bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silica Immobilized Ruthenium Catalyst for Formic Acid Synthesis from Supercritical Carbon Dioxide Hydrogenation II: Effect of Reaction Conditions on the Catalyst Performance
Authors: Ying‐Min Yu , Yi‐Ping Zhang , Jin‐Hua Fei , Xiao‐Ming Zheng 
Published: October 2005

AbstractThe synthesis of formic acid from carbon dioxide and hydrogen using a silica immobilized ruthenium catalyst as precursor has been studied in different reaction conditions. The results revealed that the TOF (turn over frequency) of HCOOH achieved 1481.5 h‐1 on immobilized ruthenium catalyst near the critical pressure point of CO2 with H2 pressure of 4.0 MPa, reaction temperature of 80 °C and PPh3/Ru molar ratio of 6:1. The reaction activity of immobilized catalyst was higher than that of homogeneous catalyst, and the immobilized catalyst also offered the practical advantages such as easy separation and reuse.
Preparation of Nanosized CoHCF Modified Electrode and Its Application to Electroanalysis of Hemoglobin
Authors: Mei‐Chuan Liu , Ping Li , Li Zhang , Yue‐Zhong Xian , Hong‐Chun Ding , Cheng‐Lin Zhang , Fen‐Fen Zhang , Li‐Tong Jin 
Published: October 2005

AbstractA cobalt hexacyanoferrate (CoHCF) nanoparticle (size ca. 60 nm) chemically modified electrode (CME) was fabricated and the electrochemical behavior of hemoglobin (Hb) at this nanosized CoHCF CME was studied. In comparison with a bare glassy carbon electrode (GCE) and a general CoHCF CME electrodeposited in a traditional manner, the present nanosized CoHCF CME performed efficiently electrocatalytic reduction for Hb with relatively high sensitivity, stability, and longlife. Combined with liquid chromatography (LC), the nanosized CoHCF CME was used as the electrochemical detector of Hb in the established flow injection analysis‐electrochemical determination (FIA‐ECD) system. The peak current was a linear function of concentrations in the range from 2.5×10‐8 to 5.0×10‐6 mol/L for Hb, with detection limit of 1.4×10‐8 mol/L. The FIA‐ECD system has been successfully applied to assess the Hb content of clinic blood samples with advantages of sensitiveness, speediness, easy control and small sample‐consumption.
Characterization and Activity of CH3OOH and CH3CH2OOH Study on a Photoelectron Spectroscopy
Authors: Yi‐Min Li , Qiao Sun , Hai‐Yang Li , Mao‐Fa Ge , Dian‐Xun Wang 
Published: October 2005

AbstractThe ionization energies of MHP (CH3OOH) and EHP (CH3CH2OOH) have been determined by HeI photoelectron spectroscopy (PES) measurement and both Gaussian‐2 (G2) calculation and Hartree‐Fock (HF) method on the basis of Koopmans theorem at 6‐311+G* basis set level for the first time. The assignment and characterization of PE spectra of MHP and EHP were also supported by the G2 and HF calculations. The first ionization energies of MHP and EHP are 9.87 and 9.65 eV, respectively. Higher solubility of EHP in the atmosphere was attributed to their lower ionization energy values.
Preparation of Polystyrene/Fe3O4 Nanoparticles in Triton X‐100/ Sodium Dodecyl Benzenesulfonate Mixed Surfactant System
Authors: Gen‐Ping Song , Jie Bo , Rong Guo 
Published: October 2005

AbstractThe composite nanoparticles of polystyrene/Fe3O4 with a shell‐core structure were prepared in the mixed system of Triton X‐100 and SDBS. The shell of the composite nanoparticles was formed by polystyrene and the core by Fe3O4 nanoparticles. The diameter of Fe3O4 nanoparticles is about 10 nm and that of the composite nanoparticles 25‐35 nm. The XRD spectra and FTIR spectra show that the enwrapping of polystyrene with Fe3O4 nanoparticles was successful.
Synthesis and Crystal Structure of a 2D Honeycomb‐like Polymeric Cluster (Et4N)3{[MoS4Cu2(μ‐CN)]2(μ′‐CN)}·2MeCN
Authors: Shan‐Bao Qiao , Chang‐Mei Jiao , Wen‐Hua Zhang , Zhi‐Gang Ren , Yong Zhang , Jian‐Ping Lang 
Published: October 2005

