bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal Structure and EPR Spectra of cis‐Dioxo‐molybdenum(V) Complex with o‐Aminophenol
Authors: Lu Xiao‐Ming , Lu Jing‐Fen , Mao Xi‐An 
Published: September 2010

AbstractThe paramagnetic cis‐dioxo‐molybdenum(V) complex, [NH2CH2CH2NH3]3[MovO2(HNC6H4O)2] was obtained by the reaction of tetra‐butyl ammonium β‐octamolybdate with o‐aminophenol and ethylenediamine in the mixed solvent of CH3OH and CH3CN, and characterized by IR, NMR, EPR spectroscopy and X‐ray diffraction analysis. The determination of single crystal X‐ray analysis revealed that the central Mov ion metal center exhibits distorted octahedral coordination with cis‐dioxo o‐aminophenol. The EPR spectra of both the complex and flavoenzyme show similarly. Thus it suggests that the complex anion [MovO2(HNC6H4O)2]3‐ and flavoenzyme have related structure feature.
Sensitivity‐enhanced Experiments for the Measurement of J and Dipolar Coupling Constants
Authors: Lin Dong‐Hai , Liao Xin‐Li 
Published: September 2010

AbstractA sensitivity‐enhanced IPAP NMR experiment was described in this paper, which separates the 1H‐15N doublets into two different spectra to alleviate the problem of resonance overlaps and achieve the accurate measurement of J and residual dipolar coupling constants in proteins. This experiment offered 20%–60% sensitivity enhancement over the original IPAP experiment, and therefore produced more measurable resonances. Pulsed field gradient was used for coherence selection. Water‐flip‐back approach was used for water suppression. The sensitivity‐enhanced IPAP experiment was employed in the measurement of 1JNH and 1DNH constants of the protein UBC9.
Theoretical Study on Intermolecular Interactions and Thermodynamic Properties of Dimethylnitroamine Clusters
Authors: Ju Xue‐Hai , Xiao He‐Ming , Tan Jin‐Zhi 
Published: September 2010

AbstractAb initio SCF and Møller‐Plesset correlation correction methods in combination with counterpoise procedure for BSSE correction have been applied to the theoretical studying of dimethylnitroamine and its dimers and trimers. Three optimized stable dimers and two trimers have been obtained. The corrected binding energies of the most stable dimer and trimer were predicted to be − 24.68 kJ/mol and − 47.27 kJ/mol, respectively at the MP2/6‐31G*//F/6‐31G* level. The proportion of correlated interaction energies to their total interaction energies for all clusters was at least 29.3 percent, and the BSSE of ΔE(MP2) was at least 10.0 kJ/mol. Dispersion and/or electrostatic force were dominant in all clusters. There exist cooperative effects in both the chain and the cyclic trimers. The vibrational frequencies associated with N—O stretches or wags exhibit slight red shifts, but the modes associated with the motion of hydrogen atoms of the methyl group show somewhat blue shifts with respect to those of monomer. Thermodynamic properties of dimethylnitroamine and its clusters at different temperatures have been calculated on the basis of vibrational analyses. The changes of the Gibbs free energies for the aggregation from monomer to the most stable dimer and trimer were predicted to be 14.37 kJ/mol and 30.40 kJ/mol, respectively, at 1 atm and 298.15 K.
Theoretical Study on the NO2 + NO2− Electron Transfer Reaction
Authors: Zhou Zheng‐Yu , Gao Hong‐Wei , Xing Yu‐Mei , Guo Li , Qu Yu‐Hui 
Published: September 2010

