bluuebunny/crossref_metadata_2025 huggingface dataset:
Enantioselectivity of Photochemical Reactions within Polymer Microcapsules
Authors: Lei Ma , Li‐Zhu Wu , Li‐Ping Zhang , Chen‐Ho Tung
Published: September 2010

Polymer microcapsule was employed as a reaction medium to achieve enantioselectivity in photochemical reduction of phenyl cyclohexyl ketone and photoelectrocyclization of tropolone methyl ether under the influence of various chiral inductors. In all cases, low but evident enantioselectivity was observed. The poor enantioselectivity is probably due to the facts that not all the capsules include simultaneously both the chiral inductor and the reactant molecules, and the wall of the microcapsule is not rigid enough to hold the reactant and the chiral inductor molecules in close contact.
Mesoscopic Simulation of Aggregates in Surfactant/Oil/Water Systems
Authors: Shi‐Ling Yuan , Zheng‐Ting Cai , Gui‐Ying Xu
Published: September 2010

The aggregates in sodium dedecylsulphate (SDS)/dimethylbenzene/water systems have been investigated using dissipative particles dynamic (DPD) simulation method. Through analyzing three‐dimensional structures of aggregates, three simulated results are found. One is the phase separation, which is clearly observed by water density and the aggregates in the simulated cell; another is the water morphology in reverse micelle, which can be found through the isodensity slice of water including bound water, trapped water and bulky water; the third is about the water/oil interface, i. e., ionic surfactant molecules, SDS, prefer to exist in the interface between water and oil phase at the low concentration.
Isomerization Mechanisms of C5H2 on the Triplet and Singlet Potential Energy Surfaces
Authors: Cong‐Jie Zhang , Li‐Ling Zhang , Ze‐Xing Cao , Qian‐Er Zhang
Published: September 2010

Density functional theory calculations with the B3LYP functional are used to study the structure and stabilities of C5H2 isomers and possible isomerization mechanisms on the triplet and singlet potential energy surfaces. Calculated results show that isomerization of C5H2 is likely to occur on the triplet potential energy surface while direct conversions of the singlet C5H2 isomers via 1,3‐hydrogen migration transition states are extremely difficult dynamically. In such isomerization processes, the hydrogen transfer processes in carbon chains are the rate‐determining steps. The triplet species except the linear ground state X3 Σ are rather less stable than their singlet forms, although the singlet and triplet species have similar geometries.
Theoretical Study on the Structures and Stability of Isomers and Complex of [Si, C, O, O] System
Authors: Hai‐Tao‐C Yu , Bo Li , Yu‐Juan Chi , Hong‐Gang Fu , Ze‐Sheng Li , Jia‐Zhong Sun
Published: September 2010

A detailed singlet potential energy surface (PES) of [Si, C, O, O] system including a van der Waals (vdW) complex SiO CO, eight isomers, and twelve transition states is investigated by MP2 and QCISD(T) (single‐point) methods. At the final QCISD(T)/6–311 + G(2df)//MP2/6–311G(d) level with zero‐point energy included, the complex SiO‐CO is found to be thermodynamically and kinetically the most stable species. Although eight isomers are located as local energy minima, they are rather unstable toward isomerization to the dissociation fragments or complex. For the reaction of silicon atoms with carbon dioxide, two competitive reaction channels are found, and the primary pathway, which leads to the products of SiO and CO fragments, is the direct oxygen‐abstraction process from carbon dioxide by silicon atom with a 41.16 kJ/mol reaction barrier height. Our predications are in good agreement with previous experimental and theoretical studies.
Synthesis, Characterization, Thermal Decomposition Mechanism and Non‐Isothermal Kinetics of the Pyruvic Acid‐Salicylhydrazone and Its Complex of Praseodymium (HE)
Authors: Shui‐Yang He , Yu Liu , Jian‐She Zhao , Hong‐An Zhao , Rui Yang , Rong‐Zu Hu , Qi‐Zhen Shi
Published: September 2010

The pyruvic add‐salicylhydrazone and its new complex of Pr(III) were synthesized. The formulae C10H10N2O4(mark as H3L) and [Pr2(L)2(H2O)2]·3H2O (L= the triad form of the pyruvic acid‐salicylhydrazone [C10H7N2O4]3‐) were determined by elemental and EDTA volumetric analysis. Molar conductance, IR, UV, X‐ray and1H NMR were carried out for the characterizations of the complex and the ligand. The thermal decompositions of the ligand and the complex with the kinetic study were carried out by non‐isothermal thermogravimetry. The Kissinger's method and Ozawa's method are used to calculate the activation energy value of the main step decomposition. The stages of the decompositions were identified by TG‐DTG‐DSC curve. The non‐isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equation were investigated by comparing the kinetic parameters.
Synthesis and Crystal Structures of Three Ladder Distannoxane Dimers [(PhCH2)2(Cl)SnOSn(X) (CH2Ph)2]2 (X = Cl, OMe, OEt)
Authors: Chun‐Lin Ma , Feng Li
Published: September 2010

Three distannoxane dimers [(PhCH2)2(Cl)SnOSn(X) (CH2Ph)2]2 (X = Cl, OMe, OEt) were prepared by the hydrolytic reaction of (PhCH2)2SnCl2 with sodium alkoxides. The compounds are assigned tetranuclear distannoxane structures in solid state, which contain the so‐called ladder arrangement with a central planar Sn2O2 four‐membered ring. The endo‐and exo‐cyclic Sn atoms are both five‐coordinate, and have distorted trigonal bipyramidal geometries. A variety of hydrolyses of (PhCH2)2SnCl2 were performed and these dimers were characterized by IR, 1H NMR spectroscopy and X‐ray diffraction analysis.
Flow‐injection Chemiluminescence Determination of Reserpine in Medicine and Biological Fluids with Controlled‐Reagent‐Release Technology
Authors: Zheng‐Hua Song , Ni Zhang
Published: September 2010

