bluuebunny/crossref_metadata_2025_split huggingface dataset:
Snx.Ti1‐xO2 solid solution catalysts for nitrogen oxide selective catalytic reduction by propene in presence of oxygen
Authors: Wei Ji‐Ying , Ma Jun , Zhu Yue‐Xiang , Cai Xiao‐Hai , Xie You‐Chang 
Published: September 2010

AbstractA series of SnO2‐TiO2 binary oxide catalysts prepared by co‐current precipitation method was found to be a novel and good system for the selective catalytic reduction of NO by propene in the presence of oxygen with high activity and good selectivity to N2. The NO conversion to N2 over SnO2‐TiO2 oxide catalysts varied with SnO2 content and attainted a maximum at 65% over the catalyst with SnO2 content at 40wt% for a feed with 1186 ppm NO, 948 ppm propene and 2.23% O2, in He and a space velocity of 15000 h−1 at 350°C. The SnO2TiO2 catalysts could sustain moderate activity in the presence of 10% steam. Because of the identical valence and the similar radius of Sn4+ and Ti4+, SnO2‐TiO2 binary oxides can form solid solution in three different phases as proved by XRD, electron diffraction and TPR. Sn4+ is the main active species in the SnO2‐TiO2 catalysts, and it is enriched on the solid solution surface as tested by XPS analysis. H2‐TPR, NH3‐TPD and BET tests show that SnO2‐TiO2 solid solution can dilute SnO2 and suppress the activity of propene complete oxidation over SnO2. This may be beneficial to the reactivity enhancement of NO conversion.
Study on spline wavelet self‐convolution in filtering and resolving overlapped voltammetric signals simultaneously
Authors: Zhang Yong‐Qing , Mo Jin‐Yuan , Cai Pei‐Xiang 
Published: September 2010

AbstractThe normal distribution function is used as resolving factor and spline wavelet self‐convolution is used to resolve the overlapped peaks containing noise. The resolution of several kinds of overlapped peaks (SNR from 5 to 50) simulated by computer has been discussed in details. It is known that the overlapped peaks with noise can be separated (SNR > 50) directly and the noise is removed at the same time in time domain. Base‐line separation can be achieved. The relative errors of peak area and position are less than 5.0%. The satisfactory results are also obtained in resolving voltammetric overlapped signals by this method.
Flavonoids from the red alga Acanthophora spicifera
Authors: Zeng Long‐Mei , Wang Chao‐Jie , Su Jing‐Yu , Li Du , Owen Noel L. , Lu Yang , Lu Nan , Zheng Qi‐Tai 
Published: September 2010

AbstractTwo new flavonoids, acanthophorin A (1) and acanthophorin B (2), along with three known compounds tiliroside (3), (‐)‐catechin (4) and quercetin (5) were isolated from the red alga Acanthophora spicifera. The structures of 1 and 2 were determined to be kaempferol 3‐O‐α‐L‐fucopyranoside (1) and quercetin 3‐O‐α‐L‐fucopyranoside (2) by spectroscopic methods. Both 1 and 2 showed significant antioxidant activity.
Preparation of weak cation exchange packings based on monodisperse poly(chloromethylstyrene‐co‐divinylbenzene) particles and its chromatographic properties
Authors: Wei Yin‐Mao , Chen Qiang , Geng Xin‐Du 
Published: September 2010

AbstractMonodisperse poly (chloromethylstyrene‐co‐divinylbenzene) particles were firstly prepared by a two‐step swelling method. Based on this media, one kind of weak cation ion exchange packings was prepared. It was demonstrated that the prepared packings have comparative advantages for biopolymer separation with high column efficiency, low interstitial volume and low column backpressure, and have good resolution to proteins. The effects of salt concentration and pH of mobile phase on protein retentions were investigated. The properties of the weak cation ion exchange packings were evaluated by the unified retention model for mixed‐mode interaction mechanism in ion exchange and hydrophobic interaction chromatography.
A novel CC bond cleavage reaction of 2, 2′‐pyridil in solution
Authors: Ren Rui , Yang Pin , Jin Xiang‐Lin 
Published: September 2010