AbstractThe NO2 + NO2− electron transfer reaction was studied with DFT‐B3LYP method at 6‐311 + G* basis set level for the eight selected structures: four species favor the structure of “head to head”. The geometry of transition state was obtained by the linear coordinate method. Three parameters, non‐adiabatic activation energy (Ead), coupling matrix element (Hif) and reorganization energy (λ) for electron transfer reaction can be calculated. According to the reorganization energy of the ET reaction, the values obtained from George‐Griffith‐Marcus (GGM) method (the contribution only from diagonal elements of force constant matrix) are larger than those obtained from Hessian matrix method (including the contribution from both diagonal and off‐diagonal elements), which suggests that the coupling interactions between different vibrational modes are important to the inner‐sphere reorganization energy for the ET reactions in gaseous phase. The value of rate constant was obtained by using above three activation parameters.
On the Criteria of Instability for Electrochemical Systems
Authors: Li Ze‐Lin , Ren Bin , Niu Zhen‐Jiang , Xiao Xiao‐Ming , Zeng Yue , Tian Zhong‐Qun 
Published: September 2010

AbstractBoth cyclic‐voltammetry‐based and impedance‐based experimental criteria that have been developed recently for the oscillatory electrochemical systems are critically appraised with two typical categories of oscillators. Consistent conclusions can be drawn by the two criteria for the category of oscillators that involve the coupling of charge transfer mainly with surface steps (e.g. ad‐ and desorption) such as in the electrooxidation of C1 organic molecules. Whereas, impedance‐based criterion is not applicable to the category of oscillators that involve the coupling of charge transfer mainly with mass transfer (e.g. diffusion and convection) such as in the Fe(CN)63‐ reduction accompanying periodic hydrogen evolution. The reason is that the negative impedance cannot include the feedback information of convection mass transfer induced by the hydrogen evolution. However, both positive and negative nonlinear feedbacks, i. e., the diffusion‐limited depletion and convection‐enhanced replenishment of the Fe(CN)63‐ surface concentration, that coexist between the bistability, i.e., Fe(CN)63‐ reduction with and without hydrogen evolution at lower and higher potential sides respectively, are all reflected in the crossed cyclic voltammogram (CCV). It can be concluded that the voltammetry‐based criterion (in time domain) is more intuitive, less time‐consuming and has a wider range of applications than the impedance‐based one (in frequency domain).
Reductive Coupling Cyclization of 1,1‐Dicyanoalkenes Promoted by Sm0/cat. HgCl2 System
Authors: Zhang Ji‐Ming , Zhang Yong‐Min 
Published: September 2010

AbstractThe intermolecular reductive coupling cyclization reactions of 1,1‐dicyanoalkenes promoted by Sm0/cat. HgCl2 were studied. A possible reaction mechanism was proposed.
An ab initio Study of Intermolecular Potential for Ne—HBr Complex
Authors: Zhang Yu , Shi Hong‐Yun 
Published: September 2010

AbstractThe potential energy surface of the ground state of the Ne—HBr complex has been calculated at several levels of theory, including the single and double excitation coupled‐cluster method with noniterative perturbation treatment of triple excitation CCSD(T). Calculations have been performed using the augmented correlation‐consistent polarized quadruple zeta basis set (aug‐cc‐pVQZ). Using the complete basis set (CBS), the global minimum with a well depth of approximate 70.516 cm−1 has been found for the linear Ne—Br—H structure (θ = 180.0°) with the distance between the Ne atom and the center of mass of the HF molecule equals (0.351 nm). In addition to the global minimum, there is a secondary minimum at Rm = 0.410 nm and θ=0° (a well depth of 57.898 cm−1). At last, the effects of the basis sets, H—Br bond length and theoretical methods on the intermolecular potential calculations of such weakly bound van der Waals complexes were discussed.
Application of Nafion/ Cobalt Hexacyanoferrate Chemically Modified Electrodes for the Determination of Electroinactive Cations by Ion Chromatography
Authors: Xu Ji‐Ming , Xian Yue‐Zhong , Shi Guo‐Yue , Li Jin‐Hua , Li‐Tong Jin 
Published: September 2010