A sensitive and rapid chemiluminescence (CL) flow injection with controlled‐reagent‐release technology for the determination of reserpine was proposed. The CL reagents, luminol and dichromate, used in this sensor, were all immobilized on anion‐exchange resin. Through injection of 100 μL of water, the reagents on the anion‐exchange resin column were eluted and in the presence of reserpine, the CL intensity was decreased, by which reserpine could be sensed. Reserpine was quantified by measuring the decrement of CL intensity, which was observed linear with the logarithm of reserpine concentration in the range of 1.0–500.0 ng/mL, and the limit of detection was 0.4 ng/mL (3σ) with a relative standard deviation of less than 3.0%. The proposed procedure was applied in the assay of reserpine in pharmaceutical preparation and biological fluids without any pre‐treatment process and with sampling frequencies of 72 times per hour.
A Direct Evidence of Stoichiometric Displacement between Insulin and Methanol in Reversed Phase Liquid Chromatography
Authors: Xin‐Du Geng , Fred E. Regnier
Published: September 2010

With four kinds of mobile phases, methanol‐water, ethanol‐water, 2‐propanol and acetonitrile‐water (all containing 0.1% trifluroacetic acid), the displacement between solute and solvent in RPLC was proved to be universal in frontal analysis (FA). Based on the measured Z value in usual RPLC to be a constant and the quantitative determination of methanol increment in mobile phase in FA, the stoichiometric displacement (SD) between insulin and methanol was directly proved by the experiment. The SD was also proved to occur only on about the one‐fourth of the maximum amount of adsorbed methanol in the bonded phase layer (BPL) without any dynamic problem of mass transfer, while in FA, the SD firstly occurs on the surface of the BPL and then gradually sinks into the deeper sites companied with a dynamic problem. Although the displaced solvent by the same solute is less in the former case, the SD is independent of how deep of the solute enters the BPL. In addition, the adsorbed amount of solute on an adsorbent not only depends on the numbers of the adsorbed layer on the adsorbent surface, but also on the extent of me complete removal of the displace‐able solvent in the BPL. The physical fundamental of the SD and the methodology for investigation were also discussed.
A Novel Fluorescent Reagent for Analysis of Hydrogen Peroxide
Authors: Su‐Ying Dong , Mei‐Hong Su , Li‐Hua Nie , Hui‐Min Ma
Published: September 2010

8‐(4,6‐Dichloro‐1,3,5‐triazinoxy)quinoline (DTQ) was evaluated as a new fluorescent reagent for determining hydrogen peroxide. It was found that the fluorescence intensity of DTQ in alkaline medium could be dramatically enhanced upon addition of H2Q2. Based on this effect, a simple and selective method for the spectrofluorimetric determination of hydrogen peroxide was established. The relative standard deviation of the method was found to be 1.1% for 9 replicate determinations of a 4.6 × 10–6 mol/L hydrogen peroxide solution. The linear range was 2.3 × 10–7—2.3 × 10–5 mol/L with a detection limit of 2.2 × 10–8 mol/L (S/N = 3). The method was attempted to determine hydrogen peroxide in synthetic human serum samples with satisfactory results.
Tuning the Excited‐state Properties of Cyclometalated Platinum (II) Complexes of 6‐Phenyl‐2,2′‐bipyridine by Ancillary Acetylide Ligand
Authors: Zi‐Xin Wu , Li‐Zhu Wu , Qing‐Zheng Yang , Li‐Ping Zhang , Chen‐Ho Tung
Published: September 2010

A series of luminescent cyclometalated platinum (II) complexes, (CNN)Pt(CC̊) [HCNN = 4‐(4‐tolyl)‐6‐phenyl‐2,2′‐bipyridine; R = 4‐chlorophenyl (1), phenyl (2) and 4‐tolyl (3)], were synthesized, and their spectroscopic properties have been examined. These complexes are brightly emissive both in fluid solution and in the solid state, attributed to triplet metal‐to‐ligand charge transfer (3MLCT) state. The excited state energy can be tuned by ancillary acetylide ligands. The emission lifetimes in dichloro‐methane solution at room temperature were up to 1.64 μs and the emission quantum yields were in the range of 0.03–0.15.
Optical Rotatory Feature of (R or S)‐1, 1′‐Binaphthalene‐2, 2′‐diol (BINOL) in Various Solvents
Authors: Chuan‐Fu Chen , Zhong Li , Min Ai , Yong‐Ming Chen , Fu Xi
Published: September 2010

The changes of the specific rotation and sign of optically active BINOL have been studied in polar/non‐polar solvents and at the different pH values of solvent. It is considered that these changes are determined by the equilibrium studies between cisoid and transoid conformations of BINOL with the same configuration (R or S) which related to the change of the dihedral angle between two naphthalene ring planes of BINOL.
Construction of CdS Nanoparticle Chain on DNA Template
Authors: Jian Jin , Lin Jiang , Xia Chen , Wen‐Sheng Yang , Tie‐Jin Li
Published: September 2010

Salmon sperm DNA was used as template to assembly and nucleate CdS nanoparticles. Transmission electron microscopy (TEM) images showed that the CdS nanoparticles formed unique nanostructure which present regular and parallel chains along DNA molecular chain. The width of every chain was about 3 nm. Raman and X‐ray photoelectron energy spectroscopy (XPS) confirmed that the nucleation sites of CdS nanoparticles were phosphate acid groups of DNA.
Preparation of Aromatic Amines by Reduction of Aromatic Nitro Compounds with Metallic Tellurium in Near‐Critical Water
Authors: Lei Wang , Pin‐Hua Li , Zhao‐Qin Jiang
Published: September 2010

Aromatic amines were prepared in good yields by a novel reduction of aromatic nitro compounds with tellurium metal in near‐critical water at 275°C.
Low Temperature Synthesis and Characterization of Li1.2‐yNayV3O8 (0 ≤ y ≤ 1.2) from V2O5 Gel
Authors: Jing‐Gang Xie , Jle Xiao , Hui Zhan , Yun‐Hong Zhou
Published: September 2010

Without overnight heating and stirring, Li1.2V3O8 and its analogs Li1.2‐yNayV3O8 (0 ≤ y ≤ 1.2) were successfully synthesized by adding mixed solution of LiOH and NaVO3 to V2O5 gel and dehydrating the prepared gel in 150–350°C. The simplicity awards this synthesis process superiority over other low temperature synthesis routes when mass production is concerned. TG‐DTA, XRD and TEM experiments were carried out for physical characterization. By galvanostatic charge‐discharge and cyclic voltammetry tests, these products showed better electrochemical performance than high temperature products as cathode active materials in secondary lithium batteries. After treatment of Li1.2V3O8 at 250°C, it exhibited a capacity of 350 mAh/g when cycled at current rate of about 60 mA/g over the voltage range of 3.8–1.7 V vs. Li+/Li. The influence of partial substitution of Li by Na was also extensively studied.
Study on Synthesis and Electrochemical Properties of Nanophase Li‐Mn‐spinel
Authors: Chuan‐Qi Feng , Ke‐Li Zhang , Ju‐Tang Sun , Hao Tang
Published: September 2010