Abstract2,2′‐Pyridil reacted with CuCl2 to give C–‐C bond cleavage product (picolinate)2Cu, and its structure has been unambiguously confirmed by an X‐ray structural analysis.
A concise strategy for polymer‐supported regio‐oriented introduction of various building blocks onto glucopyranoside scaffold
Authors: Liao Yuna , Li Zheng‐Ming , Wong Henry N. C. 
Published: September 2010

AbstractA new strategy was devised to stereo‐specifically introduce various building blocks, mainly heterocycles such as pyrimidines and triazines onto a multi‐hydroxy molecule. A glucopyranoside was chosen as a target scaffold. Two polymer‐based protective reagents were jointly integrated in the implementation of the strategy. It was found that in the α‐D‐glucopyranoside, which has four free hydroxyl groups within the same molecule, its 4, 6‐di‐OH could be simultaneously protected by polystyryl boronic acid, which left the 2, 3‐di‐OH free for substitution. Due to the steric effects within the molecule, the 2‐OH is much more liabile to electrophilic substitution. Thus the first and the second building blocks could be introduced regioselectively onto the 2‐OH and the 3‐OH positions. After a facile deprotection, the 4, 6‐di‐OH were left free and by application of a second protecting reagent–‐polystyryltritylchloride onto 6‐OH, a third building block was introduced onto the 4‐OH position. After further deprotection, the fourth building block was later introduced onto the 6‐OH position. The new strategy was successfully applied in the combinatorial synthesis by application of the split‐mix technique. The respective eleven small libraries were obtained and confirmed by HPLC‐MS and NMR. Some preliminary results on chemical structure/herbicidal activity relationship were discussed.
Asymmetric reduction of aminoketones with borane and chiral oxazaborolidine catalyst
Authors: Zhang Ya‐Wen , Shen Zong‐Xuan , Qin Hong‐Bing , Li Yong‐Hua , Yu Kai‐Bei 
Published: September 2010

AbstractA group of α‐ and β‐N, N‐dialkyl amino ketones were reduced enantioselectively by 2 moles of borane‐tetrahydrofuran in the presence of 10 mol% of the in‐situ formed chiral oxazaborolidine, followed by diluted hydrochloric acid. The resulting amino alcohol‐borane complexes were treated with hydrogen chloride‐glycol‐methanol to give the optically active amino alcohol with the ee up to 99%.
Palladium‐catalyzed carbonylation of primary amines in supercritical carbon dioxide
Authors: Li Jin‐Heng , Jiang Huan‐Feng , Chen Ming‐Cai 
Published: September 2010

AbstractThe chemoselectivity of the palladium‐catalyzed carbonylation of amines was affected by the addition of MeOH in supercritical carbon dioxide. The results show different selectivity in supercritical carbon dioxide CO2(sc) from that in alcohol. Methyl carbamate and its derivatives were obtained in high yields in CO2(sc).
Sm°/Cat. I2 and SmI2 induced reductive coupling of nitriles with azides
Authors: Su Wei‐Ke , Li Yong‐Shu , Zhang Yong‐Min 
Published: September 2010

AbstractThe intermolecular reductive coupling of nitriles with azides induced by Sm°/Cat. I2 or SmI2 was studied. Aromatic and aliphatic amidines were prepared in moderate to good yields under neutral and mild conditions respectively.
Photoinduced hydrogen abstraction‐coupling reaction mechanism of Δ5‐steroids with substituted 1, 4‐benzoquinones via electron transfer pathways
Authors: Yang Cheng‐Gen , Jiang Zhi‐Qin , Zhu Dun‐Ru , Wu Shu‐Ping , Yang Li , Wu Long‐Min 
Published: September 2010

AbstractThe photochemical reaction between three A5‐steroids (1–3) and a series of substituted 1,4‐benzoquinones and their mechanistic study were reported. The reaction in nitrogen atmosphere led to the formation of three products including the steroid‐quinone coupling compound (A), 7‐hydroxy derivatives of Δ5‐steroids (B) and substituted 1, 4‐hydroquinone (C). Both chemical and spectrometric evidences such as UV‐Visible spectra, ESR, chemically induced dynamic nuclear polarization (CIDNP) and cyclic voltammetry (CV) verified that the title reaction underwent a predominant photoinduced electron transfer pathway via the triplet quinone.
A concise synthesis of antigenic factor 4 existing in Candida albicans
Authors: Zhu , Yu‐Liang , Chen Lang‐Qiu , Kong Fan‐Zuo 
Published: September 2010