AbstractAn amperometric detector based on the chemical modification of Nafion and cobalt (II) hexacyanoferrate (II, III) thin film (Nafion/Co‐CN‐Fe) onto a glassy carbon (GC) electrode was firstly developed for the determination of electroinactive cations (Li+, Na+, K+, Rb+, Cs+ and NH4+) in single column ion chromatography. A set of well‐defined peaks of electroinactive cation was obtained. The relative standard deviations (RSDs) of chromatographic peak height (nA) for these cations were all below 3.8%. The cations were detected conveniently in the linear concentration range of 6.0 × 10−6‐5.0 × 10−3 mol/L and their correlation coefficients were all above 0.99. The detection limits of the cations were 9.2 × 10−6 mol/L for Li+, 3.4 × 10−6 mol/L for Na+, 6.3 × 10−7 mol/L for K+, 7.8 × 10−7 mol/L for Rb+, 6.2 × 10−7 mol/L for Cs+ and 6.2 × 10−6 mol/L for NH4+, at a signal‐noise ratio of 3. The method was quick, sensitive, simple and was successfully applied to the analysis of rainwater samples. The electrode was stable for a 2 week period of operation with no evidence of chemical or mechanical deterioration.
Inorganic‐Organic Hybrid 18‐Molybdodiphosphate Nanoparticles Bulk‐modified Carbon Paste Electrode and Its Electrocatalysis
Authors: Wang Xiu‐Li , Kang Zhen‐Hui , Wang En‐Bo , Hu Chang‐Wen 
Published: September 2010

AbstractA kind of inorganic‐organic hybrid 18‐molybdodiphosphate nanoparticles ([(C4H9)4N]6P2Mo18Q62·4H2O) was firstly used as a bulk‐modifier to fabricate a three‐dimensional chemically modified carbon paste electrode (CPE) by direct mixing. The electrochemical behavior of the solid nanoparticles dispersed in the CPE in acidic aqueous solution was characterized by cyclic and square‐wave voltammetry. The hybrid 18‐molybdodiphosphate nanoparticles bulk‐modified CPE (MNP‐CPE) displayed a high electrocatalytic activity towards the reduction of nitrite, bromate and hydrogen peroxide. The remarkable advantages of the MNP‐CPE over the traditional polyoxometalates‐modified electrodes are their excellent reproducibility of surface‐renewal and high stability owing to the insolubility of the hybrid 18‐molybdodiphosphate nanoparticles.
Upper Rim Diester‐bridged Calix[4]arenes and Oligocalix [4]‐arenes: the Effects of the Length of Bridged Reagents on Their Distribution
Authors: Zeng Cheng‐Chu , Yuan Hu‐Shan , Huang Zhi‐Tang 
Published: September 2010

AbstractA series of monobridged calix[4] arenes 3a‐f, cyclic biscalix [4] arenes 4a‐f, diametrically bridged at the upper rim with saturated aliphatic diester chains, have been synthesized. The results at dilute conditions show that the percentage of yields of mono‐, bis‐ and oligo‐calix[4]arenes are related to the length of the chains. With the shortening of the chains, the percentage of monocalix[4] arenes decreased. All the calix[4] arene moieties are in a cone conformation according to the AB quartet pattern of the methylene protons between the phenolic rings in the 1H NMR spectra.
Synthesis and Crystal Structure of Bis[(2,6‐pyridinedicarboxylato) (methanol) dibenzyltin (IV)]
Authors: Yin Han‐Dong , Wang Chuan‐Hua , Wang Yong , Ma Chun‐Lin 
Published: September 2010

AbstractA novel seven‐coordinate dimer bis[(2,6‐pyridinedicarboxylato)(methanol)dibenzyltin(IV)] was synthesized by the reaction of (PhCH2)3SnCl with 2,6‐pyridine dicarboxylic acid in 1:1 molar ratio in methanol solution. The structure was characterized by elemental analysis, IR and 1H NMR spectra, and the crystal structure was determined by X‐ray single crystal diffraction analysis. The crystal belongs to monoclinic space group P21/n, a =0.96250(19) nm, b = 1.0947(2) nm, c = 1.9965(4) nm, β = 92.31(3)°, Z = 2, V = 2.1019(7) nm3, Dc = 1.574 g/cm3, μ = 1.248 mm−1, F(000)=1000, R1 = 0.0675, wR2 = 0.0836. In the crystals of the complex, each tin atom is seven‐coordinated in a distorted bipyramidal structure.
Ytterbium Coordination Polymer with Four Different Coordination Numbers: The First Structural Characterization of Lanthanide Phthalate Complex
Authors: Wan Yong‐Hong , Jin Lin‐Pei , Wang Ke‐Zhi 
Published: September 2010

