py = pyridine), are reported. Three reversible one‐electron‐redox waves are observed at 1.19, 0.40, and −1.24 V vs Ag/Ag+ electrode for Ru2Co(lI) in CH2Cl2. The complexes of Ru2Co(II) and Ru2Co(III) show an intense visible absorption at 570 (ϵ 5950 M−1 cm−1) and 551 nm (ϵ 7240 M−1 cm−1), respectively. The magnetic susceptibilities of both complexes were also measured from 4.2 to 300 K. The resulting least‐squares fit parameters for Ru2Co(II) areJRuCo = −9 cm−1, JRuRu = −22 cm−1, gCo, = gRu= 2.19.
Spectroscopic Studies of 1‐Aryl‐2,2‐Dichlorocyclopropanes
Authors: Lin Shaw‐Tao , Yao Yi‐Fen 
Published: June 2015

AbstractSeventeen 1‐aryl‐2,2‐dichlorocyclopropanes were examined by using IR, 13C NMR, and mass spectrometry. The data obtained from IR and 13C NMR spectra indicate that the bond strength of carbon‐chlorine on the cyclopropane ring and the electron density of that carbon depend on the substituent. The mass fragmentation patterns of compounds in this series resemble those of the dibromo analogues. The fragmentation mechanism is proposed to involve the formation of indenium ion through an electrocyclization.
Rate of Reaction of Electron Transfer over a Long Range and Mediated by a Solvent
Authors: Chen Jin‐Ming , Mou Chung‐Yuan , Lin S. H. 
Published: June 2015

AbstractWe present a simple quantum mechanical model for solvent bridge‐mediated long‐range nonadiabatic electron‐transfer reaction rate. A perturbation theory using a one‐electron model is employed to treat the electronic transition element that includes donor, acceptor and bridge unit wave functions. Reaction‐coordinate activation is treated by high‐temperature approximation. The pre‐exponential factor in the rate coefficient becomes dependent on the distance between donor and acceptor; the decay length depends strongly on the driving force and is effective at a large range if the level of energy of the donor is nearly that of the bridge. This condition is satisfied for a process of electron transfer with excited donor molecules or in the highly exothermic regime.According to a simple model calculation, the non‐existence of an “inverted” regime in highly exothermic reaction is favored for solvent media with large relative permittivity and low‐lying HOMO (highest occupied molecular orbital) or LUMO (lowest unoccupied molecular orbital). In the normal regime in which the driving force (ΔG°) is positive or nearly zero this effect at large‐range is negligible, and transfer of the electron occurs mostly at the distance of contact.
Mössbauer and Magnetic Studies on the Spin‐State Transitions of Iron Complexes
Authors: Wei Ho‐Hsiang 
Published: June 2015

AbstractMössbauer and magnetic studies on the spin‐state transitions in various complexes of iron(II) and iron(III) ions have received considerable attention. The present account deals with some examples of the effects of intraligand substitution and sample size on the spin‐state transitions of 5T2 ↔ 1A1 for iron(II) and 6A1 ↔ 2T2 for Iron(III)‐complexes. A new instance of 3T1 ↔ 5T2 spin‐crossover Fe(II)‐complex is reported.
Syntheses and Reactions of Sulfur‐ and Phosphorus‐ Ylide Metal Complexes Promoted with Phase‐Transfer Catalysts and Hydrolysis of Bis(diphenylphosphino)methane
Authors: Lin Ivan J. B. , Shen H. I. 
Published: June 2015

AbstractPhase‐transfer catalysts (PTC) promoted synthesis of sulfur‐ and phosphorus‐ylide complexes of Pd(II), Pt(II) and Au(I). Because in most cases, the presence of PTC enhances the rate of formation of ylide complexes, this method is advantageous over the conventional one under anhydrous conditions. Reactions of these ylide complexes are described. Basic hydrolysis of dppm (dppm = Ph2PCH2PPh2) in Pt‐dppm complexes was also promoted by PTC and produces PPh2Me and PPh2O− (or PPh2OH) ligands. Other products from various Pt‐dppm reactions are discussed.
Chemistry of α‐Ketoacyl Metal Complexes
Authors: Chen Jwu‐Ting 
Published: June 2015

