bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Metal Complexes of Heterocyclic Phosphines. Synthesis and Steric Structure
Authors: KARASIK A. A. , NIKONOV G. N.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Supramolecular Architectures from Phthalocyanine Building Blocks
Authors: VAN NOSTRUM C. F. , NOLTE R. J. M.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Metallacarboranes of the C2B4‐Cage Systems
Authors: HOSMANE N. S. , MAGUIRE J. A.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Applied Photochemistry for Free Radical Organic Synthesis by Means of Distannane Reagents.
Authors: NEUMANN W. P. , HARENDZA M. , JUNGGEBAUER J. , LESSMANN K. , TEWS H.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Recent Progress in Asymmetric Synthesis
Authors: OPPOLZER W.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Protection of Multiple C‐C and Single C‐H Bonds in Organic Synthesis
Authors: SVOBODA J. , PALECEK J.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Hydrodechlorination of Chloroaromatics on Hydrorefining Catalysts
Authors: NOVAK M.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: The Diagnosis of Concerted Organic Mechanisms
Authors: WILLIAMS A.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Regio‐ and Chemoselective Synthesis of Halohydrins by Cleavage of Oxiranes with Metal Halides
Authors: BONINI C. , RIGHI G.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Three Component Synthesis of Prostanoids. The Usage of Aldehydes, Nitroolefins and Derivatives of Carboxylic Acids in Tandem Additions
Authors: LHOTAK P. , PALECEK J.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Isothiocyanates and Cyclic Thiocarbamates of α,α′‐ Trehalose, Sucrose, and Cyclomaltooligosaccharides.
Authors: GARCIA FERNANDEZ J. M. , ORTIZ MELLET C. , JIMENEZ BLANCO J. L. , FUENTES MOTA J. , GADELLE A. , COSTE‐SARGUET A. , DEFAYE J.
Published: September 2010

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Kinetic behaviour of aluminum naphthenate/benzene system in process of gelation and degradation
Authors: Wang Guang‐Xin , Cheng Zhong‐Qi , Su Pei‐Shan , Guo Xiao‐Dong
Published: September 2010

The kinetic behaviour of aluminum naphthenate/benzene system in the process of gelation and degradation was systematically studied. The results obtained from the kinetic experiments indicated that the gelation stage was in accordance with a kinetic model of an auto‐catalytic first‐order reaction, and the degradation stage was a simple first‐order reaction. The rate constants in these two stages at various temperaturs were measured. And the determined apparent activation energies for the gelation stage and for the degradation stage are 27.5±2.0 and 37.7±2.3 kJ/mol, respectively.
Open metallocenes XI. A pentadienyl compound of heavier rare earth element [2,4‐(CH3)2‐η5‐C5H5]3Tb·1/2THF
Authors: Qiu Xin , Liu Ju‐Zheng
Published: September 2010

The reaction of TbCl3 with K[2,4‐(CH3)2 C5H5] at 0°C in THF followed by crystallization at −90°C led to a pale yellow hexagonal prismatic crystalline product [2,4‐[CH3)2‐η5‐C5H5]3‐Tb·1/2THF, which is highly sensitive to air and water and rapidly efflorescent at ambient temperature. The single crystal X‐ray diffraction data of the compound have been collected at low temperature (‐60°C) and the crystal structure has been solved by heavy atom method. It belongs to triclinic system, space group P1 with lattice parameters α=8.477 Å, b=12.583 Å, c=12.858 Å, α=118.08°, β=91.38°, γ=108.75°, V=1120.36 Å3 and Z=2. Least‐squares refinement converged to a final value R=0.043. The compound possesses an idealized C3h symmetry with three 2,4dimethylpentadienyl ligands bound to the central terbium atom in a pentahapto mode (η5). Each unit cell contains two molecules of [2,4‐(CH3)2‐η5‐C5H5]3Tb and one molecule of solvent THF, of which the role in the lattice has been discussed in detail.
Redox properties of (RC2R')Co2(CO)6‐nLn and reactivity of (RC2R')Co2(CO)6‐nLn towards PPh3[LPPh3, P(OEt)3]
Authors: Meng Qing‐Jin , Sun Shou‐Heng , You Xiao‐Zeng
Published: September 2010

Cyclic voltammetric studies of clusters (C5H5‐C2C6 H4‐R‐p)Co2(CO)6‐n Ln[n=0,2; L=PPh3, P(OEt)3] and (RCH2C)2Co2(CO4) (PPh3)2 on Pt electrode are described. The primary reduction (0 / −1) and oxidation (+ 1 / 0) steps are considered as a mono‐electron process for all clusters. For the clusters (C5H5C2C6H4‐R‐p)Co2(CO)6, a good linear relation between reduction potential Epred and Hammett constant σp of R in the clusters is found. For the clusters (RC2R')Co2(CO)4L2, their radical anions are extremely unstable at room temperature and fragment into a series of mononuclear species, one of which is (RC2R')Co(CO)2PPh3. The reaction of radical anions of (RC2R')Co2(CO)6–n (PPh3)n(n=0,2) with PPh3 also produces mononuclear species (RC2R')Co(CO)2PPh3 which has been detected by means of cyclic voltammetry and ESR. The influence of R on redox properties of clusters is discussed.
Co‐deposition of lithium with rare earth from molten chlorides
Authors: Chang Kai‐Guo , Zhao Min‐Shou
Published: September 2010