AbstractThe novel ytterbium coordination polymer is a two‐dimensional framework in which the central metal ions have four different coordination numbers and form four kinds of coordination polyhedra. The four kinds of coordination polyhedra connect into infinite chains by sharing oxygen atoms.
Thermodynamic Properties of Transfer for Tetraphenylarsonium Tetraphylborate from Water to n‐Alkanols
Authors: Zou Li‐Zhuang , Wang Xiao‐Ling , Zhu Shu‐Quan , Wei Lu‐Bin , Lu Yao , Wang Jin‐Ben 
Published: September 2010

AbstractSolubilities of tetraphenylarsonium tetraphenylborate (Ph4AsB‐Ph4) in water, methanol, ethanol, 1‐propanol, 1‐butanol, 1‐pentanol, 1‐hexanol and 1‐octanol at T = 293.2, 298.2, 303.2 and 308.2 K have been determined by spectrophotometry. The standard transfer Gibbs energy (Δtr‐G0w‐s) and entropy (Δtr‐G0w‐s) of Ph4AsBPh4 from water to the n‐alkanols at temerature from 293.2 K to 308.2 K have been obtained. Furthermore, the contribution of microscopic interaction to the standard Gibbs energy of transfer for Ph4AsBPh4 was calculated and discussed. The results show that the effect of hydrophobic interaction of Ph4AsBPh4 on its transfer process is the most important factor. According to the thermodynamical principle, the transfer process of Ph4AsBPh4 from water to the n‐alkanols is the entropy dominated.
Theoretical Study on Reactivity of Electron Transfer in Model‐System of Oxidation of α ‐Amino Carbon‐centered Radical by O2
Authors: Li Xiang‐Yuan , Liu Ji‐Feng , Yu Hua‐Bin 
Published: September 2010

AbstractElectron transfer reaction between a simplified model molecule of α‐amino carbon‐centered radical and O2 has been studied with ab initio calculations at the MP2/6‐31 ++ G**//UHF/6‐31 ++ G** level. The reactant complex and the ion pair complex have been optimized and employed to perform calculations of the reaction heat and the reorganization energy. Solvent effects have been considered by applying the conductor‐like screening model. Theoretical results show that the highly endothermic charge separation process, in which one electron transfers from the α‐amino carbon‐centered radical to O2, so as to form an ion pair complex, is difficult to occur in gas‐phase. By applying an external electronic field to prepare the charge‐localized molecular orbitals, the charge‐separated state has been obtained using the initial‐guess‐induced self‐consistent field technique. The theoretical investigations indicate that the solvent effect in the process of the oxidation of α‐amino carbon‐centered radical by O2 is remarkable. From the rate constant estimation, it can be predicted that the oxidation of the model donor molecule by O2 can proceed, but not very fast. A peroxyl radical compound has been found to be a competitive intermediate in the oxidation process.
Crystal Structure and Magnetic Property of Heteronuclear Copper‐Lanthanum Carboxylate Complex
Authors: Wu Bin , Lu Wei‐Min , Zheng Xiao‐Ming 
Published: September 2010

AbstractThe title complex, [CuLaL5 (phen) (C2H5OH)]2 (where L = α‐methylacrylato; phen = 1, 10‐phenanthroline), has been prepared and its structure has been determined by X‐ray diffraction analysis. The complex crystallizes in triclinic system with space group P 1. Crystal data: a = 1.2725 (3) nm, b = 1.4421 (4) nm, c = 1.2109 (2) nm, α = 109.48 (2)°, β = 115.26 (2)°, γ = 66.42 (2)°. The complex is a discrete tetranuclear CuLaLaCu molecule bridged by α‐methylacrylato groups. Magnetic property of the complex was also measured and discussed.
Synthesis and Structural Characterization of Two Molybdenumphosphate Cluster Compounds: (C14N14H63) Na (H2Mo6P4O31)2 · 8H2O and (C14N14H63) Na (H2Mo6P4O31)2 · 5H2O
Authors: Wen Fu‐Shan , Chen Wei , Shi Zhan , Li Guang‐Hua , Yu Zhen‐Tao , Chen Jie‐Sheng 
Published: September 2010