Li‐Mn‐spinel was synthesized using the rheological phase reaction method. First, the precursor was prepared by rheological phase reaction. Then it was decomposed to form Li‐Mn‐spinel, which was characterized by X‐ray diffraction analysis and IR spectra. The particle size of Li‐Mn‐spinel was determined by the method of the transmission electron microscopy. The synthesized materials are of nanometer size with 30—100 nm in the average diameter. The electrochemical properties of the Li‐Mn‐spinel were also studied. It proved that this method not only provided a simple practicable and effective route for the synthesis of Li‐Mn‐spinel, but also had many advantages such as lower sintering temperature, shorter sintering time, fine particles and particularly excellent electrochemical performances.
A Sensitive Fluorescence Quenching Method for the Determination of Iron (II) with 1,10‐Phenanthroline
Authors: Guang‐Hua Zhu , Huang‐Xian Ju , Bao‐Fen Ye
Published: September 2010

A sensitive and selective fluorescence quenching method for the determination of Fe2+ with 1,10‐phenanthroline was developed. The fluorescence intensity of 1,10‐phenanthroline at λex of 266 run and λem of 365 nm was constant in the range of pH 4.0 to 10.0 and decreased linearly upon addition of Fe2+ to its solution. This decrease was mainly due to a static quenching effect caused by the formation of a non‐fluorescent complex of Fe2+ with 1, 10‐phenanthroline. The total amount of iron was determined by using hydroxylamine hydrochloride to reduce Fe3+ to Fe2+. The linear range was from 5.0 × 10–7 to 2.0 × 10–5 mol/L with a detection limit of 2.4 × 10–8 mol/L at 3s̀. The quenching constant of Fe2+ to 1,10‐phenanthroline was calculated to be (5.70 × 0.05) × 104 L/mol at 25 °C. Effects of foreign ions on the determination of Fe2+ were investigated. The results of the new method for the determination of iron in tap water and natural water samples were in good agreement with those obtained by graphite atomic absorption spectrometry.
Evaluation of Bioeffects of a Long‐term Administering Change on Rat by Proton NMR Method and Biochemical Examination
Authors: Jiang‐Hua Feng , Xiao‐Jing Li , Feng‐Kui Pei , Yu‐Xiu Niu
Published: September 2010

High resolution1H nuclear magnetic resonance (NMR) spectroscopy has been employed to assess long‐term toxicological effects of ChangLe (a kind of rare earth complex applied in agriculture). Male Wistar rats were administrated orally with ChangLe at doses of 0, 0.1, 0.2, 2.0, 10 and 20 mg/kg body weight daily, respectively, for 6 months. Urine was collected at day 30, 60, 90 and serum samples were taken after 6 months. Many low‐molecular weight metabolites were identified by1H NMR spectra of rat urine. A decrease in citrate and an increase in ketone bodies, creatinine, DMA, DMG, TMAO, and taurine in the urine of the rats receiving high doses were found by1H NMR spectra. These may mean that high‐dosage of ChangLe impairs the specific region of liver and kidney, such as renal tubule and mitochondria. The decrease in citrate and the increase in succinate and α‐ketoglutarate were attributed to a combination of the inhibition of certain citric acid enzymes, renal tubular acidosis and the abnormal fatty acid catabolism. The information of the renal capillary necrosis could be derived from the increase in DMA, DMG and TMAO. The increase in taurine was due to hepatic mitochondria dysfunction. The conclusions were supported by the results of biochemical measurements and enzymatic assay. No obviously toxicological effects on metabolism were found for low‐dosage ChangLe, but further studies on safety of ChangLe applied to agriculture are still required.
A Rapid and Efficient Biginelli Reaction Catalyzed by Zinc Triflate
Authors: Hui Xu , Yan‐Guang Wang
Published: September 2010

An efficient and practical procedure for the synthesis of dihydropyrimidinones from aldehydes, 1,3‐dicarbonyl compounds and urea under solvent‐free reaction condition using zinc triflate as a catalyst is described. In comparison with the classical Biginelli reaction, the yields for this new procedure increased from 20%—50% to 75%— 98% while the reaction time was significantly shortened from 18 h to 20 min.
A Density Functional Theory Study on Electronic Structure and Second‐order Nonlinear Optical Properties of Some Push‐Pull Molecules
Authors: Rong‐Jian Sa , Ke‐Chen Wu , Chen‐Sheng Lin , Ping Liu , Chao‐Yong Mang
Published: September 2010

Time‐dependent density‐functional theory (TDDFT) has been applied to calculate the electronic structure and second‐order nonlinear optical (NLO) properties of some organic molecules. The two‐dimensional (2‐D) charge transfer characteristics of calculated molecules were studied and compared with corresponding experimental results. All the theoretical results agree well with the measurement. For 2‐D molecule with two‐fold symmetry, the dominant charge transfer is off‐diagonal, while for three‐fold symmetry 2‐D molecule, the dominant charge transfer is not only between branches and central group but also among branches.
Studies on Structure and Electrocatalytic Hydrogen Evolution of Nanocrystalline Ni‐Mo‐Fe Alloy Electrodeposit Electrodes
Authors: Ling Huang , Fang‐Zu Yang , Shi‐Gang Sun , Shu‐Kai Xu , Shao‐Min Zhou
Published: September 2010