AbstractThe α‐ketoacyl complexes constitute a new family of organometallic compounds. The α‐ketoacyl ligands have a strong influence and generally follow a decreasing order of acyl > α‐ketoacyl > alkyl or aryl. The oxalyl conformation exhibits planar s‐cis, perpendicular and planar s‐trans structures. In comparison with the standard C(sp2)‐C(sp2) bond, the oxalyl C‐C bonds of the α‐ketoacyl ligands are relatively long, indicating that the electronic derealization between the oxalyl carbonyls are of the least importance. The weak C‐C bond between the α‐ketoacyl carbonyls affords a driving force of the decarbonylative reactivity of such ligands; it is also responsible for the difficulty of formation of the α‐ketoacyl complex via insertion of CO into the metal‐acyl bond. However, α‐ketoacyl complexes can be kinetically stable. Kinetic studies of decarbonylation of the α‐ketoacyl complexes provided a profound understanding of the mechanism of novel catalytic reactions of double carbonylation. The α‐ketoacyl complexes show promise to explore rare acyl migration and the reductive coupling of C(sp2)‐C(sp2) bonds in a fundamental way.
Correlation Analyses of Solvolytic Rate Data with Single‐ and Dual‐Parameter Hammett Equations
Authors: Liu Kwang‐Ting 
Published: June 2015

AbstractThe results of detailed examinations on the comparison of Hammett‐type correlation analysis of solvolytic rate constants with single‐ and dual‐parameter equations are summarized. From the difference of ρ values, the variation of γ values with numbers of data points, the solvent intervention in the standard reactions for defining σ+ constants, the influence of o‐methyl group on the reactivity of the reference substrate (tert‐cumyl derivatives), and the behavior of the α‐aryl group in highly congested systems, it could be concluded that both the Hammett‐Brown and the Yukawa‐Tsuno treatments of solvolytic rate constants are only approximations. Although in some cases the use of the dual‐parameter Yukawa‐Tsuno equation (Eq. 4) could give a better correlation and a more proper explanation than the use of the single‐parameter Hammett‐Brown equation (Eq. 2), in other cases the excellent correlation observed from the former might be merely a computational artefact. Therefore, the result obtained from the Yukawa‐Tsuno equation should be interpreted with caution.
Substitution Reactions of 3‐Sulfolenyl Carbanions
Authors: Chou Ta‐Shue , Chou Shang‐Shing P. 
Published: June 2015

Abstract3‐Sulfolenes are easily converted to the corresponding 1,3‐dienes by cheletropic removal of SO2. In addition, the generation of 3‐sulfolenyl anions are achieved under several reaction conditions. Therefore, 3‐sulfolenes serve as butadienyl anion equivalents and this stragegy has been applied to the preparations of substituted dienes and the total synthesis of natural products.
Chemical Constituents of Some Endemic Conifers in Taiwan
Authors: Fang Jim‐Min , Cheng Yu‐Shia 
Published: June 2015