AbstractReaction of a preformed cluster (Et4N)2[MoS4(CuCN)2]·H2O (1) with acetic acid in MeCN gave rise to an interesting 2D polymeric cluster (Et4N)3{[MoS4Cu2(μ‐CN)]2(μ′‐CN)}·2MeCN (2). Compound 2 was characterized by elemental analysis, IR spectrum, and single crystal X‐ray crystallography. In the structure of 2, the cluster core MoS4Cu2 of the cluster precursor 1 is retained and serves as a 3‐connecting node to link equivalent nodes via single cyanide bridges, forming an anionic 2D (6,3) (honeycomb‐like) network. The acetic acid induced aggregation of supramolecular compound 2 from the cluster precursor 1 suggests that this simple synthetic strategy be likely applicable to many related systems.
Structural Characterization and Relaxivity Study of a New Paramagnetic Mn(II) Complex of DTPA‐BpABA
Authors: Ying‐Chun Liu , Jing Zhang , Quan Luo , Shu‐Lan Ma , Miao‐Qiong Xu , Wen‐Xiang Zhu 
Published: October 2005

AbstractX‐ray single crystal analysis of a new paramagnetic manganese(II) complex with DTPA‐BpABA (a DTPA‐ bisamide derivative), Mn(DTPA‐BpABA)·4H2O, shows that four oxygen atoms and three nitrogen atoms from the ligand coordinate to Mn(II) cation, forming a seven‐coordinate distorted pentagonal bipyramid polyhedron. In the crystal, the carboxyl groups and the nitrogen atoms extensively form hydrogen bonds with the lattice water molecules, building a 3D‐network. The relaxometric study indicates that the R1 value of the paramagnetic manganese(II) complex is 5.12 mmol·L·s‐1. The higher R1 value means that this complex may find an application in magnetic resonance imaging (MRI) technique.
Transformation from n‐Diamond to sp3‐Banding Carbon
Authors: Bin Wen , Ting‐Ju Li , Chuang Dong , Xing‐Guo Zhang , Shan Yao , Zhi‐Qiang Cao , De‐He Wang , Shou‐Hua Ji , Jun‐Ze Jin 
Published: October 2005

AbstractWith admixture of n‐diamond and diamond‐like carbon powders (DLC) as carbon source, transparent wafers have been synthesized by hydrothermal process at 100 °C and atmosphere pressure. Scanning electron microscopy, X‐ray diffraction, Raman spectroscopy, transmission electron microscopy, electron‐probe microanalysis andFourier‐transform infrared spectrometer were used to analyze those transparent wafers. These results indicated that the transparent wafers were amorphous sp3‐banding carbon wafer, and that the wafers were not aggregate of DLC from the carbon source but a new kind of reaction product by hydrothermal treatment.
Syntheses and Characterization of Several Copper‐halo Clusters
Authors: Jie‐Hui Yu , Ji‐Qing Xu , Yu‐Jiang Song , Hai‐Ying Bie , Jing Lu , Tie‐Gang Wang 
Published: October 2005

AbstractThe hydrothermal reaction of CuBr2 and CuBr with phen·H2O (phen=1,10‐phenanthroline) in a molar ratio of 1:1:1.5 gave birth to the first copper‐halo cationic cluster [Cu2IICu2IBr4(phen)4]2+ (1) with tetranuclear anionic cluster [Cu4Br6]2‐. Changing the precursors or their molar ratios, two mononuclear complexes [Cu(phen)2Br]Br·H2O (2) and [Ni(phen)3][CuCl2]2 (3) as well as two unusual copper‐halo chains found in polymers [Cu2Br2(phen)]∞ (4) and [CuIICu3IBr2I3(phen)2]∞ (5) were obtained. The (Cu2Br2)∞chain of 4 looks like a linear array of hexagons based on fused Cu3Br3 units, and the linear (Cu3I3Br‐)N,N′chain of 5 is an alternate combination of the rhombic Cu2I2 cores and the Cu4I4Br22‐ units. In addition, the hydrothermal reaction of CuBr2 with NA(NA=nicotinic acid) or INA (INA=isonicotinic acid) resulted in the syntheses of two compounds [CuBr(NA)] (6) and [CuBr(INA)]∞ (7) containing staircase chain. Among them the third‐order non‐linear optical properties of 2, 5, 6 and 7 were investigated and all exhibit the reverse saturable absorption (α2>0) and self‐defocusing performance(n2<0).
Fluorescence Determination of Artemisinin Using Tyrosinase as Catalyst and Pyronine B as Monitor
Authors: Li‐Hua Chen , Hong Yin , Zhao‐Xia Yang , Ke‐Mei Zhang , Liu‐Zhan Liu , Han‐Xi Shen 
Published: October 2005