Nanocrystalline Ni‐Mo‐Fe alloy deposits were obtained by electrode‐position. The structures of the alloy deposits were analyzed by X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS). The XRD results of nanocrystalline Ni‐Mo‐Fe alloy deposit show that many diffraction lines disappear, and that there is only one diffraction peak at 44.0°. The XPS results of nanocrystalline Ni‐Mo‐Fe alloy deposits indicate that the nickel, molybdenum and iron of the deposits exist in metallic state, and that the binding energy of the alloyed elements increases to some extent. The nanocrystalline Ni‐Mo‐Fe alloy deposit electrode may offer better electrocatalytic activity than the polycrystalline nickel electrode and the nanocrystalline Ni‐Mo alloy electrode. The electrochemical impedance spectra from the nanocrystalline Ni‐Mo‐Fe alloy electrode indicate that hydrogen evolution in 30% (m/m) KOH at lower overpotential is in accordance with the Vohner‐Tafel mechanism, but with the Vohner‐Heyrovsky mechanism at higher overpotential.
In situ Observation of the Photochromism in the Langmuir Monolayer of a Non‐typical Amphiphilic Spiropyran Derivative at the Air/Water Interface
Authors: Hao‐Fei Gong , Ji‐An Tang , Ming‐Hue Liu , Cong‐Min Wang , Mei‐Gong Fan
Published: September 2010

In situ photochromic process in the monolayer of a photochromic spiropyran derivative without long alkyl chain, was investigated. The photochromism at the air/water interface under different surface pressures was studied by surface pressure‐area isotherms, surface pressure‐time curves, area‐time curves and Brewster angle microscopy. Both forms of the compound were found to form monolayers at the air/water interface although it does not have long alkyl chain. A large area expansion in the monolayer corresponding to a zeroth order reaction was found at the initial stage of the UV light irradiation. A series of dynamic investigations revealed that at high pressure after phase transition in the monolayer, the surface pressure changes greatly under alternative irradiation of UV and visible light An obvious morphological change accompanying with the photochromism was observed in situ.
Heat Capacities and Thermodynamic Properties of Lanthanum/Holmium Perchlorate Complexes with Glycine
Authors: Bei‐Ping Liu , Zhi‐Cheng Tan , Hua‐Guang Yu , Li‐Xian Sun , Xiao‐Zheng Lan , You‐Ying Di , Zhen‐Gan Chen , Ping Liu
Published: September 2010

The heat capacities of the two complexes, [La2(Gly)6(H2O)4]‐(ClO4)6 and [Ho2(Gly)4(H2O)4](ClO4)6·2H2O (Gly = glycine), were measured by adiabatic calorimetry in the temperature range from 78 to 375 K. A solid‐solid phase transition was found between 322.87 and 342.29 K for [Ho2(Gly)6(H2O)4](ClO4)6·2H2O, and the peak temperature, the enthalpy and the entropy of the transition were obtained to be 330.94 K, 11.65 kJ·mol−1 and 35.20 J· K−1·mol−1, respectively. No indication of any phase transition or thermal anomaly was observed for [La2 (Gly)6 (H2O)4 ] (ClO4)6. Thermal stabilities of the two complexes were investigated by thermogravimetry in the temperature range of 40–800°C. The possible mechanisms for the thermal decompositions were proposed according to the TG and DTG curves.
Hydrothermal Synthesis and Structure of a New 3D Lanthanide‐Carboxylate Framework, [La(btec)1/2 (H2btec)1/2 (H2O)]n (H4btec = 1,2,4,5‐Benzenetetracarboxylic acid)
Authors: Dao‐Feng Sun , Wen‐Hua Bi , Rong Cao , Xing Li , Qian Shi , Mao‐Chun Hong
Published: September 2010

The title complex, [La(btec)1/2(H2btec)1/2 (H2O)]n (H4btec= 1, 2,4,5‐benzenetetracarboxylic acid) (1) was synthesized by the hydrothermal reaction of 1,2,4,5‐benzenetetracarboxylic dianhydride with La(NO3)3·6H2O in H2O, and crystallizes in the triclinic system, space group P‐1 with a = 0.64403(3) nm, b = 0.94500(4) nm, c = 0.96380(5) nm, a = 88.535(2)°, β = 100.314(2)°, γ = 76.6470(10)°, V = 1.60968(10) nm3, Z = 2, and final R = 0.0274, Rw = 0.0735. In 1, each La(m) ion is coordinated by eight oxygen atoms from six carboxylate groups and one coordinated water molecule. Two different coordination modes of H4btec were present in the structure, one of which contains two protonated carboxylate groups to balance the charge.
Synthesis, Characterization and Crystal Structures of Lanthanide Phenoxyacetate Complexes with 1,10‐Phenanthroline
Authors: Hong Deng , Yue‐Peng Cai , Hui Chao , Chun‐Long Chen , Cai‐Wu Jiang , Liang‐Nian Ji , Chao‐Qiu Chen
Published: September 2010

Three new lanthanide phenoxyacetate complexes with 1,10‐phenanthroline. [Nd(POA)3 (phen)]2 · 2C2H5OH (1), [Eu(POA)3‐ (phen)]2 · 2C2H5OH (2) and [Sm(POA)2(DMSO)(phen)]2‐ (ClO4)2 (3) (POA= phenoxyacetate, phen = 1,10‐phenanthroline, DMSO = dimethyl sulfoxide), were synthesized and characterized by elemental analyses, IR, UV‐vis and FAB‐MS spectra. Their structures were determined by single crystal X‐ray diffraction analysis. In complexes 1 and 2, the carboxylate groups are bonded to Ln3+ ion in three modes: the chelating bidentate, the bridging bidentate and the bridging tridentate. In complex 3, the carboxylate groups are bonded to Sm3+ ion only involved in one mode: the bridging bidentate. The luminescence behavior of complex 2 was also studied by means of emission spectra.
Sonogashira Coupling Reaction with Palladium Powder and Potassium Fluoride in Methanol
Authors: Lei Wang , Pin‐Hua Li
Published: September 2010

A Sonogashira coupling reaction of aromatic halides with terminal alkynes in the presence of palladium powder, potassium fluoride, cuprous iodide and triphenylphosphine in methanol, giving the corresponding coupling products aryl alkynes in good to excellent yields, was investigated.
Ethylene Oligomerization by 8‐Aminoquinoline Nickel Dichloride Complex Supported on β‐Cyclodextrin#
Authors: Yong Chen , Ning Zhu , Zi‐Long Li , Wen‐Hua Sun
Published: September 2010

β‐Cyclodextrin was pretreated by methylaluminoxane (MAO) and subsequently reacted with 8‐aminoquinoline nickel dichloride complex to yield the supported catalyst, which was characterized by ICP, IR and XPS methods. Using MAO as cocatalyst, the catalytic activity of this supported catalyst was investigated at various reaction temperature and AI/Ni molecular ratio. The results showed that, despite possessing a number of polar groups, the supported catalyst displayed relatively high activity over 1 × 105 g ethylene/(mol Ni·h) under mild conditions.
Synthesis, Crystal Structure and Magnetic Properties of a 1‐D Polymer, [Cu(NITpPy)2(H2TCB)(H20)]·2H2O
Authors: Li‐Ya Wang , Li‐Cun Li , Dai‐Zheng Liao , Zong‐Hui Jiang , Shi‐Ping Yan
Published: September 2010