AbstractChemical constituents of conifers of families of Cupressaceae, Pinaceae and Taxodiaceae, of which endemic species such as Chamaecyparis taiwanensis, Chamaecyparis formosensis, Calocedrus formosana, Pinus armandii, Tsuga chinensis and Taiwania cryptomerioides are emphasized. The chemical constituents mainly include terpenes, lignans and flavones. Methods and significance of this research are discussed. Extraction, crystallization and chromatography are general methods for separation of plant constituents. Chemical and spectral methods including IR, MS and NMR are frequently used for structural determination along with X‐ray crystallography and circular dichroic spectroscopy to establish absolute configuration in appropriate cases. Finding hinokitiol from Taiwan cypress has initiated the emerging study of troponoid chemistry and nonbenzenoid aromatic compounds. A norsesquiterpene chamaecynone and a mixture of sesquiterpenes T‐cadinol and T‐muurolol exhibit respectively termiticide and antifidant activities. The flavonoid and stilbene constituents are analyzed to support the chemotaxonomy of armand pine and Taiwan white pine. A study of the constituents of armand pine indicates that 30‐nor‐3β‐methoxyserrat‐14‐en‐21‐one is biogenetically derived from 3β‐methoxyserrat‐14‐en‐21‐one by an oxidative degradation via intermediacy of the 30‐alcohol and the 30‐aldehyde.
Peptide Synthesis in Organic Solvents Catalyzed by an Industrial Alkaline Protease “Alcalase”
Authors: Chen Shui‐Tein , Wang Kung‐Tsung 
Published: June 2015

AbstractAn industrial alkaline protease “Alcalase” is stable (half life > 5 days in ethanol or in t‐butanol) and active in alcoholic solvents (except methanol), and usable as a catalyst for kinetically controlled peptide bond formation in these solvents. We give an overview of our use of alcalase as catalyst in peptide synthesis; it includes 1) the stability of alcalase in various organic solvents; 2) the resolution of N‐protected amino acids at large concentration of organic solvent; 3) the saponification of Fmoc‐peptide esters in high concentration of organic solvent; 4) kinetically controlled peptide bond formation in alcoholic solvent, and 5) enzymatic synthesis of a Cathepsin inhibitor, peptidyl Q‐acyl hydroxamates.
The effects of a low‐salt diet on the efficacy of different antihypertensive drug regimens
Authors: Wang Jing , Qiu Bo , Du Jian‐Lin , Deng Song‐Bai , Liu Ya‐Jie , She Qiang 
Published: June 2015

AbstractThe objective of this study was to compare the antihypertensive effects of 3 types of antihypertensive drug regimens between different salt intake levels. The 180 patients with mild to moderate primary hypertension participating in this randomized, controlled clinical trial were randomly allocated to a low‐salt diet (LSD) group or a non‐low‐salt diet (NLSD) group. Each group included 3 subgroups: a losartan 100 mg subgroup, a losartan 50 mg/hydrochlorothiazide (HCTZ) 12.5 mg subgroup, and an irbesartan 150 mg/HCTZ 12.5 mg subgroup. The LSD group received a diet in which the sodium content was strictly controlled (2.3 g/day). After 2 months, the office blood pressure (BP), the 24‐hour mean BP, and the morning BP were significantly reduced (P ≤ .01) in each group. No significant differences were observed between the 3 LSD subgroups (P > .05). In the NLSD group, the losartan 50 mg/HCTZ 12.5 mg subgroup, and the irbesartan 150 mg/HCTZ 12.5 mg subgroup exhibited identical antihypertensive efficacy (P > .05), and these groups were significantly different from the losartan 100 mg subgroup(P ≤ .05). The BP of the patients who received the LSD was further decreased compared with those who received the NLSD (P ≤ .05). Therefore, we concluded that this LSD exerts synergistic BP‐reducing effects.
On the Roots of σ‐Polynomials
Authors: Brown Jason , Erey Aysel 
Published: June 2015

AbstractGiven a graphGof ordern, the σ‐polynomialofGis the generating functionwhereis the number of partitions of the vertex set ofGintoinonempty independent sets. Such polynomials arise in a natural way from chromatic polynomials. Brenti (Trans Am Math Soc 332 (1992), 729–756) proved that σ‐polynomials of graphs with chromatic number at leasthad all real roots, and conjectured the same held for chromatic number. We affirm this conjecture.
Improving and sustaining a reduction in iatrogenic pneumothorax through a multifaceted quality‐improvement approach
Authors: Shieh Lisa , Go Minjoung , Gessner Daniel , Chen Jonathan H. , Hopkins Joseph , Maggio Paul 
Published: June 2015