The possibility of co‐depostion of Li (I) with RE (I) has been investigated. The influences of temperature and concentration of chlorides on the deposition potential have been studied. Linear scanning voltammetry, cyclic voltammetry and current reversal chronopotentiometry were used to study the co‐deposition process. Both the electrochemical and electrolytic results clearly showed that Li (I) and RE (I) could co‐deposit on the aluminum‐copper electrode under selected conditions. Small amount of rare earth element behaved excellently as grain refiner in aluminum—lithium alloy.
Rayleigh relaxation of pyrazine, pyridine and piperidine molecules adsorbed on the roughened Ag electrode by light beating technique
Authors: Wu Guo‐Zhen
Published: September 2010

The light beating technique (intensity correlation algorithm) was employed to analyze the Rayleigh scattering from the roughened Ag electrode in very dilute (10−4 M) pyrazine, pyridine and piperidine aqueous solutions containing KC1 (0.1 M). The relaxation time is longer when the applied voltages are between −0.4 V and −0.8 V (vs. SCE) where the Raman effect also shows greater surface enhancement. Also observed was that for the piperidine case the relaxation time reaches its maximum at the more negative applied voltage. The origin of the relaxation is attributed mainly to the desorption process of the pyrazine, pyridine and piperidine molecules off the roughened Ag electrode. An electrostatic model was also proposed for the interpretation of these experimental observations.
Synthesis and reactions of 4‐aryl‐1(2H) phthalazinones
Authors: Sayed M.A. , Islam I. , Mohamed A.A. , Soliman A.Y. , Bakeer H.M.
Published: September 2010

The behavior of 4‐aryl‐1(2H)‐phthalazinones (1a—c) toward some electrophilic and nucleophilic reagents has been described with the aim of preparing some new phthalazinone derivatives of the expected pharmacological or biological activities.
Synthesis and structure of ethyl (Z)‐α‐formylamino‐β‐arylacrylates
Authors: Han Ying‐Lin , Hu Hong‐Wen , Zhou Zhong‐Yuan , Yu Kai‐Bei
Published: September 2010

Ethyl (Z)‐α‐formylamino‐β‐arylacrylates were obtained in good yields by the condensation of ethyl N, N‐diformylamino acetate and aromatic aldehydes in the presence of sodium ethoxide in ethanol. The structure of ethyl α‐formylaminocinnamate was characterized by single crystal X‐ray diffraction measurement.
Synthesis and characterization of molecular sieve Ni‐ZSM‐5 and its single crystal
Authors: Yao Shang‐Qing , Qiu Shi‐Lun , Pang Wen‐Qin , Sun Tie , Jiang Da‐Zhen
Published: September 2010

Using tetrapropylammonium bromide (TPABr) as a template, molecular sieve Ni‐ZSM‐5 and its single crystals were synthesized in a nonalkaline system in the presence of fluoride ions. By means of XRD, IR, EPMA, MAS NMR, EPR, DTA and H2‐TPR techniques, it is proved that the hetero‐atom, nickel, is really located in the zeolite framework. And finally, Ni‐ZSM‐5 was found to have high catalytic cracking reactivity.
Catalysis of dioxygen reduction at soluble polyaniline modified electrode
Authors: Jiang Rong‐Zhong , Dong Shao‐Jun
Published: September 2010

A reflux‐treatment of soluble polyaniline (SPA) in dimethylformamide (DMF) containing CoCl2 yields an active catalyst for dioxygen reduction which can be adsorbed on the electrode surface firmly. The catalytic reduction of dioxygen at the glassy carbon (GC) electrode modified by the catalyst was studied with cyclic voltammetry (CV), rotating disk electrode (RDE) and rotating ring‐disk electrode (RRDE). The kinetic process of dioxygen reduction at the modified electrode was analyzed with a new RRDE theory dealing with a nondiffusion‐controlled process on ring electrode. The rate constants for each scheme of dioxygen reduction were calculated, showing that only 2‐electron reduction to H2O2 was conducted at the modified electrode. The effect of solution acidity on the electrocatalytic behaviour for dioxygen reduction was investigated. A possibility of initiating catalytic activity for dioxygen reduction was explored with ESCA method.
Bilayer characteristics and cholesterol effects of sodium dialkylmethyl sulphates
Authors: Lei Xue‐Gong , Li Zi‐Zhong , Liu You‐Cheng
Published: September 2010

The gel‐liquid crystal phase transitions (PT) in bilayers formed from a series of synthetic sodium dialkylmethyl sulphates have been studied by both fluorescence and differential scanning calorimetry (DSC) methods, which are between the transitions of the corresponding phospholipids and the quarternary ammonium salt bilayers possessing the same hydrocarbon chains. The fluorescence I3/I2 ratio (R) of probe pyrene in the bilayers decreases below and increases above the transitions respectively with increasing the chain length of the surfactants in the series SUDS, SPHS, and SHOS. In addition, the difference between the R above and below the transition (ΔR) is larger in the suspension prepared at the temperature above that of the transition than in that formed at room temperature. Intermembrane transfer and transbilayer migration (flip‐flop) evaluated by means of DSC of a mixture of equimolar aqueous dispersions of SHOS and SPHS as well as by ESR of bilayer embedding the stable free radical 4‐HD‐TEMPO in the presence and absence of excess ascorbic acid take place noticeably only at the temperature above that of the transitions. Cholesterol has shown the same effect on ΔR as to decrease the length of the alkyl chain of the surfactants. It also causes a decrease of the fluorescence Intensity ratio of excimer to monomer of pyrene, Ie/Im(S), in both phase. The results are discussed in terms of bilayer structure, chain fluidity, and permeability of water.
Studies on sulfinatodehalogenation. XX. Sodium dithionite‐initiated addition of per‐ and polyfluoroalkyl iodides to cyclic enol ethers and chemical conversions of the products
Authors: Huang Wei‐Yuan , Xie Yuan , LÜ Long
Published: September 2010