A novel complex [Cu(NnpPy)2(HlTCB)(H1O)]·2H2O (NITpPy = 2‐(pyrid‐4′‐yl)‐4,4,5,5‐tetramethyl‐1, 3‐dioxoimidazoline; H2TCB = 1, 5‐dicarboxybenzene carboxylic‐2, 4‐diacid) has been synthesized and characterized by X‐ray crystallography analysis. The crystal structure consists of infinite chains of Cu‐(NITpPy)2(H2O) units linked by H2TCB ligands. The complex crystallizes in triclinic system with space group PI. Crystal data: a = 1.0594(2) nm, b = 1.3830(3) nm, c = 1.5551(3) nm, a = 67.75(3)°, β = 89.83(3)°, γ = 70.54(3)°. The variable magnetic susceptibility studies lead to magnetic coupling constant values of J1= −11.18 cm‐1 (Cu—Rad) and J2 = −4.06 cm−1 (Cu—Cu).
Synthesis and Crystal Structure of Two One‐dimensional Chain Copper Complexes [Cu(TTA)2(4,4′‐azpy)] and [Cu(TTA)2(3,3′‐azpy)]
Authors: Bao‐Long Li , Jian‐Ping Lang , Jing Chen , Yong Zhang , Li‐Min Zheng
Published: September 2010

Two copper complexes [Cu(TTA)2(4,4′‐azpy)] (1) and [Cu‐(TTA)2(3,3′‐azpy)] (2) (HTTA = 1,1,1‐trifluoro‐3‐(2‐thenoyl)‐acetone, 4,4′‐azpy = 4,4′‐azobispyridine, 3,3′‐azpy = 3,3′‐azobispyridine) were synthesized and characterized. The crystal structures were determined by X‐ray diffraction analysis. The crystal 1 belongs to triclinic with space group P1, a = 0.8515(2) nm, b = 0.9259(2) nm, c = 0.9468(2) nm, a = 66.126(9)°, β = 79.667(9)°, γ = 90.13(1)°, Z = 1, V = 0.6692(2) nm3, Dc = 3.425 g/cm3, γ = 2.113 mm−1, F(000) = 694, R1 = 0.0594, wR2 = 0.1499. The crystal 2 belongs to monoclinic with space group P21/c, a = 1.0661(2) nm, b = 1.4296(3) ran, c = 1.0041(3) nm, β = 114.50(3)°, V = 1.3926(5) nm3, Z = 2, Dc = 1.646 g/ cm3, μ = 1.015 mm−1, F(000) = 694, R1, = 0.0535, wR2 = 0.1113. In the crystals of complexes 1 and 2, the copper atoms have distorted octahedral symmetry. The two compounds possess very similar one‐dimensional linear chains linked through the rodlike 4,4′‐azpy ligands or 3,3′‐azpy ligands.
Application of Single‐labelled Probe‐primer in PCR Amplification to the Detection of Hepatitis B Virus DNA
Authors: De‐Ming Kong , Han‐Xi Shen
Published: September 2010

A new method based on the incorporation of a single‐labelled probeprimer into polymerase chain reaction (PCR) for the detection of PCR‐amplified DNA in a closed system is reported. The probeprimer consists of a specific probe sequence on the 5′ ‐end and a primer sequence on the 3′‐end. A fluorophore is located at the 5′‐end. The primer‐quencher is an oligonucleotide, which is complementary to the probe sequence of probe‐primer and labelled with a quencher at the 3′‐end. In the duplex formed by probe‐primer and primer‐quencher, the fluorophore and quencher are kept in close proximity to each other. Therefore the fluorescence is quenched. During PCR amplification, the specific probe sequence of probe‐primer binds to its complement within the same strand of DNA, and is cleaved by Taq DNA polymerase, resulting in the restoration of fluorescence. This system has the same energy transfer mechanism as molecular beacons, and a good quenching efficiency can be ensured. Following optimization of PCR conditions, this method was used to detect hepatitis B virus (HBV) DNA in patient sera. This technology eliminates the risk of carry‐over contamination, simplifies the amplification assay and opens up new possibilities for the real‐time detection of the amplified DNA.
A Novel Catalyst for Isobutene Oligomerization to High Quality Gasoline
Authors: Peng Zhou , Zeng‐Jian An , Tian‐Xi Cai , Xi‐Gao Jian
Published: September 2010

Dimerization of isobutene in liquid state to form high‐octane value gasoline components was investigated over a homemade novel ion exchange resin, SPPESK, which shows high activity and selectivity in isobutene dimerization under mild conditions.
Interaction and Interfacial Molecular Recognition of Calix [4] arene Derivatives Bearing Nucleobases for Complementary Nucleoside
Authors: Zhen‐Sheng Wang , Guo‐Yuan Lu , Xin Sheng , Xun Guo , Chuan‐Ming Jin
Published: September 2010

The p‐tert‐butyl calix[4] arene derivatives la with uracils and lb with adenines at the lower rim were synthesized. The Interaction between la and lb in CDCl3 solution was demonstrated by 1H NMR spectra. The interfacial molecular recognitions of la and lb for the complementary nucleosides in aqueous subphases were investigated by Langmuir‐Blodgett technique.
Synthesis of Chlorin‐enediyne Dyads by Palladium‐catalyzed Coupling Reaction
Authors: Jin‐Jun Wang , Jun‐Gang Yin , Xu‐Ran Wu , Yan Zhao , Bao‐An Gong , Guang‐Fan Han , Key Shim Young
Published: September 2010

Methyl 9‐ethylenedioxpyropheophorbide‐d was prepared from methyl pyropheophorbide‐a by protection of cyclic ketone with ethylene glycol, and oxidation with OsO4 in vinyl group at 2‐position. The terminal alkyne was introduced into chlorin chromophore by Grignard reaction, and the enediyne moiety was constructed by a palladium‐catalyzed coupling reaction with (Z)‐chloroenynes.
Microcalorimetric Studies of the Toxic Action of La3+ on Halobacterium Halobium R1 Growth
Authors: Peng Liu , Yi Liu , You‐Gui Chen , Song‐Sheng Qu , Zhi‐Xiong Xie , Ru‐Ming Zhao , Ping Shen
Published: September 2010