AbstractA concise synthesis of α‐Man1 → 2‐α‐Man1 → 3‐(α‐Man1 → 6)‐α‐Man1 → 2‐α‐Man1 → 2‐α‐Man1 → 2‐Man, the antigenic factor 4 existing in Candida albicans, was achieved via TMSOTf promoted condensation of the corresponding acylated tetrasaccharide donor with the trisaccharide acceptor.
Synthesis, characterization and cd spectra studies of chiral calixsalen complexes
Authors: Zhang Yu‐Ling , Gao Feng , Ruan Wen‐Juan , Zhu Zhi‐Ang , Chen Yun‐Ti 
Published: September 2010

AbstractA chiral macrocyclic Schiff base ligand and its binuclear metal complexes of Fe, Co, Ni and Cu were synthesized by a modified method with 1,2‐diaminocyclobexane as the starting material, which is readily obtained. The characters of those complexes were studied by elemental analyses, MS, NMR, FT‐IR, UV‐Vis and CD (Circular Dichroism) spectra. Furthermore, the electronic absorption spectra and CD spectra properties of the chiral complexes were discussed.
Novel asymmetric total synthesis of (+)‐6‐epicastanospermine
Authors: Zhang Hong‐Xing , Xia Peng , Zhou Wei‐Shan 
Published: September 2010

AbstractAn asymmetric total synthesis of (+)‐6‐epicastanospermine was achieved in 13 steps and 19% overall yield from β‐hydroxy‐α‐furfurylamine derivative, which was prepared by Sharpless asymmetric aminohydroxylation of furyl acrylate.
Preparation of the Solid Electrolytes Li4+xAlxSi1‐xO4‐yAl2O3 by the Sol‐Gel Method and Study of Their Ionic Conductivity
Authors: Chen Ru‐Fen , Song Xiu‐Qin 
Published: September 2010

AbstractThe Li4+xAlxSi1‐xO4‐yAl2O3(x = 0 to 0.5, y =0 to 0.5) ion conductors were prepared by the Sol‐Gel method and examined in detail. The powder and sintered samples were characterized by TG‐DTA, XRD, SEM, and AC impedance techniques. The experimental results show that the conductivity and sinterability increase with the amount of excess Al2O3 in the silicate. The particle size of the powder samples is about 0.13 μm. The maximum conductivity at 18 °C. is 3.057 × 10−5 s/cm for Li4.4Al0.4Si0.6O4‐0.3 Al2O3.
Synthesis of Polyacrylaminothiourea Chelating Fiber and Properties of Concentration and Separation of Trace Noble Metal Ions from Samples
Authors: Wang Yan , Zhao Jian‐Guo , Gong Bo‐Lin , Sun Yan‐Pu 
Published: September 2010

AbstractA novel polyacrylaminothiourea chelating fiber was synthesized simply and rapidly from nitrilon (an acrylonitrile‐based synthetic fiber), which was applied to preconcentrate and separate of trace amount of Au(III), Pt(IV), Pd(IV) and Ir (IV) ions from solution of samples. The analyzed ions can be quantitatively concentrated by the fiber up to a flow rate of 20.0 mL/min at pH2, and can also be desorbed with 15 mL of 4 mol/L HCl + 3% thiourea from the fiber column with recoveries of 96.5%‐100%. The chelating fiber can be reused for ten times, the recoveries of these ions are still over 92%, and hundred to thousand times of excess of Fe(III), Al(III), Ca(II), Mg(II), Ni(II), Mn(II), Cu(II), Zn(II), and Cd (II) cause no interference on the determination of the analyzed ions by inductively‐coupled plasma atomic emission spectrometry (ICP‐AES). The static saturation adsorption capacities of the fiber for the analytes are in the range of 1.15‐2.80 mmol/g. The relative standard deviations for the determination of 20.0 ng/mL each of Au(III), Pt(IV), Pd(IV) and Ir (IV) are in the range of 0.7%‐3.0%. The recoveries for test from standard additions to real solution samples are between 96% and 100%. The concentration of each ion in powder sample detected by the method is in good agreement with the certified value.
Synthesis of Cyanobenzaldehydes (m‐, o‐, p‐) by Molecular Oxygen Oxidation Methods
Authors: Zhang Ling‐Yue , Yang Fan , Zhu Hua‐Ping , Tang Jie , He Ming‐Yuan 
Published: September 2010