Per‐ and polyfluoroalkyl iodides [RFI, RF=Cl(CF2)4, 1a; Cl(CF2)6, 1b; Cl(CF2)8, 1c; n‐C6F13, 1d; n‐C8F17, 1e] reacted with cyclic enol ethers such as 2,3‐dihydrofuran (2) and 3,4‐dihydro‐2H‐pyran (3) in aqueous acetonitrile in the presence of sodium dithionite and sodium bicarbonate at room temperature (10–15°C) to give the corresponding 2‐(F‐alkyl) hemiacetals in high yields. The adducts were oxidized with Ce(NH4)2(NO3)6 in acetonitrile or reduced with LiAlH4 in ether to form the corresponding 2‐(F‐alkyl)lactones or diols respectively in good yields. In the presence of p‐toluenesulfonic acid, the adducts were refluxed in benzene and CH3CN to produce the corresponding 2,3‐dihydro‐4‐(F‐alkyl) furan and 3,4‐dihydro‐5‐(F‐alkyl)‐2H‐pyran. This is a new and effective method for preparing these useful organofluorine compounds.
Study on the condensation and crosslinking reactions of furfuryl alcohol and tris(2‐hy‐droxyethyl)isocyanurate by thermal methods
Authors: Chen Xue‐Si , Zheng Guo‐Dong , Liu Zhen‐Hai , Xu Ji‐Ping
Published: September 2010

Condensation and crosslinking reactions of furfuryl alcohol (FA) and FA with tris (2‐hydroxyethyl )isocyanurate (THEIC) are studied by means of DSC, TG, TBA, NMR and elemental analysis. Four exothermic peaks are observed on the DSC curves of thermal condensation of FA and FA with THEIC in the presence of sulfuric acid. The peaks I, II (50–80°C), III (110–130°C) and IV (150–190°C) correspond to linear polycondensation of FA through head‐to‐tail condensation, head‐to‐head etherification, crosslinking dehydration reaction between methylene group and terminal hydroxy group of FA polymeric chain and to further crosslinking reaction at higher temperature, respectively. The reactivity of FA and THEIC increases sharply at 130–150°C and THEIC is reacted completely at 150°C. Addition of THEIC raises the initial decomposition temperature of FA polymer by 60°C.
Study on the complex‐formation reaction of yttrium with para‐methyl‐chlorophosphonazo(CPApM)
Authors: Du Ying‐Xiang , Xu Zhong‐Jun , Hsu Chung‐Gin , Pan Jiao‐Mai
Published: September 2010

Yttrium forms with CPApM a 1:2 α‐complex instantaneously in acidic medium. At pH∼5 (buffer solution), the α‐complex is transformed to a β‐complex with an absorption peak at 755 nm after standing. The transformation reaction is a first‐order reaction. The rate constant and the apparent activation energy were found to be 9.67 × 10−1 min−1 and 52.3 kJ·mol−1 respectively. The mechanism of the reaction shows that the β‐complex (Y:CPApM=2:4) is formed by combining two molecules of α‐complex with the liberation of one proton.
Reactivity of 6‐anisyl‐5‐cyano‐4‐oxo‐2‐thioxo‐1,2,3,4‐tetrahydro‐pyrimidine to wards some electrophiles and nucleophiles
Authors: Hassan M. F. Madkour , Sayed Mahamed A. E. , Ashraf A. Hamed , Adel M. Gaber , Abd El‐Khalik A. Hataba
Published: September 2010

The title compound was subjected to react with some electrophiles and nucleophiles, such as alkyl halides, ethyl chloroacetate or amines, hydrazines etc. The resulting compounds were used in further syntheses for the purpose of obtaining some new types of heterocycles with possible biological and pharmaceutical activities.
Circular dichroism of tail‐to‐tail bisbenzyliso‐quinoline and the absolute configuration of daurisoline isolated from Menispermum dauricum
Authors: Kong Rong‐Zu , Kuang Dai‐Wu , Hua Wei‐Yi , Min Zhi‐Da , Zhao Shou‐Xun , Mizuno Mizuo , Iinuma Munekazu , Tanaka Toshiyuki
Published: September 2010

Since two asymmetric centres are usually present in the bisbenzylisoquinolines, the circular dichroism is known to be an important method to elucidate their stereochemistry. We studied the relationships of the CD spectra with the stereochemistry of synthetic RR‐(1), SS‐(2), RS‐daurisoline (3) and SR‐daurisoline (4). By comparision of the CD spectrum of natural daurisoline (1) from Menispermum dauricum (Menispermaceae) with those of synthetic enantiomers, the absolute configuration was established as RR‐daurisoline (1).
A study of ion exchange selectivity coefficient by cyclic voltammetric measurement
Authors: Dong Shao‐Jun , Lian Guo‐Hua
Published: September 2010

An equation to express ion exchange selectivity coefficient was derived and used for calculating that of PPY film with the results obtained by cyclic voltammetric measurement. PPY film was synthesized by electrochemical method in aqueous solution using K4Fe(CN)6 as supporting electrolyte, and the anions were doped into the film. Ion exchange behaviour of doped Fe (CN)63‐/4‐ in the PPY film with Cl−, NO3− or F− ions in solution has been studied, and the corresponding ion exchange selectivity coefficients were determined.
Reactions of perchlorofluoro compounds VIII. A structure‐reactivity relationship of perchlorofluoroolefins based on MNDO calculations
Authors: Xu Ze‐Qi , Li Shu‐Sen , Hu Chang‐Ming
Published: September 2010