A microcalorimetric technique was used to evaluate the influence of La3+ on Halobacterium halobium Rl growth. By means of LKB‐2277 bioactivity monitor, ampoule method at 37 °C, the thermogenic curves of Halobacterium halobium R1 growth were obtained. In order to analyze the results, the maximum power Pm and the growth rate constants k were determined, showing that values of Pm and k are linked to the concentration of La3+. Addition of low concentration of La3+ can cause a decrease of the maximum heat production and growth rate constant. However, high concentration of La3+ may promote growth of Halobacterium halobium R1, but at much higher concentration of La3+, the growth of Halobacterium halobium R1 is inhibited again. For comparison, the shapes of Halobacterium halobium R1 cell were observed by means of transmission electron microscope. According to the thermogenic curves and TEM photos of Halobacterium halobium R1 under different conditions, it is clear that metabolic mechanism of Halobacterium halobium R1 growth is changed with the addition of La3+.
One‐pot Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐one Using TsOH as a Catalyst under Microwave Irradiation
Authors: Shn‐Jiang Tu , Fang Fang , Chun‐Bao Miao , Hong Jiang , Da‐Qing Shi
Published: September 2010

A series of Biginelli compounds was synthesized using TsOH as a catalyst under microwave irradiation. This simple method provided the title compounds in 86%–98% yields by the reaction of aromatic aldehydes with 1,3‐carbonyl compound and urea. The structure of 4o was determined by single crystal X‐ray diffraction analysis.
CD Spectroscopic Study on the Molecular Recognition of Chiral Salen‐Metal Complexes
Authors: Liu Tao , Ruan Wen‐Juan , Nan Jing , Zhu Zhi‐Ang
Published: September 2010

The molecular recognition behavior of the chiral salen‐metal complexes towards guest molecules, such as imidazole derivatives and amino‐acid ester, was systematically investigated by means of circular dichroism (CD) spectra. The coordination numbers of the host‐guest complexes as well as the recognition capability of the salen‐metal complexes were explained by character and intensity analyses of the CD spectra.
Mercaptolysis of the E/F Rings of Steroidal Sapogenins: A Concise Synthesis of Δ20(22)‐Furostene‐26‐thioethers
Authors: Tian Wei‐Sheng , Guan Hui‐Ping , Pan Xin‐Fu
Published: September 2010

Lewis acid catalyzed mercaptolysis of steroidal sapogenins was reinvestigated. Besides obtaining the reported 26‐thioacetals 5 under milder conditions, a new type of compounds Δ20(22)‐furostene‐26‐thioethers 6 were also synthesized through the mercaptolysis of steroidal sapogenins, which can be used to the synthesis of the steroidal molecule with side chains.
Studies Towards the Total Synthesis of Methyl Isosartortuoate: The Synthesis of a Cyclic Precusor of the Diene Unit
Authors: Liu Peng , Liao Xi‐Bin , Xu Xing‐Xiang
Published: September 2010

The preparation of the key intermediate 4 of the methyl isosartortuoate is described. The macrocyclization was completed through an intramolecular [2, 3]‐Wittig ring contraction. The four necessary stereogenic carbons were established by Sharp‐less asymmetric AE and AD reaction.
Sn‐Mediated Catalytic Asymmetric Reduction of Carbonyl Groups by Sodium Borohydride (or Sodium Borodeuteride)
Authors: Zhao Gang , Hu Jian‐Bing
Published: September 2010

Two remarkable reducing agents NaBH4 (or NaBD4)/SnCl2(or SnCl4·2Et2O) with chiral ligands are applied to the asymmetric reduction of carbonyl compounds with excellent chemical yields and enantioselective excesses.
Highly Chemical and Regio‐selective Catalytic Oxidation with a Novel Manganese Catalyst
Authors: Liu Bin , Chen Yi , Yu Cheng‐Zhi , Shen Zheng‐Wu
Published: September 2010

The chemical selectivity of a novel active manganese compound [MnIV/2μ‐O)3(TMTACN)2](PF6)2(1) in catalytic oxidation reactions depended on the structure of substrates and 1 was able to catalyze the oxidation of toluene into benzaldehyde and/or benzoic acid under very mild conditions. The following results were obtained; (1) The selectivity of the oxidation depended on the electronic density of double bonds. Reactivity was absent when strong electron‐witherawing groups were conjugated with double bonds. (2) Allylic oxidation reactions mostly take place when double bond is present inside a ring system, whilst epoxidation reactions occur when the alkene moiety is part of linear chain. (3) In ring systems, the methylene group was more likely to be oxidized than the methyl group on allylic position. As expected, the C—H bonds at the bridgeheads were unreactive. The secondary hydroxyl groups are more easily to be oxidized than the primary hydroxyl groups.
Asymmetric Syntheses Aided by Biocatalysts
Authors: Pei‐Ran Chen, , Jian‐Xin Gu, , Zbi‐Liang Wei, , Shi‐Qing Han, , Zn‐Yi Li, , Guo‐Qiang Lin,
Published: September 2010

This article summarizes the achievements of the authors' group in the area of biocatalyst‐catalyzed organic reactions in recent 10 years. A strain ofGeotrichumsp. obtained by screening is capable of stereoselectively reducing a number of carbonyl compounds. In many cases, the stereochemistry is complementary with that obtained by baker' s yeast. Therefore, this microorganism provides a useful pathway to the preparation of alcohol compounds with specific configurations. On the other hand, a number of plant sources have been screened for oxynitrilases and the hydrocyanation reactions of various arylcarboxaldehydes have been investigated. A “micro‐aqueous reaction system” was invented, by which a series of novel optically active cyanohydrins were prepared. On this basis, a high through‐put continuous reaction system has been designed. This paper also describes examples of the syntheses of bio‐active compounds by using the optically active compounds obtained from the above‐mentioned catalytic reactions as precursors.
Low Temperature Solvent Evaporation‐induced Crystallization Synthesis of Nanocrystalline TiO2 Photocatalyst
Authors: Jia‐Guo Yu , Jimmy C Yu
Published: September 2010