AbstractCyanobenzaldehydes (m‐, o‐, p‐) were synthesized by oxidation of corresponding tolunitriles with molecular oxygen, catalyzed by cobalt acetate and sodium bromide.
Facile Preparation of Homoallyl β',γ'‐Unsaturated Amines via 1, 2‐Addition of α, β‐Unsaturated Imines with Allylsamarium Bromide
Authors: Chen Jue , Zhang Yong‐Min 
Published: September 2010

AbstractA series of homoallyl β',γ'‐unsaturated amines were synthesized via 1,2‐addition of α,β‐unsaturated imines with allylsamarium bromide in excellent yields under mild and neutral conditions.
Immobilization of Pd(n) Catalysts for Cyclopropanation in Ionic Liquid
Authors: Yang Fan , Zhang Yang‐Ming , Qiu Wen‐Wei , Tang Jie , He Ming‐Yuau 
Published: September 2010

AbstractCyclopropanation of styrene with ethyl diazoacetate catalyzed by Pd(II) in ionic liquid [omim][BF4] was investigated. Palladium catalysts can be effectively immobilized in ionic liquid. The catalysts PdCl2 and cyclopalladated complex 2 contained in ionic liquid could be recycled for 6 and 7 times, respectively, without losing the efficiency.
Perylene Nanoparticles Prepared by Reprecipitation Method
Authors: Ji Xue‐Hai , Fu Hong‐Bing , Xie Rui‐Min , Xiao De‐Bao , Yao Jian‐Nian 
Published: September 2010

AbstractPerylene nanoparticles with different sizes were prepared by reprecipitation method. It is found that the nanoparticles show size‐dependent optical property. Electron diffraction patterns indicate that all the nanoparticles of different sizes are in crystalline state. The rapid growth of the nanoparticles during the aging process could be slowed down effectively by the addition of cationic or anionic surfactants.
Electrocatalytic Oxidation of Dopamine by Ferrocene in Lipid Film Cast on a Glassy Carbon Electrode
Authors: Wang Jian‐Guo , Wu Zheng‐Yan , Tang Ji‐Lin , Teng Ren‐Rui , Wang Er‐Kang 
Published: September 2010

AbstractThe ferrocene‐lipid film electrode was successfully prepared by means of casting the solution of ferrocene and lipid in chloroform onto a glassy carbon (GC) electrode surface. Ferrocene saved in the biological membrane gave a couple of quasi‐reversible peaks of cyclic voltammogram. The electrode displays a preferential electrocatalytic oxidation of dopamine (DA). The effect of electrocatalytic oxidation of DA depends on the solution pH and the negative charge lipid is in favor of catalytic oxidation of DA. The characteristic was employed for separating the electrochemical responses of DA and ascorbic acid (AA). The electrode was assessed for the voltammetric differentiation of DA and AA. The measurement of DA can be achieved with differential pulse voltammetry in the presence of high concentration of AA. The catalytic peak current was proportional to the concentration of DA in the range of 1 × 10−4–3 × 10−3 mol/L.
Effects of Self‐coiling of Organic Molecules on Intramolecular Exciplex Formation and Fluorescence Quenching in DX‐H2O Solvent System
Authors: Chen Ying‐Qi , Li Zhan‐Ting , Wang Xiao‐Zhong , Jiang Xi‐Kui , Shi Ji‐Liang , Shi Min 
Published: September 2010