Abstract(C14N14H63) Na (H2Mo6P4O31)2 · 8H2O (1) with amine‐separated sodium molybdenumphosphate clusters and (C14N14H63) Na (H2Mo6P4O31)2 · 5H2O (2) with H‐bonded duster layers were synthesized from hydrothermal systems. Compound 1 crystallizes in the triclinic space group P · with a = 1.27445 (2) nm, b = 1.37183 (3) nm, c = 1.41515 (3) nm, α = 100.497 (1)°, β = 109.064 (1)° and γ = 115.498 (1)°. Whereas compound 2 has a monoclinic space group P21/n with a = 1.3418 (5) nm, b = 2.7787 (12) nm, c = 2.0314 (10) nm and β = 96.571 (14)°. There exist protonated ethylenediamine cations and H2O molecules between adjacent dusters, connecting the dusters through H‐bonds.
Pendant‐armed Unsymmetrical Aza‐macrocycles: Syntheses, Coordination Behavior and Crystal Structure of a Dinuclear Cadmium Complex
Authors: Tao Jing‐Chao , Liao Xin‐Cheng , Wang Xing‐Wang , Du Chen‐Xia 
Published: September 2010

AbstractTwo unsymmetrical tetradentate aza‐macrocycles with side arms attached to the Nsp3 atoms, L1 and L2, as well as their complexes with different metal cations were synthesized and characterized by EA, UV, IR, 1H NMR and MS spectra. Both the two ligands can efficiently transport alkali and transition metal cations across an organic membrane with high selectivity ratio. The structure of a dinuclear Cd (II) complex [L1] · (Cd‐Cl2)2 was elucidated by X‐ray crystallography and was solved by the heavy‐atom method to a final R value of 0.029 for 3084 reflections with |F| > 3σ (I). In the exo‐structure of the dinuclear complex each cadmium atom is five‐coordinated, bonding to three N atoms and two chlorine atoms.
A New Fluorimetric Reagent for Determination of Trace Amounts of Europium
Authors: Lin Peng , Zheng Hong , Zhu Qing‐Zhi , Xu Jin‐Gou 
Published: September 2010

AbstractIn this paper, a new ligand, 2, 9‐bis [N, N‐bis (carboxymethyl) ‐aminomethyl] −1, 10‐phenanthroline, was synthesized and used to establish a novel fluorimetric method for the determination of trace amounts of europium. The fluorescence intensity was a linear function of the concentration of europium in the range,of 4.0 × 10−9—1.0 × 10−6 mol/L. The detection limit was 1.0 × 10−9 mol/L. The standard addition method was used to determine the europium in a synthetic rare‐earth sample and high purity Y2O3 matrix with satisfactory results.
Single‐Molecular Imaging of Anticoagulation Factor I from Snake Venom by Atomic Force Microscopy
Authors: Xu Xiao‐Long , Zhou Yun‐Shen , Liu Qing‐Liang , Hou Jian‐Guo , Yang Jing‐Long , Xie Yong‐Shu 
Published: September 2010

AbstractAnticoagulation factor I (ACF I) from the venom of Agkistrodon acutus is a binding protein to activated coagulation factor X (FXa) and possesses marked anticoagulant activity. Single ACF I molecule has been successfully imaged in air by tapping mode atomic force microscopy (AFM) with high‐resolution using glutaraldehyde as a coupling agent. The physical adsorption and covalent binding of ACF I onto the mica show very different surface topographies. The former exhibits the characteristic strand‐like structure with much less reproducibility, the latter displays a elliptic granular structure with better reproducibility, which suggests that the stability of ACF I molecules on the mica is enhanced by covalent bonding in the presence of glutaraldehyde. A small‐scale AFM amplitude‐mode image clearly shows that the covalently bonded ACF I molecule by glutaraldehyde has olive shape structure with an average size of 7.4 nm × 3.6 nm × 3.1 nm, which is very similar to the size determined from the crystal structure of ACF I.
Study on the Phase Diagram of CsCl‐CeCl3‐HCl (11%)‐H2O System and the Properties of the Compounds
Authors: Wang Hui , Duan Jin‐Xia , Ran Xin‐Quan , Gao Shi‐Yang 
Published: September 2010