A novel and efficient methodology for obtaining highly active photocatalyst of bi‐phase TiO2 with small particle size and high specific surface area was developed by solvent evaporation‐induced crystallization (SEIC) method at low temperature. The prepared TiO2 powder was characterized with X‐ray diffraction (XRD), transmission electron microscopy (TEM) and BET surface areas. The photocatalytic activity was evaluated by the photocatalytic oxidation of acetone in air. The results showed that the photocatalytic activity of the TiO2 powder prepared by this method approached that of Degussa P25. This may be attributed to the fact that the prepared TIO2 powder had larger specific surface areas (265 nr2. g−1) and smaller crystallite size (about 5 nm), but relatively low crystallinity, as compared with Degussa P25.
Crystal Structure of Adduct 2‐Phenyl‐imidazo[4,5‐/]1,10‐phenanthroline Methanol
Authors: Hui‐Wen Lin , Wen‐Xiang Zhu
Published: September 2010

The structure of the title adduct comprises a phenanthroline derivative 2‐phenyl‐imidazo[4,5‐/]1,10‐phenanthroline and a methanol. The composition of the crystalline adduct was characterized as C19H12N4 CH3OH. It belongs to orthorhombic system, space group Pna21 with a = 1.3693(4) nm, b = 2.2988(7) nm, c =0.51338(15) nm, V = 1.6160(8) nm3, Z = 4, and final R1 = 0.0423, wR2 = 0.1012. Crystal structure shows that all the 19 carbon atoms and 4 nitrogen atoms are coplanar. The bond length data indicated that a very extensive conjugation system was formed. This conjugation makes the compound being a potentially excellent energy transformer used for luminescent materials.
Direct Electron Transfer between Glucose Oxidase and Multi‐walled Carbon Nanotubes
Authors: Jin‐Zhong Xu, , Jun‐Jie Zhu, , Qiang Wu, , Zheng Hu, , Hong‐Yuan Chen,
Published: September 2010

The direct electrochemical behavior between the glucose oxidase (GOD) and the multi‐walled carbon nanotubes (MWNTs) has been studied. Two pairs of cyclic voltammetric peaks corresponding to the two different processes, i.e. mass‐transport and surface reaction of GOD are observed on this MWNTs. The formal potentials with Eo' =‐0.45 V and Eo' =‐0.55 V were obtained respectively. The GOD film was observed on the carbon nanotube by the TEM.
Mineralization of 4‐Chlorophenol under Visible Light Irradiation in the Presence of Aluminum and Zinc Phthalocyaninesulfonates
Authors: Yi‐Ming Xü , Mei‐Qin Hu , Zu‐Xu Chen , Dong‐Yun Zeng
Published: September 2010

Photosensitized oxidation of 4‐chlorophenol (4CP) by the title complexes (AlPcS and ZnPcS) in aerated aqueous solution upon visible light irradiation (δ ≥ 450 nm) has been investigated using methanol as a disassociating reagent. It is confirmed that the monomeric species of the sensitizer is more active than the corresponding dimer in singlet oxygen generation for 4CP oxidation. However, the monomer is also the main component found in the sensitizer's photobleaching. In this regard, AlPcS is much more stable than ZnPcS, and the photobleaching is observed to proceed via singlet and triplet oxygen, respectively. The final products of 4CP oxidation in alkaline solution are carbon dioxide and chloride ions, while at pH = 7 and pH = 3 the p‐benzoquinone is the product. The temperature is found to have influence on both the photosensitized degradation of methyl orange and ZnPcS photobleaching, with an activation energy of 15.8 and 24.2 kJ/mol, respectively.
A Convenient Approach to the Enantiopure (15,25,45,55)‐and (1R,2S,4R,5S)‐2,5‐Bis(phenylmethyl)‐l,4‐diazabicyclo[2.2.2]‐octane
Authors: Li‐Hua Qiu, , Zong‐Xuan Shen, , Wu‐Hong Chen, , Yong Zhang, , Ya‐Wen Zhang,
Published: September 2010

Cyclodipeptide (3S, 6S)‐bis (phenylmethyl) piperazine‐2,5‐dione was prepared in high yield by heating phenylalanine methyl ester in toluene under reflux. The reduction of this cyclodipeptide with sodium NaBR4‐BF3 in DME gave the (2S, 5S)‐bis(phenylmethyl) piperazine, which, on heating with ethylene bromide and triethylamine, afforded the title compounds. This method was proved to be generally applicable to the synthesis of C2‐symmetric 2, 5‐disubstituted‐1, 4‐diazabicyclo [2. 2. 2] octane from the corresponding natural or unnatural amino add esters.
Silica Hybrid Containing (R)‐2,2′‐Binaphtho‐20‐crown‐6 Moieties via the Sol‐Gel Process
Authors: Yi‐Xiang Cheng, , Tian‐Dong Liu, , Ling‐Wu Chen,
Published: September 2010

(R)‐6,6′‐Bis (triethoxysilylethen‐2‐yl)‐2,2′‐binaphtho‐20‐crown6 (precursor, R‐2) derived from (R)‐2,2′‐BINOL derivative was synthesized by Pd‐catalyzed Heck reaction of (R)‐6,6′‐dibromo‐2, 2′‐binaphtho‐20‐crown‐6 (R‐1) intermediate with vinyltriethoxysilane. The hydrolysis and polycondensation of the precursor gave rise to the corresponding xerogel. Both precursor and xerogel were analysed by NMR, FT. IR, UV, CD spectra, fluorescent spectroscopy, polarimetry and elemental analysis. The precursor and xerogel can emit strong blue fluorescence and are expected to have the potential application in the separation of chiral molecules as fluorescent sensor. The precursor exhibits strong Cotton effect in its circular dichroism (CD) spectrum indicating that it is a highly rigid structure.
Heck reaction of iodoarenes with methyl acrylate catalyzed by cyclopalladated complexes of tertiary arylamines immobilized in ionic liquid [Bmim]+BF4−
Authors: Zheng Rui , Yang Fan , Zou Gang , Tang Jie , He Ming‐Yuan
Published: September 2010