The electronic structures of 17 perchlorofiuoroolefins and perfluoroolefins were calculated using the MNDO method. Based on these calculations combined with the perturbation theory, a good structure‐reactivity relationship of perchlorofluoroolefins has been established. In the case of internal olefins, the direction of nucleophilic attack is governed not only by the perturbation energy of the ground state, but also by the stability of the anionic intermediate and the activation energy of the reaction.
1,3‐Dinitro‐2‐chloro‐5‐trifluorotoluene and its bridged derivatives I. An investigation on the displacement reactions of bidentate nucleophiles towards aromatic rings
Authors: Ji Jing‐Shun , Chen Mei‐Jin , Wang Qi‐Wen , Sheng Wei
Published: September 2010

The reactions of 1,3‐dinitro‐2‐chloro‐5‐trifluorotoluene (DNCTT) (1) and its bridged compounds with bidentate nucleophiles have been investigated. Primary or secondary diamines and diethylene glycol react with 1 and its bridged derivatives by replacing the substituent group para to CF3, whereas ethanedithiol reacts either by replacing the substituent group para to CF3 or by displacing both groups and a nitro group. The results have been rationalized in terms of electronic effects and nucleophilicity of the nucleophiles.
Studies on sulfinatodehalogenation XIII. Synthesis of 2‐perfluoroalkyl‐2‐deoxy‐D‐glucose, mono‐ and poly‐O‐polyfluoroalkylated‐D‐glucoses
Authors: Huang Wei‐Yuan , Xie Yuan
Published: September 2010

Sodium dithionite‐initiated addition of RFI (1) [RF=1a, Cl(CF2)4; 1b, Cl(CF2)6; 1c, Cl(CF2)6; 1d, n‐C6F13; 1e, n‐C3F17] to the properly protected glucose derivatives 2, 9, 12 and 15 gave polyfluoroalkylated glucose derivatives 7, 11, 14 and 17 respectively in good yields after reduction and deprotection. These compounds are strongly surface active.
Studies on sulfinatodehalogenation XIII. A new sulfinatodehalogenation reagent system: NaHSO3/K3[Fe(CN)6]
Authors: Huang Wei‐Yuan , Zhuang Jin‐Lian
Published: September 2010

The reaction of perfluoroalkyl iodide or perfluoroalkyl bromide with sulfite radical anion (SO2) generated from sodium bisulfite / potassium ferricyanide in water/ DMF at 70—75°C gave the corresponding perfluoroalkanesulfinate in good yield. Furthermore, it was shown that the reagent system can also initiate the addition of perfluoroalkyl iodide to olefins or alkynes at 50—65°C.
In situ aminolysis of 1,2‐epoxy‐penten‐3‐ol
Authors: Lin Guo‐Qiang , Zeng Chun‐Min
Published: September 2010

In situ aminolysis of oxirane prepared from divinylacrbinol (1) via Sharpless asymmetric epoxidation was described where I° and II° amines were employed as nucleophiles.
Variational transition state theory study of the reactions Li + HF and Li + HCl on the BO potential energy surfaces
Authors: Yang Yu‐Wei , Ju Guan‐Zhi , Deng Cong‐Hao
Published: September 2010

Variational transition state theory is used to study the kinetics of the reactions Li + HF and Li + HCl on the BO potential energy surfaces, fitted to ab initio values by Lagana et al. The saddle point, the location of generalized transition state and other kinetic features on the bottleneck of the potential energy surface are obtained. We point out that the location of generalized transition state tends to the direction in which the two atoms with larger reduced mass separate off. It can be determined whether a potential energy surface is accurate or not by a fine analysis of its bottleneck region and a comparison of kinetic calculation with experimental result. This is helpful for building a more accurate potential energy surface.
A cobalt‐selenium cluster with triethylphosphine: preparation and structure of Co6(μ3‐Se)8(PEt3)6·THF
Authors: Hong Mao‐Chun , Huang Zhi‐Ying , Lei Xin‐Jian , Wei Guo‐Wei , Kang Bei‐Sheng , Liu Han‐Qin
Published: September 2010

Co6(μ3—Se)6 (PEt3)6·THF, MW = 1766.4, space group R3, has the trigonal parameters, a= 11.890(2)° Å, α = 92.72(2)°, V = 1670.4 Å3, Z = 1. Mo Ka radiation, λ = 0.71073 Å, Dc = 1.749 g/cm3, μ = 59.18 cm−3, F(000) = 870, R = 0.058 and Rw= 0.067 for 1529 observed unique reflections with I>3α(I). The molecular structure consists of an idealized octahedral Co4—core. The Co—Co distances fall in the range of 2.909—2.912 Å.
A new route for the synthesis of ω‐acyl carboxylic acids
Authors: Wu Shi‐Hui , Zhang Zhi‐Yi , Ma Zhen‐Yong
Published: September 2010

A new method for synthesis of ω‐acyl carboxylic acids is described. Photooxygenation of cyclic silyl enol ethers sensitized by 9,10‐dicyanoanthracene (DCA) provided ω‐acyl carboxylic acids in modest to good yields.
The spin delocalization substituent parameter s̀ 8. The spin‐delocalizing abilities of the nitro, cyano, carbomethoxy, carboxy and carbamyl groups
Authors: Ji Guo‐Zhen , Jiang Xi‐Kui , Shi Wen‐Ting
Published: September 2010