AbstractThe equilibrium solubility of CsCl‐CeCl3‐HCl (11%)‐H2O quaternary system at 25 °C has been determined by the physic‐chemical analysis method, and the phase diagram was plotted. Two new double salts 3CsCl · CeCl3 · 3H2O and CsCl · CeCl3 · 4H2O obtained from the complicated system were identified and characterized by XRD, TG‐DTA, DSC, UV and fluorescence spectroscopy. Studies on the fluorescence excitation and emission show that 3CsCl · CeCl3 · 3H2O and CsCl · CeCl3 · 4H2O have upconversion luminescence of infrared‐visible range, and the upconversion emission intensity increases with the increase of ratio of CeCl3 in CsCl.
Synthesis of Eu (III) and Tb (III) Complexes with Two New Amide Type Podands and Their Luminescence Properties
Authors: Zhang Jian , Tang Yu , Fan Jun , Cai Zheng‐Hong , Liu Wei‐Sheng , Tan Min‐Yu 
Published: September 2010

AbstractTwo new amide type podands L1 and L2 (L1 = 1, 1, 1‐tris {[(2‐benzylaminoformyl) phenoxyl] methyl} propane, L2 = 1, 3, 5‐trimethyl‐2, 4, 6‐tris {[(2‐benzylaminoformyl) phenoxyl] methyl} benzene) and their europium and terbium nitrates complexes were synthesized. The luminescence properties of these complexes were also studied.
Development of Highly Effective Nanoparticle Spinel Catalysts for Aerobic Oxidation of Benzylic Alcohols
Authors: Ji Hong‐Bing , Wang Le‐Fu 
Published: September 2010

AbstractSpinel catalyst MnFe1.8Cu0.15Ru0.05O4 with particle size of about 42 nm is an effective heterogeneous catalyst for the oxidation of benzylic alcohols. The substitution of Fe for Cu improves its catalytic activity. Based on the characterization of BET, XPS and EXAFS, two factors influencing the structure and texture of the catalyst caused by the substitution of Cu for Fe may be assumed: physical factor responsible for the increasing of surface area; chemical factor responsible for the transformation of RuO bonds to RuO bonds. β‐Elimination is considered to be an important step in the reaction.
Ab initio Study on Enantioselective Reduction of Ketones Catalyzed by Thiazolidino [3, 4‐c ] oxazaborolidines
Authors: Li Ming , Xie Ru‐Gang , Han An‐Min 
Published: September 2010

AbstractThe ab initio molecular orbital method is employed to study the enantioselective reduction of acetophenone with borane catalyzed by thiazolidino [3, 4‐c] oxazaborolidine. Computation resuit shows that the controlling step for the reduction is the decomposition of the catalyst‐alkoxyborane adduct and the reduction leads to S‐alcohols. The transition state of the hydride transfer from the borane moiety to the carbonyl carbon of acetophenone is a twisted chair structure with a B (2)—N (3)—BBH3—HBH3—CCO—OCO 6‐membered ring.
One‐Dimensional Network Constructed by Salicylate and Phenanthroline Ligands with Copper (II)
Authors: Zhu Lag‐Guan , Cai Guo‐Qiang 
Published: September 2010

AbstractA novel complex, [Cu2 (phen) (sal) (Hsal)2]n (1), was synthesized and structurally characterized. The base dimeric units are hold by sal ligands and extended into 1‐D network. The carboxylate groups of salicylates coordinate to the central ion in three different coordination modes: chelating, bridging and bridging‐chelating. In the case of bridging‐chelating of the carboxylate group of the salicylate, all three oxygen atoms of salicylate are bidentately coordinated to copper ion, namely, μ4‐η3 binding mode.