AbstractFluorescence decrease ratio (F0/F) was applied to determination of artemisinin (qinghaosu, QHS) based on the catalytic effect of tyrosinase using tetraethyldiaminoxanthenyl chloride (pyronine B, PB) as monitor. A catalyst used commonly in the decomposition of QHS, tyrosinase, exhibited higher binding activity than hemin, which was expressed as Michaelis‐Menten parameters, km, vmax, and kcat respectively. Interaction of QHS with tyrosinase was inhibited in the presence of deactivating agents at high temperature whereas enhanced by ethanol. Under optimal conditions, a concentration of 1.4×10‐7‐8.4×10‐7 mol·L‐1of QHS could be determined on the basis of fluorescence decrease ratio of PB, with a detection limit 3σ of 2.6×10‐9 mol·L‐1. The proposed method was applied to detection of the concentration of QHS in the media of plasma and urine.
Effect of Damping Mechanisms on Mass Calibration Equation for MALDI/FTMS
Authors: Yue Su , Hao‐Yang Wang , Yin‐Long Guo , Bing‐Ren Xiang , Deng‐Kui An 
Published: October 2005

AbstractCollisional damping affects the relationship between ion mass and effective cyclotron frequency in Fourier transform mass spectrometry. The exact mass calibration equation magnified image was therefore derived from the characteristic equation of system model, force $ = m{{{\rm d}v} \over {{\rm d}t}} = qE-qv \times B_{0} - \xi v$ (ξv, a frictional damping force), in which k is amended by the shift of observed frequency of matrix ion or other known ion in external calibration. The mass obtained by the amended calibration equation is therefore immune to collisional damping and space‐charge effects on mass accuracy. The relative errors of ion mass measured were all less than 2×10‐6.
Odorless and Practical Thioacetalization Reagent: Methyl 2‐(1,3‐Dithian‐2‐ylidene)‐3‐oxobutanoate
Authors: Ran Sun , Qun Liu , Hai‐Feng Yu , Yu‐Long Zhao , Jun Liu , Yan Ouyang , De‐Wen Dong 
Published: October 2005

Abstractα‐Oxo ketene dithioacetals, methyl 2‐(1,3‐dithian/dithiolan‐2‐ylidene)‐3‐oxobutanoate (2a/2b) prepared in nearly quantitative yields simply from methyl acetylacetate, carbon disulfide and 1,3‐dibromopropane/1,2‐dibro‐ moethane in the presence of potassium carbonate, were investigated in the thioacetalization with various carbonyl compounds 3. It has been demonstrated that methyl 2‐(1,3‐dithian‐2‐ylidene)‐3‐oxobutanoate (2a) could act as a nonthiolic, odorless and practical thioacetalization reagent. A range of aldehydes and ketones 3 were converted into the corresponding dithioacetals 4 in high yields (up to 91%) in the presence of 2a. Moreover, 2a showed high chemoselectivity between aldehyde and ketone in thioacetalization.
Synthesis and Structural Characterization of Three Novel Macrocyclic Coordination Complexes Formed by Self‐assembly of Bridged Bi‐ or Tetrapyridine with Transition Metal Salts
Authors: Li‐Cheng Song , Guo‐Xia Jin , Wen‐Xiong Zhang , Qing‐Mei Hu 
Published: October 2005