AbstractEffects of self‐coiling of organic molecules on intramolecular exciplex formation of compound I, in which the carbazole chromophore and terephthalic acid methylester acceptor group are linked by one (CH2)10 chain, and the decrease of the fluorescence intensities of compounds II, III, and IV, in which the carbazole chromophore and 3,5‐dinitrobenzoate are connected by one aliphatic chain of (CH2)10 (II), (CH2)12 (III), or (CH2)4 (IV), have been studied in the dioxane(DX)‐H2O binary system. The results show that self‐coiling of organic molecules in DX‐H2O facilitates intramolecular exciplex formation of I and induces the decrease of fluorescence intensities of II, because of the proximity effect brought about by self‐coiling of organic molecules under hydrophobic‐lipophilic interaction (HLI) between the excited carbazole chromophore and the acceptor. Since the similar effects are observed even when the concentrations of the probes are less than their CAgCs (critical aggregate concentrations) in the DX‐H2O mixture with the same ϕ values, formation of the intermolecular exciplex has been excluded. The effects are found to be strongly depended on ϕ values, indicating that they are mainly driven by HLI. The properties of the acceptors can also affect the intramolecular exciplex formation. With terephthalic add methylester moiety as the acceptor, the carbazole chromophore exhibits the fluorescence spectra of the exciplex, while with 3,5‐dinitrobenzoate moiety as the acceptor, only the fluorescence spectra of excited carbazolyl chromophore are observed.
Synthesis and Antibacterial Activities of 4‐Amino‐3‐(1‐aryl‐5‐methyl‐1,2,3‐triazol‐4‐yl) ‐5‐mercapto‐1, 2,4‐triazoles/2‐ Amino‐5‐(1‐aryl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐1,3,4‐thiadiazoles and Their Derivatives
Authors: Zhang Yan , Sun Xiao‐Wen , Hui Xin‐Ping , Zhang Zi‐Yi , Wang Qin , Zhang Qi 
Published: September 2010

AbstractTreatment of 4‐amino‐3‐(1‐aryl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐5‐mercapto‐1, 2,4‐triazoles/2‐amino‐5‐(1‐aryl‐5‐methyl‐1,2, 3‐triazol‐4‐yl)‐1,3,4‐thiadiazoles with benzaldehyde, acetone and ω‐bromoacetophenone was tested and compared. The title compounds Schiff bases, amides, imidazolo[2, 1‐b]‐1,3,4‐thiadiazoles and 7H‐s‐triazolo [3, 4‐b]‐1, 3, 4‐thiadiazines have been confirmed by elemental analyses, 1H NMR, IR and MS spectra. All the compounds have also been screened for their antibacterial activities against B. subtilis, S. aureus and E. coli.
Two‐dimensional Network Crown Ether Complex. Synthesis and Crystal Structure of 18‐Crown‐6 Complex: [K(18‐C‐6)]2[Cd‐(mnt)2]
Authors: Wang Da‐Qi , Yu Qing‐Jiang , Dou Jian‐Min 
Published: September 2010

AbstractThe novel complex [K(18‐C‐6)]2[Cd(nmt)2] [18‐C‐6=18‐crown‐6, mnt = 1, 2‐dicyanoethene‐1, 2‐dithiolate, C2S2‐(CN)]2−2] was synthesized and characterized by elemental analysis, IR spectrum and X‐ray diffraction analysis. The complex displays two‐dimensional network structure of [K(18‐C‐6)] complex segments and [Cd(mnt)2] complex segment bridged by S‐K‐S, S‐K‐N and N‐K‐N interactions between adjacent [K(18‐C‐6)] and [Cd(mnt)2] units.
Reductive Cleavage of the Te—Te Bond in Diphenyl Ditelluride by the Sm/CrCl3(cat.) System; Preparation of Telluroesters and Unsymmetrical Phenyltellurides
Authors: Liu Yun‐Kui , Zhang Yung‐Min 
Published: September 2010

AbstractThe reduction of diphenyl ditelluride by the Sm/CrCl3 (cat.) system led to a telluride anion. This species reacted with acid chlorides, alkyl halides, and α,β‐unsaturated enoates or α,β‐unsaturated ene nitrites to afford telluroesters and unsymmetrical phenyltellurides, respectively, in moderate to good yields under mild and neutral conditions.
Theoretical Study on Intermolecular Interactions and Thermodynamic Properties of Nitroamine Dimers
Authors: Ju Xue‐Hai , Xiao He‐Ming 
Published: September 2010