BACKGROUNDThe Agency for Healthcare Research and Quality has adopted iatrogenic pneumothorax (IAP) as a Patient Safety Indicator. In 2006, in response to a low performance ranking for IAP rate from the University Healthsystem Consortium (UHC), the authors established a multidisciplinary team to reduce our institution's IAP rate. Root‐cause analysis found that subclavian insertion of central venous catheterization (CVC) was the most common procedure associated with IAPOBJECTIVEOur short‐term goal was a 50% reduction of both CVC‐associated and all‐cause IAP rates within 18 months, with long‐term goals of sustained reduction.DESIGNObservational study.SETTINGAcademic tertiary care hospital.PATIENTSConsecutive inpatients from 2006 to 2014.INTERVENTIONOur multifaceted intervention included: (1) clinical and documentation standards based on evidence, (2) cognitive aids, (3) simulation training, (4) purchase and deployment of ultrasound equipment, and (5) feedback to clinical services.MEASUREMENTS: CVC‐associated IAP, all‐cause IAP rate.RESULTSWe achieved both a short‐term (years 2006 to 2008) and long‐term (years 2006 to 2008–2014) reduction in our CVC‐associated and all‐cause IAP rates. Our short‐term reduction in our CVC‐associated IAP was 53% (P = 0.088), and our long‐term reduction was 85% (P < 0.0001). Our short‐term reduction in the all‐cause IAP rate was 26% (P < 0.0001), and our long‐term reduction was 61% (P < 0.0001).CONCLUSIONSA multidisciplinary team, focused on evidence, patient safety, and standardization, can use a set of multifaceted interventions to sustainably improve patient outcomes for several years after implementation. Our hospital was in the highest performance UHC quartile for all‐cause IAP in 2012 to 2014. Journal of Hospital Medicine 2015;10:599–607. © 2015 Society of Hospital Medicine
Characterization of light extraction efficiency for WOLEDS with light‐out‐coupling layer
Authors: Harada Motoko , Wakana Hironori , Nobuki Shunichiro , Sakuma Hirotaka , Kawasaki Masahiro , Aratani Sukekazu 
Published: June 2015

AbstractWe studied the light extraction efficiencies of white organic light‐emitting diodes with a light‐out‐coupling layer by simulations and experiments. The light extraction efficiencies estimated by the simulation were confirmed to agree well with those measured by the experiments. Moreover, we successfully obtained the high light extraction efficiency (ηOC) of 69%.
Biobased Aliphatic Polyesters with DOPO Substituents for Enhanced Flame Retardancy
Authors: Pospiech Doris , Korwitz Andreas , Komber Hartmut , Jehnichen Dieter , Häußler Liane , Scheibner Holger , Liebmann Michael , Jähnichen Klaus , Voit Brigitte 
Published: June 2015

Linear aliphatic copolyesters consisting of the biobased diols ethylene glycol, 1,3‐propane diol, and 1,4‐butane diol, the biobased dicarboxylic acids succinic acid, adipic acid, and sebacic acid, and a 9,10‐dihydro‐9‐oxa‐10‐phospha‐phenanthren‐10‐oxide (DOPO)‐containing diol or dicarboxylic acid are presented. Structural characteristics of the new copolyesters are studied by 1H and 13C NMR spectroscopy. The influence of chemical composition on the property profile is examined evaluating glass transition temperature Tg, melting behavior, thermal degradation and combustion, mechanical and burning behavior. Incorporation of DOPO monomers suppresses crystallization and yields materials with reduced toughness except in case of sebacates. Tg rises with the content of DOPO monomer. Correlations between the number of methylene groups in the repeating unit and the thermogravimetric analysis degradation maximum, as well as the heat release capacity from pyrolysis combustion flow calorimeter reflect the systematic influence of chemical structure. Copolycondensation with DOPO monomers enhances the limiting oxygen index providing materials with improved overall value.
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