AbstractSelf‐assembly of a ferrocenyl‐bridged bipyridine ligand bpef [bpef=1,1′‐bis(trans‐2‐pyrid‐4′‐ylethenyl)ferrocene] with silver triflate in CH2Cl2/MeOH or mercuric diiodide in MeCN/CH2Cl2 gave the corresponding macrocyclic coordination complexes [bpef]2[AgSO3CF3]2 (1) and [bpef]2[Hg3I6] (2) in 93% and 89% yields, respectively, whereas the pentaerythritolyl‐bridged tetrapyridine ligand ptpc [ptpc=pentaerythritol tetrakis‐(4‐pyridinecarboxylate)] reacted with cobalt thiocyanate via self‐assembly to afford the macrocyclic coordination polymer [Co(NCS)2(ptpc)]n (3) in 90% yield. The X‐ray diffraction analyses for 1‐3 confirmed their novel macrocyclic structures and revealed that (i) the two silver atoms in complex 1 have an essentially linear geometry with N‐Ag‐N bond angle of 175.7°and 172.9° , (ii) the geometry of the middle mercury atom in complex 2 is square‐planar, while the other two mercury atoms in the other two complexes are tetrahedral, and (iii) all the cobalt atoms in complex 3 adopt an octahedral geometry. In addition, the synthetic procedure for the known tetrapyridine ligand ptpc has been improved.
Mercurous Chloride Catalyzed Mannich Condensation of Terminal Alkynes with Secondary Amines and Aldehydes
Authors: Pin‐Hua Li , Lei Wang 
Published: October 2005

AbstractMercurous chloride catalyzed Mannich condensation of terminal alkynes with secondary amines and aldehydes has been developed. The reaction generated β‐aminoalkynes in good yields.
Copolymerization of Ethylene/1‐hexene and Polymerization of Propylene with Cp‐indenyl Zirconium Complexes
Authors: Yong Zhang , Xiao‐Xia Yang , Yi‐Hua Yu , Yan‐Long Qian , Ji‐Ling Huang 
Published: October 2005

AbstractComplexes (R1Cp)(R2Ind)ZrCl2, the catalysts previously reported active for ethylene polymerization showed high activity in ethylene/1‐hexene copolymerization and propylene polymerization in the presence of MAO. The content of 1‐hexene in copolymers ranged from 1.2% to 3.2%. In propylene polymerization the complex 1 showed the highest activity, up to 1.2×106 g of polypropylene per mol of catalyst per hour. Based on the analysis of NMR spectral data, the relationships between complex structures and polymerization results were explored.
Role of Carborane in Polymerization and Insertion Reactions
Authors: Zuo‐Wei Xie 
Published: October 2005

AbstractLigand modifications have played a crucial role in developing new catalyst precursors. A novel class of “constrained‐geometry” ligands bearing a carboanion functionality has been developed by linking o‐carboranyl and π‐ligand together. They offer group 4 metal complexes higher activity in olefin polymerization compared to those with appended heteroatom systems. The results show that the [{η5: σ‐Me2A(C5H4)(C2B10H10)}M] moiety remains intact in olefin polymerization and insertion reactions of various unsaturated molecules, and the electron‐deficient yet sterically hindered icosahedral carborane does play an important role in the reactions. This article provides an overview of our recent work on this subject.
Synthesis of Fullerene‐end Functionalized Poly(methyl methacrylate) via Reverse Atom Transfer Radical Polymerization
Authors: Chong‐Dong Guo , Wen‐Rui Teng , Hui‐Xia Wu , Jian‐Zhong Shen , Xiao‐Min Deng , Rui‐Fang Cai 
Published: October 2005

AbstractThe use of the reverse atom transfer radical polymerization (RATRP) to end‐functionalize poly(methyl methacrylate) (PMMA) with fullerenes, e.g. C60 and C70 was described in this paper. The Cl‐terminated PMMA was prepared via RATRP with designed molecular weight and narrow molecular weight distributions, and then directly used to react with fullerenes to produce C60(C70) terminated PMMA polymers in the presence of CuBr/Cu/bipy or FeCl2/bipy catalysts. The resultant polymers exhibit good solubility in some common organic solvents, e.g. THF, CHCl3 and toluene, and were well structurally characterized by a variety of physical techniques.
Study on the Three‐dimensional Quantitative Structure‐activity Relationship of Pyridazinonyl‐substituted 1,3,4‐Thiadiazoles
Authors: Xia‐Juan Zou , Lu‐Hua Lai , Gui‐Yu Jin 
Published: October 2005