The rate constants (k) of the homo‐cycloaddition reactions of five substituted α,β,β‐trifluorostyrenes (TFS's), i.e. p‐nitrotrifluorostyrene (4), p‐cyanotrifluorostyrene (5), p‐carbomethoxytri‐fluorostyrene (6), p‐carboxytrifluorostyrene (7) and p‐carbamyltrifluorostyrene (8), have been measured in the temperature range of 110–160°C. The s̀mb polar substituent parameters of these TFS's calculated from 10F NMR chemical shifts are: NO2, 0.86; CN, 0.86; CO3CH3, 0.40; CO2H, 0.31; CONH2, 0.10. The spin delocalization substituent parameters σT˙ of NO2, CN, CO2CH3, CO2H and CONH2 are 0.32, 0.38, 0.31, 0.37 and 0.37 respectively. Thus all these electron‐pair attracting groups are also very effective spin‐stabilizers.
Studies on the reactions of silyl enol ether with perfluoroorganic compounds I. The reaction of silyl enol ether with perfluoroalkyl iodide
Authors: Ge Wen‐Zheng , Wu Yong‐Ming , Huang Wei‐Yuan
Published: September 2010

The reaction of silyl enol ethers (1a‐1e) with perfluoroalkyl iodides (2f–2k) initiated with sodium dithionite was studied. α‐Perfluoroalkyl ketones (3) were synthesized in excellent yield by this method. α, β‐Unsaturated fluorinated ketones (4) were obtained easily by dehydrofluorination of the α‐perfluoroalkyl ketones. A radical mechanism was proposed.
A novel method for the synthesis of carba‐DHPG and carba‐ACV
Authors: Liu Yu‐Gang , Fei Chang‐Pei , Chen Te‐Heng , (Chan) Ta‐Hang
Published: September 2010

A new and efficient method for the synthesis of potential antiviral agents Carba‐ACV (3) and Carba‐DHPG (4) is described. The synthesis makes the use of N‐acetylguanine to condense with the corresponding tosylates (16) and (11) under the catalysis of dibenzo‐18‐C‐6, resulting in the desired coupling products (17) and (12) in good yield and in the case of Carba‐DHPG with high regioselectivity.
Structural features of a polysaccharide from the leaves of Thea sinensis
Authors: Fang Ji‐Nian , Zhang Zhi‐Hua , Song Guo‐Qiang , Liu Bai‐Nian
Published: September 2010

A polysaccharide of Thea sinensis, TSA, has been isolated from the fresh leaves as a major fraction of polysaccharides. The mol. wt. was estimated to be 850,000 with [α]D15 + 25.5° (c=0.75, H2O). The component sugars were determined as L‐rhamnose, L‐arabinose, and D‐galactose in molar ratio of 0.54: 1.0: 0.94. The O‐acetyl groups locating on galactose residues position 2 were also identified and the content was 3.8%. The 13C NMR spectrum and CrO3 oxidation of TSA indicated the Rhamnose, Arabinose and Galactose to be in α‐, α‐ and β‐configurations, respectively. Methylation analysis, periodate oxidation, partial hydrolysis and 13C NMR spectrum showed that TSA is a branched galactoarabinan.
Magnetic field effects on photochemical reaction III. Mechanistic study of the photodecarboxylation of arylmethyl esters in micellar solutions
Authors: Tong Zhen‐He , Tung Chen‐Ho , Yuan Long‐Hua
Published: September 2010

Photolysis of benzyl phenylacetate (ACO2A), benzyl p‐methylphenylacetate (BCO2A) and 1‐naphthyl phenylacetate (ACO2Np) in homogeneous and micellar solutions results in products typical of radical coupling reactions and loss of carbon dioxide. The cage effects upon direct photolysis of these esters in acetonitrile are significantly greater than zero and those in SDS or HDTBr micellar solutions are even greater. In the triplet sensitization reaction of ACO2Np in micellar solutions the cage effects are smaller than those obtained upon direct irradiation. However, the application of a 0.05 or 0.2 T external magnetic field in the photolysis in micellar solutions decreases the cage effects dramatically. All these results suggest that the photoextrusions of carbon dioxide from these esters proceed via radical intermediates, and upon direct photolysis the reactive states for the cleavage reaction involve both singlet and triplet excited states.
Electrochemical synthesis and characterization of polydiphenylamine
Authors: Dong Shao‐Jun , Song Fa‐Yi , Li Zhuang
Published: September 2010

Electrochemical oxidation of diphenylamine (DPA) in acetonitrile solution produced an adhesive conducting polydiphenylamine (PDPA) film on the electrode, which exhibited multiple colour variation in a wide range of potential. The polymer was characterized by cyclic voltammetry, FTIR and ESR. The results indicate that the electropolymerization of diphenylamine performs via the 4,4′ CC phenyl‐phenyl coupling mechanism. FTIR, ESR and conductivity measurements for the different states of PDPA show that polydiphenylamine can be reversibly doped and dedoped either chemically or electrochemically. It is evidenced also that there are paramagnetic species—polarons in PDPA supposed to be the current carrier.
Preparation of phenyl substituted propargylic alcohol dicobalt hexacarbonyls and their reactions with active methylene compounds in the presence of acid
Authors: Sun Shou‐Heng , Chen Wei‐Bing , Zhang Wen‐Wei , Li Dong‐Wen , Meng Qing‐Jin , You Xiao‐Zeng
Published: September 2010

Eight new complexes with the formula [PhC2C(OH)R1R2]Co2(CO)4 were prepared from phenyl substituted propargylic alcohols and dicobalt octacarbonyl. The reactions of these propargylic alcohol complexes with active methylene compounds, 2,4‐pentanedione or ethyl acetoacetate, in the presence of an acid, HBF4(40%) + P2O5 (in excess) or BF2·Et2O, at room temperature in dichloromethane were investigated. From the 1‐alkyl substituted tertiary propargylic alcohol complexes, three new conjugated ene‐yne complexes produced by intramolecular dehydration reaction were isolated in high yields (82–95%). On the other hand, four new alkylated complexes were obtained with satisfactory yields (44–66%) from the secondary propargylic alcohol complexes. The influence of other acids, phosphorus pentoxide and polyphosphoric acid, on both dehydration reaction and alkylated reaction was also studied.
Synthesis, structure and properties of an imidazolate bridged copper, zinc binuclear complex
Authors: Mao Zong‐Wan , Chen Dong , Tang Wen‐Xia , Yu Kai‐Bei , Liu Li
Published: September 2010