Heck reaction of iodoarenes with methyl acrylate, catalyzed by cyclopalladated complexes of tertiary arylamines, was investigated in ionic liquid 1‐butyl‐3‐methy Imidazolium tetrafluoroborate ([Bmim] +BF4−). The products can be isolated conveniently from the ionic liquid‐catalyst system. The catalysts could be reused for more than 10 times still with satisfactory catalytic activity.
Conversion of N2O to N2 on MgO (001) surface with vacancy: A DFT study
Authors: Xu Yi‐Jun , Li Jun‐Qian , Zhang Yong‐Fan
Published: September 2010

The adsorption and decomposition of N2O at regular and defect sites of MgO (001) surface have been studied using cluster models embedded in a large array of point charges (PCs) by DFT/B3LYP method. The results indicate that the MgO (001) surface with oxygen vacancies exhibits high catalytic reactivity toward N2O adsorptive‐decomposition. It is different from the regular MgO surface or the surface with magnesium vacancies. Much elongation of O‐N bond of N2O after adsorption at oxygen vacancy site with O end down shows that O‐N bond has been broken with concurrent production of N2, leaving a regular site instead of the original oxygen vacancy site (F center). The MgO (001) surface with magnesium vacancies hardly exhibits catalytic reactivity. It can be concluded that N2O dissociation likely occurs at oxygen vacancy sites of MgO (001) surface, which is consistent with the generally accepted viewpoint in the experiments. The potential energy surface (PES) reflects that the dissociation process of N2O does not virtually need to surmount a given energy barrier.
Exponentially expanded grid network approach (EEGNA): An efficient way for the simulation of stiff electrochemical problems
Authors: Deng Zhao‐Xiang , Lin Xiang‐Qin , Tong Zhong‐Hua
Published: September 2010

The exponentially expanded space grid was incorporated into the network approach to overcome the problem of low simulation efficiency during the simulations of electrochemical problems with stiff kinetics or wide dispersion of diffusion coefficients, resulting in an effective electrochemical simulation method: exponentially expanded grid network approach (EEGNA). The stability and accuracy of the EEGNA for the simulation of various electrode processes coupled with different types of homogeneous reactions were investigated.
Microcalorimetric study of the action of Yb3+ ion on the growth of Staphylococcus aureus
Authors: Hou An‐Xin , Xue Zhi , Liu Yi , Qu Song‐Sheng
Published: September 2010

A microcalorimetric method was used to evaluate the action of Yb3+ ions on the growth metabolism of Staphylococcus aureus. The power‐time curves of the growth metabolism of Staphylococcus aureus and the action of Yb3+ ions were obtained by using stopped‐flow method at 37°C. For evaluation of the action, the growth rate constants (k1 and k2) for the log phase 1, log phase 2, and the total heat effect (Qtotal) for Staphylococcus aureus were determined. The results show that Yb3+ ions at low concentrations have the stimulatory effect on Staphylococcus aureus and that Yb* ions at higher concentration could inhibit its growth.
Synthesis, characterization and crystal structure of the first trinuclear MFe2(M = Cu and Ni) complexes based on nitroprusside
Authors: Zhou Bei‐Chuan , Kou Hui‐Zhong , Li Yong , Xiong Ming , Wang Ru‐Ji
Published: September 2010

Three new complexes [Ni(H2L)][Fe(CN)5(NO)]2 ± 6H2O (1), [Ni(H2L)][Fe(CN)5(NO)]2 ± 4H2O (2) and [Cu(H2L)][Fe‐(CN)5(NO)]2 ± 4H2O (3) (L = 3,10‐bis(2‐aminoethyl)‐1,3,5, 8,10,12‐hexaazacyclotetradecane) are prepared and characterized by IR, elemental analyses and single‐crystal X‐ray analyses, indicating that they are the first examples of trinuclear nitroprusside‐bridged MFe2 (M = Cu and Ni) complexes. In the three complexes, the central metal atoms (M) are all six‐coordinated by the nitrogen atoms from the macrocyclic ligand and two cyano‐bridges at the trans‐positions to form distorted octahedral configurations. The axial N‐M‐N linkage is nearly vertical to the equatorial plane defined by four coordinating N atoms of macrocyclic ligand. The C ± N‐Ni bond angle of 172.6° in complex 1 is apparently larger than those in complexes 2 and 3 (152.57° and 136.37°, respectively). The three complexes are all connected by hydrogen bonds into 3D networks. This study shows that the cyano‐bridged trinuclear species could be generated via the control of the charge of the building blocks.
Synthesis and structure of the first protonated zincoborophosphate: (H3O)Zn(H2O)2BP2O8·H2O
Authors: Shi Heng‐Zhen , Shan Yong‐Kui , He Ming‐Yuan , Liu Yn‐Yan , Weng Lin‐Hong
Published: September 2010

The solid acid of the first protonated zincoborophosphate, (H3O) Zn (H2O)2BP2O8·H2O (1), was soventothermally synthesized by the reaction of Zn(NO3)2 ± 6H2O and H3BO3 with H3PO4 in a mixed solvent, and structurally characterized by single‐crystal X‐ray diffraction analysis. It crystallizes in the hexagonal P6122, a = 0.9604(4) nm, c = 1.5297(6) nm, V = 1.2218(8) nm3, Dc = 2.921 g/cm3, Z = 6, F (000) = 1080, μ =3.495 mm−1. The structure features that the tetrahedra‐tetrahedra helices interconnected by octahedra and strong hydrogen bond interactions form a three‐dimensional framework. The protonated water molecules are located at unique positions. Other characterizations by IR and thermal analysis are also described.
P NMR studies on the ligand dissociation of trinuclear molybdenum cluster compounds
Authors: Li Zhao‐Ji , Qin Ye‐Yan , Tang Yan‐Hong , Kang Yao , Xia Ji , Chen Zhong , Wu Ling , Yao Yuan‐Gen
Published: September 2010

A series of carboxylate‐substituted trinuclear molybdenum cluster compounds formulated as Mo3S4(DTP)3(RCO2)(L), where R = H, CH3, C2H5, CH2Cl, CCl3, R1C6H4(R1 is the group on the benzene ring of aromatic carboxylate), L = pyridine, CH3CN, DMF, have been synthesized by the ligand substitution reaction. The dissociation of the loosely‐coordinated ligand L from the cluster core was studied by 31P NMR. The dissociation process of L is related to the solvent, temperature, and acidity of carboxylate groups, so as to affect the solution structure and reactive properties of the cluster. The long‐distance interaction between ligands RCO2 and L is transported by Mo3S4 core.