AbstractThe three‐dimensional quantitative structure‐activity relationships of a series of 5‐[1‐aryl‐1,4‐dihydro‐6‐methylpyridazin‐4‐one‐3‐yl]‐2‐arylamino‐1,3,4‐thiadiazoles, related to the fungicidal activity, were studied using the comparative molecular field analysis (CoMFA). The results show that the contributions of steric and electrostatic fields to the activity are 0.505 and 0.495, respectively. The cross‐validated q2 and the correlation coefficient r2 for the model established by the study are 0.769 and 0.938, respectively, with the F value of 60.996, and the standard deviation s of 0.074. These values indicate that the model is significant and has good predictability. The analysis results are in good agreement well with the study of 2D‐QSAR, and offered important structural insights into designing highly active compounds prior to synthesis.
Organic‐inorganic Hybrid Materials Based on Molybdophosphate and Organic Polyammonium
Authors: Su‐Rong Jin , Lian‐Meng Zhang , Shi‐Zhong Liu , Li‐Feng Yao , Xue‐Lei Hu , Wei‐Feng Zhao 
Published: October 2005

AbstractA new organic‐inorganic hybrid compound (dienH3)2(P2Mo5O23) (1) [dien=NH(CHCH2NH2)2] has been hydrothermally synthesized and characterized by elemental analyses, IR spectrum, thermogravimetric analysis, and the single crystal X‐ray diffraction technique. Compound 1 crystallizes in the triclinic system with space group ${P}{\bar 1}$ and a=0.9790(2) nm, b=0.9922(2) nm, c=1.4644(3) nm, α=95.510(10)°, β=98.860(10)°, γ=95.700(10)°, V=1.3895(5) nm3, z=2, r=0.0465. The results show that the compound consists of dienH33+ and P2Mo5O236‐, and the heteropoly anion P2Mo5O236‐ is connected to a 1‐D chain structure with the protonated dien by hydrogen bonds.
Synthesis and Structures of Lanthanide Complexes of N‐p‐Tolylsulfonylglycinate and 1,10‐Phenanthroline
Authors: Zhang Man‐Bo , Hu Rui‐Xiang , Liang Fu‐Pei , Ma Lu‐Fang , Zhou Zhong‐Yuan 
Published: October 2005

AbstractThree new lanthanide complexes with the formulae [Eu2(TsGly) 6(phen) 2(H2O) 2] (1), [Ln(TsGly) 2(phen) 2(H2O) 2]Cl·2H2O [Ln=Er (2a) and Yb (2b), TsGlyN‐p‐tolylsulfonylglycinate, phen1,10‐phenanthroline] were synthesized. Crystallographic data for 1: monoclinic, P21/n, a=1.29791(16) nm, b&&equals;1.9034(2) nm, c=1.7596(2) nm, β=93.410(3) °, V=4.3394(9) nm3, Z=4, R1=0.0326, wR2=0.0771; and for 2b: triclinic, P1, a=1.2674(2) nm, b=1.4405(2) nm, c=1.4809(3) nm, α=113.256(3) °, β=108.253(3) °, γ=94.739(3) °, V=2.2922(7) nm3, Z2,R1=0.0292, w R2=0.0669. X‐ray diffractional analysis reveals that compound 1 adopts dinuclear structure with fourfold bridging TsGly ligands between the Eu(III) centers, while compound 2b features an unusual mononuclear structure.
Study on Binding Reaction between Flucytosine and Bovine Serum Albumin
Authors: Yan Cheng‐Nong , Zhang Hua‐Xin , Mei Ping , Liu Yi 
Published: October 2005