A new imidazolate bridged Cu2+, Zn2+ binuclear complex [(dtma) CuImZn (dtma)]ClO4 · 2.5H2O taken as active site model for Cu, Zn‐SOD has been synthesized and its crystal structure determined. All the bond lengths, bond angles and the distance between Cu and Zn atoms in Cu‐Im‐Zn core of the model complex are close to those in Cu, Zn‐SOD. ESR parameters of the model complex as a function of pH show that the imidazolate bridge is stable in pH range 10–12, and is broken on Zn side at pH ∼9. With decreasing pH, the imidazole is released at pH ∼4 and the dtma ligand dissociates from the Cu containing fragment at pH ∼2.4.
Photochemical naphthylation at α‐carbon atom of carbonyl and its equivalences
Authors: Wu Bi‐Qi , Zeng Fan‐Wen , Li Wei , Zhao Yong , Wu Guo‐Sheng
Published: September 2010

The photostimulated reaction of halonaphthalene with a series of carbanions derived from propionic acid derivatives in liquid ammonia led to the naphthylation at α‐carbon of the carbanions in an isolated yield ranging from 25% to 86%. In all cases, the dehalonaphthalenes were found to be by‐products and the reaction was inhibited by p‐dinitrobenzene. An electron transfer from the carbanion to the halonaphthalene followed by ejection of halogen led to naphthyl radical, as predicted by comparing the LUMOs of the carbanions and the halonaphthalenes, was involved in the process. Absence of the alkylnaphthalene and 1,2‐dinaphthylalkane in the products indicates the smooth electron transfer between (Naph‐Nu)− and Naph‐X. C‐vs. O‐naphthylation is fully addressed in terms of MNDO calculations and acid‐base principle.
Discontinuous behavior of Rayleigh relaxation in supersaturated aqueous NH4H2PO4 solution
Authors: Wu Guo‐Zhen , Huang Yi
Published: September 2010

The algorithm of Rayleigh intensity correlation is employed for the elucidation of relaxation time constants of the aqueous NH4H2PO4 solution with various concentrations. The result shows that there is a discontinuous (abrupt) increases in the relaxation time constant as the super‐saturation state is reached. This quantity, the relaxation time constant, therefore, can be an order parameter. Also discussed is the dependence of the relaxation time constant on the aggregation number n in (H2PO4−)n. This dependence is complicated and may be crucial in understanding the aggregation process in the supersaturation state.
The influence of medium on the stability of coordination compounds 4. The system In(tiron)−‐NaC1O4‐C2H5OHH2O
Authors: Guo Yu‐Hong , Liang Chun‐Yu , Liu Qi‐Tao
Published: September 2010

The stability constants of complex anion In(tiron)− in mixed solvents of ethanol‐water with weight percentages of ethanol being 0,5,15,25,35 and 50 have been measured spectrophotometrically at 293 K, using NaClO4 as supporting electrolyte with ionic strength ranging from 0.1 to 3.3mol·dm−3. The thermodynamic stability constants of In(tiron)− in various mixed solvents have been obtained by a polynomial approximation equation based on Pitzer's theory. As a comparison, the traditional Debye‐Hückel equation has also been used to treat the same data. The results show that this polynomial approximate method is obviously superior to the old one. It was discovered that there is a linear relation between the thermodynamic stability constants of In (tiron)− and the mole fraction of organic component in mixed solvents or the reciprocal of dielectric constants of mixed solvents. The medium effect and the standard free energy of transfer, ΔG°tr, for the coordination reaction: In3+ + tiron4‐ = In(tiron)− have also been discussed.
A new route to prepare the mixed oxo‐ethylidyne‐capped trinuclear tungsten(IV) cluster and the crystal structure of H2Na3[W3O(CCH3)‐(O2CCH3)6(H2O)3][H2W12O40]·13.5H2O
Authors: Xiu Yu‐Fen , Xu Li
Published: September 2010

The synthesis and the structural characterization of the title compound H2Na3[W3O(CCH3)‐(O2CCH3)6(H2O)3][H2W12O40]·13.5H2O are described. It is known that the mixed oxo‐ethylidynecapped tritungsten cluster can be obtained by Zn dust reduction of Na2WO4·2H2O in acetic anhydride. The title compound has been characterized by X‐ray diffraction, UV/VIS and 1H NMR spectra. The tungsten atoms in the cluster cation and anion are in the oxidation states of W(IV) and W(VI) respectively. The crystal is rhombohedral with the space group R32, a = 17.058 (3)Å, c = 49.665 (9)Å, γ=120°, V=12516(9)Å3, Z=6, final R = 0.037 for 2071 reflections with I ≥3σ (I). Both the cluster cation and anion have a C3 symmetry. The important interatomic distances in angstroms for the cluster cation are: W—W, 2.730(2); W—μ3−O, 2.00; W—O (carboxy1), 2.12; W—Ot 2.18 (2).
Kinetics of tautomerization of 1,3,4,7‐tetramethylisoindole
Authors: Capon B. , Ying Bai‐Ning
Published: September 2010