AbstractAb initio self‐consistent field (SCF) and Møller‐Plesset correlation correction methods employing 6‐31G* * basis set have been applied to the optimizations of nitroamine dimers. The binding energies have been corrected for the basis set superposition error (BSSE) and the zero‐point energy. Three optimized dimers have been obtained. The BSSE corrected binding energy of the most stable dimer is predicted to be ‐31.85 kJ/mol at the MP4/6‐31G* * /MP2/6‐31G* * level. The energy barriers of the Walden conversion for ‐ NH2 group are 19.7 kJ/mol and 18.3 kJ/mol for monomer and the most stable dimer, respectively. The molecular interaction makes the internal rotation around N1 ‐ N2 even more difficult. The thermodynamic properties of nitroamine and its dimers at different temperatures have been calculated on the basis of vibrational analyses. The change of the Gibbs free energy for the aggregation from monomer to the most stable dimer at standard pressure and 298.2 K is predicted to be 14.05 kJ/mol.
A Nitrilotriacetate Bridged Heteronuclear Co (II)‐Na (I) Polymer: {[CoNa (NTA) (H2O)3] · 2H2O}n
Authors: Hu Mao‐Lin , Lin Juan‐Juan , Miao Qian , Xiong Yi 
Published: September 2010

AbstractA novel Co (II) ‐ Na (I) heterometallic coordination polymer {[CoNa (NTA) (H2O)3] · 2H2O}n (NTA = nitrilotriacetate) was synthesized and characterized by elemental analysis and X‐ray diffraction study. The electrochemical behavior in aqueous solution was measured by cyclic voltammetry, indicating a quasi‐reversible process. The complex crystallizes in the orthorhombic space group Pbca with the cell parameters a = 1.47276 (3) nm, b = 0.97280 (3) nm, c = 1.92946 (6) nm, V = 2.76434 (13) nm3, Z = 8. In the title complex, there are two kinds of zigzag chains which interconnect together to form 2D network. One stretches along the b‐axis, comprising Co (II) ions, the other stretches along the c‐axis, comprising Na (I) ions.
New Supramolecular Complex Assembled through Hydrogen Bonds. Crystal Structure of Co (PMBP‐tsc)2 · 2DMF · 2H2O
Authors: Liu Lang , Jia Dian‐Zeng , Qiao Yong‐Min , Yu Kai‐Bei 
Published: September 2010

AbstractThe structure of the complex [Co (PMBP‐tsc)2 · 2DMF · 2H2O] (PMBP‐tsc = l‐phenyl‐3‐methyl‐4‐benzoylpyrazol‐5‐one‐thio‐semicarbazone) has been determined by X‐ray crystallography. It crystallizes in the orthorhombic system, space group Pna21, with lattice parameters a = 2.1170 (3) nm, b = 1.2780 (10) nm, c = 1.8956 (2) nm, V = 4.5258 (9) nm3 and Z = 4. The structure shows that Co2+ in the complex is hexa‐coordinated with a distorted octahedral coordination sphere. The water molecules bridge the adjacent stacks through hydrogen bonds and lead to supramolecular formation with three‐dimensional network structure.
Synthesis, Structure and Magnetic Properties of a Diphenoxo‐bridged Binuclear Copper (II) Complex
Authors: Xie Yong‐Shu , Jiang Hui , Xu Xiao‐Long , Liu Qing‐Liang , Du Chen‐Xia , Zhu Yu 
Published: September 2010

AbstractA mixed‐ligand copper (II) complex [Cu2 (phen)2 (HL1)2] ‐ (ClO4)2 (I) was synthesized. X‐ray analyses reveal that 1 has a bis (μ2‐phenoxo)‐bridged dicopper (II) structure. 2D hydrogen‐bonded network is formed utilizing the N‐H, O‐H and C‐H groups of the (HL1)− ligands (H2L1 = N‐(2‐hydroxybenzyl) ethanolamine), the C‐H groups of the phenanthrolines and the perchlorate anions. Variable temperature magnetic properties of 1 have shown comparatively weak antiferromagnetic interactions with respect to the bridge angles, which have been ascribed to the unfavorable overlaps of the magnetic orbitals for the highly distorted copper coordination polyhedra and the pyramidal distortions at the phenoxo oxygen atoms.