Abstract The binding of flucytosine to bovine serum albumin (BSA) was studied by means of fluorescence and absorption spectra under the conditions of simulant clay physiology. It showed a powerful ability to quench the fluorescence launching from BSA. After analyzing the fluorescence quenching data by Stern‐Volmer equation and Lineweaver‐Burk double‐reciprocal equation, it was found that they matched the latter better and so they belonged to static quenching. The binding constant was calculated to be 5.710×103 L·mol‐1 at 297 K. The binding locality was a distance 2.49 nm away from tryptophan residue‐212 based on Förster's non‐radiation energy transfer mechanism. The binding power is mainly the hydrogen bond and van der Waals force according to the thermodynamic parameters. The information of BSA conformation was acquired by synchronous fluorescence spectrum and three‐dimensional fluorescence spectrum.
Effect of Na+, K+ and Ca2+ Ions on Physico‐chemical Properties of Thymine, Cytosine, Thymidine and Cytidine in Aqueous Urea Solution
Authors: Pandey Jata Dhari , Haroon Shahla , Chhabra Jyotsna , Dey Ranjan , Misra Krishna 
Published: October 2005

AbstractExperimental determination of density, ultrasonic velocity and viscosity of two pyrimidine bases thymine and cytosine along with their respective nucleosides, thymidine and cytidine has been carried out in aqueous urea solutions in the presence of different concentrations of three salts, viz. NaCl, KCl and CaCl2. The experimental data have been used for the computation of various thermodynamic parameters, viz. apparent molar volume, apparent molar compressibility, coefficients A and B of the Jones‐Dole equation, internal pressure, acoustic impedance, etc. Structural studies of solutions under investigation have also been carried out by ultraviolet spectroscopy, and an attempt has been made to collaborate the findings of ultraviolet spectroscopy with results obtained thermodynamically.
Synthesis and Anticancer Activity of 2,3,4‐Trimethoxyacetophenoxime Ester Containing Benzothiazole Moiety
Authors: Song Bao‐An , Liu Xin‐Hua , Yang Song , Hu De‐Yu , Jin Lin‐Hong , Zhang Hua 
Published: October 2005

AbstractA series of 2,3,4‐trimethoxyacetophenoxime esters containing benzothiazole moiety were synthesized by the reaction of oxime with acyl chloride in alkaline medium. Their structures were established by elemental analysis, IR, and 1H NMR spectra. The bioassay tests showed that these title compounds exhibit moderate anticancer activity in vitro by MTT method and compounds 6c and 6d could inhibit ERK phosphorylation in NIH 3T3 cell induced by PDGF.
Photochemical Degradation Study of Polyurethanes as Relic Protection Materials by FTIR‐ATR
Authors: Wang Li‐Qin , Liang Guo‐Zheng , Dang Gao‐Chao , Wang Fang , Fan Xiao‐Pan , Fu Wen‐Bin 
Published: October 2005

AbstractPolyurethanes are one kind of relic protection materials commonly used. During artificial photo‐ageing, three polyurethanes, HDI‐based polyurethane, MDI‐based polyurethane and TDI‐based polyurethane, have been considered to undergo UV radiation. Photochemical degradation of the polyurethanes has been monitored by means of Fourier transform infrared spectroscopy with attenuated total reflection accessory (FTIR‐ATR). It was proved that the mechanism of the photochemical degradation of polyurethanes might be the scissions of carbamate (urethane) groups and the re‐reactions of radical groups formed in the scission reactions. From the experiment results HDI‐based polyurethane, an aliphatic diisocyanate, could be considered to be more suitably used as relic protection materials among these three polyurethanes for its ageing products with less color.
New Methods and Synthetic Applications of Asymmetric Nitrogen Transfer
Authors: Armstrong Alan , Edmonds Ian , Cooke Richard S. , Shanahan Stephen E. , Knight Jamie D. , Cumming Graham R. 
Published: October 2005

AbstractStructure/reactivity relationships of N‐alkoxycarbonyl‐ and N‐carboxamidooxaziridines are explored, and conditions are discovered for the efficient amination of sulfides and primary amines. Reactions of these oxaziridines with alkenes are also examined, and lead to interesting new heteroatom transfer reaction products. Finally, the aminative rearrangement of 2‐alkoxydihydropyrans leads to a useful stereocontrolled synthesis of pyrrolidines which can undergo synthetic manipulations to give [2.2.1]‐ and [3.2.1]‐azabicycles.