The kinetics of transformation of 1,3,4,7‐tetramethylisoindole (1) to 1,3,4,7‐tetramethyl‐1H−isoindole (2) in water or in deuterium oxide at various pH or pD at 25°C were measured spectrophotometrically. The results indicated that the transformation of 1 to 2 could be promoted by acid and base. From the solvent isotope effects and the fact that the 1‐position of isoindole nucleus is electron‐rich, the mechanism of this transformation is suggested.
The synthesis of perfluoroalkyl‐substituted tetrakisphenylporphyrins
Authors: Huang Wei‐Yuan , Ma Wu‐Ping
Published: September 2010

Perfluoroalkyl‐substituted tetrakisphenylporphyrins were synthesized through the coupling reaction of perfluoroalkyl iodides (RFI) with the corresponding bromophenylporphyrin under the Cu‐bronze catalysis.
Studies on sulfinatodehalogenation XXIV. Further study on sodium dithionite‐initiated perfluoroalkylation of electron‐rich aromatics
Authors: Huang Wei‐Yuan , Ma Wu‐Ping
Published: September 2010

The application of the sulfinatodehalogenation reaction system for the perfluoroalkylation of electron‐rich aromatics is further studied. It was shown that perfluoroalkyl iodides reacted with polyhydric phenols, N,N−dialkylanilines, 2,5‐dimethylpyrrole, N−methylpyrrole initiated by Na2S2O4−NaHCO3 gave the corresponding perfluoroalkylated products in moderate to good yields.
Kinetic studies of methanol synthesis from CO2+ H2 over copper based catalysts
Authors: Zhu Yong‐Bao , Xu Song‐Yan , Jiang Xuan‐Zhen
Published: September 2010

The catalytic activity for the synthesis of methanol from carbon dioxide and hydrogen was measured on various binary and ternary catalysts containing copper oxide under a pressure of 10 atm. Among these samples the catalysts, CuO/ZnO/γ‐A1203, demonstrated the highest activity and selectivity to methanol; MnO, as third component, had no promotional effect on the activity of methanolformation. Based on a simple power rate law the apparent activation energy estimation and partial pressure dependence measurement were accomplished over eight catalysts. The activation energies varied from 40 to 120 kJ/mol depending on the composition of catalysts. The rates of methanolformation to be 0.3 — 0.9 order in H2 and about 0.1 — 0.2 order in CO2 were reported.
Synthetic and structural chemistry of nickel(II) complexes containing dithiolato and phosphine ligands I. Preparation and crystal structure of Ni2(PPh3)2(edt)2
Authors: Cao Rong , Huang Zhi‐Ying , Lei Xin‐Jian , Kang Bei‐Sheng , Hong Mao‐Chun , Liu Han‐Qin
Published: September 2010

A nickel(II) complex containing both dithiolato and phosphine ligands, Ni2(PPh3)2(edt)2 (edt = SCH2CH2S2‐), has been prepared and characterized by X‐ray diffration. The complex crystallizes in the triclinic system, space group P‐1, with a = 10.693(3), b = 17.457 (6), c = 10.606 (3) Å, α = 102.84(2), β = 96.49 (2), γ = 82.56(3); V = 1906.8 Å3; Dc = 1.439 g·cm−3 for Z = 2; the final conventional R was 0.052 based on 3338 observed reflections. Nickel atoms are linked by two sulfur atoms from two edt ligands with the Ni—Ni distance of 2.893 Å, and each Ni atom is coordinated by one phosphorus atom and three sulfur atoms with a square‐planar geometry, where the average length of Ni—S bond is 2.180 Å and Ni—P bond 2.188 Å. The UV‐Vis and 1H NMR spectra have also been recorded.
Synthesis and crystal structure of a new polynuclear complex with a monomer of (3,4,9,10‐dibenzo‐1,12‐diaza‐5,8‐dioxacyclopentadecane)‐copper(II) (μ‐C1)2 zinc(II) chloride
Authors: Gou Shao‐Hua , Xu Zheng , You Xiao‐Zeng , Zheng Pei‐Ju , Dong Jun
Published: September 2010

A polynuclear complex containing a monomer of Cu(II)‐Zn(II) heterobinuclear unit was synthesized and characterized by IR spectra and magnetic moment. The crystal and molecular structure of the complex, CuZnC19H24Cl4N2O2, was determined by X‐ray diffraction, it crystallized in monoclinic, P21/m, α = 8.812 (2), b = 15.972(3), c = 8.831(1) Å, β = 114.33(1)°, V = 1132.4Å3, Z = 2, De = 1.710 g/ cm3,γ(MoKα) =0.71073 å, μ = 25.227 cm−1, R = 0.051. Rw = 0.063 for 1130 observed reflections with I>3α(1). The coordinated octahedra of Cu(II) and tetrahedra of Zn(II) via bridging CI atoms form a single chain polynuclear complex. The Cu, Zn and bridging Cl atoms are located on the crystallographic symmetry plane m which is perpendicular to 2N and 2O donor plane.
Effects of additives on the aggregation of surfactants: Binding domination
Authors: Lei Xue‐Gong
Published: September 2010

The effects of electrolytes, alcohols, and urea on the aggregation of SDS, CTAB, and Triton X‐100 at 25°C have been investigated by fluorescence probing of pyrene. Both electrolytes and alcohols reduce the critical micelle concentration (CMC) of the ionic surfactants, while the effect of the former is more pronounced. It is shown that the effects of electrolytes mainly depend on the concentrations and especially the valence of the opposite charge ions, and only slightly depend on the same charge ions in respect of ion aggregate of micelle. The logarithm of CMC is not linearly correlated with the concentrations of the counter ion or the electrolytes. The results are rationalized in terms of Hartley's model. Propanol increases the CMC of TX‐100, while electrolytes and urea do not. In all the three kinds of surfactant micelles the excitation spectrum of pyrene slightly red‐shifts (ca. 4 nm) from that in water, but is not affected by the additives. The micropolarity of the environment in which pyrene molecule resides in SDS micelle decreases with the increase of the concentrations of electrolytes. This is not the case when alcohols and urea were added to SDS or to TX‐100. It is suggested that the addition of electrolytes would result in more orderly orientation of SDS molecules. It is the binding strength of the counter ions that dominates the effects of additives on the aggregation of surfactants.
The CO2 laser‐induced radical‐chain reactions between CH3CF2H and chlorine‐atom donors CF2ClCFCl2, CF3CCl3 CFCl3 or CF2Cl2
Authors: Li Fang‐Lin , Shi Ji‐Liang , Bi Qi‐Xiu , Gu Jia‐Liang , Jiang Xi‐Kui
Published: September 2010

The CO2 laser induced room temperature reactions of CH3CF2H or another protium‐donor CH3CHClCH3 with chlorine‐atom donors (Z—Cl) CFCl2CF2Cl, CF2CCl3, CFCl3 or CF2Cl2, have been investigated. Some of these reactions can yield two important monomers (CF2 = CH2 and CF2 = CFCl) for fluoropolymers simultaneously. The yield dependence of these two alkenes on experimental conditions has been studied. A laser‐initiated chain process is supported by identification of Z—H intermediates in these reactions.
The reaction of perfluoroalkanesulfonyl halides VIII. A mild method for introducing BrCF2 group to organic molecules
Authors: Huang Wei‐Yuan , Zhang Han‐Zhong
Published: September 2010

BrCF2SO2Br, prepared from sulfinatodehalogenation of CF2Br2 followed by bromination of the intermediate BrCF2SO2Na, was shown to be a mild and efficient bromodifluoromethylating agent.
The structure of adducts of benzaldoxime and m‐chlorobenzaldoxime dehydrodimers with styrene
Authors: Hu Hong‐Wen , Wei Xu‐Dong , Li Cun , Sun Hong‐Zhe , Yao Yi‐Ming , Zhou Zhong‐Yuan , Yu Kai‐Bei
Published: September 2010

The reaction of m‐chlorobenzaldoxime dehydrodimer with styrene gives two 1:1 adducts. The main product 7 is a bisnitrone. The minor product 8 has been shown by X‐ray diffraction analysis to possess the structure: ArCH(NO)CH2CH (Ph)ONCHAr. The two CN bonds are all in Z configuration. The structure of the adducts from benzaldoxime dehydrodimer and styrene is also assigned.
Calculation of ligand‐field and Stark sub‐levels in laser crystals Nd3+ : KY(WO4)2 and Nd3+ : KGd(WO4)2
Authors: Wang Jian‐Jun , You Xiao‐Zeng , Dai An‐Bang
Published: September 2010

The parameters of ligand field of laser crystal Na3+ : KY(WO4)2 and Nd3+ : KGd(WO4)2 are obtained by a scheme which involved intermediate coupling and ligand field interaction. The calculated Stark‐levels are in good agreement with the experimental values.
Poly‐N‐benzylaniline prepared in perchloric acid—a new soluble semiconducting polymer
Authors: Li Zhuang , Dong Shao‐Jun
Published: September 2010

Chemical or electrochemical oxidation of N‐benzylaniline in perchloric acid solution yields a highly colored polymer—poly‐N‐benzylaniline (PBAn). The polymer has good solubility in a number of organic solvents in either acid or base form. At room temperature, conductivity measurements on pressed pellets of the acid form PBAn give a conductivity of 9.3 × 10−6 S·cm−1. The soluble polymer was analyzed using a variety of common experimental techniques including UV‐vis, IR, NMR, ESR spectroscopy, elemental analysis and electrochemical analysis. All experimental results showed that PBAn has a structure similar to polyaniline with the elimination of some benzyl groups.
Synthesis and spectroscopic characterization of cobalt porphyrins and their catalytic activity towards dioxygen reduction
Authors: Guilard Roger , Barbe Jean‐Michel , Dong Shao‐Jun , Qiu Qing‐Sheng
Published: September 2010

The synthesis and spectroscopic characterization of cobalt(II) 5‐(4‐pyridyl)‐10, 15, 20‐triphenylporphyrin, cobalt(II) 5‐(4‐N‐hexadecylpyridiniumyl)‐10, 15, 20‐triphenylporphyrin bromide and cobalt(II) 5‐(2‐aminophenyl)‐10, 15, 20‐triphenyl‐porphyrin are reported. The corresponding copper and vanadyl derivatives ((TriP)Cu, [(hTriP)Cu]+Br− and [(hTriP)VO]+Br−) were also studied. Each metalloporphyrin was characterized by UV‐visible, ESR and 1H NMR spectroscopy. These metalloporphyrins can be firmly adsorbed on the glassy carbon (GC) surface. The catalytic reduction of dioxygen at GC electrodes modified by these catalysts was studied by cyclic voltammetry (CV). The kinetic process of dioxygen reduction at the cobalt porphyrin‐modified electrodes was studied with a rotating ring disk electrode.
Dehydrogenation activities of highly dispersed transition metal oxides on NaY zeolite
Authors: Gao Zi , Cui Jun , Pu Shu‐Bin
Published: September 2010

Highly dispersed α‐Fe2O3/NaY, NiO/NaY, and CuO/NaY catalyst systems were prepared by impregnation method. Dispersion thresholds of the transition metal oxides on NaY zeolite were determined by XRD phase analysis. The dispersion capacities of the transition metal oxides on NaY zeolite are much lower than that estimated on the basis of a closed packed monolayer in the micro pores. The catalytic activity and selectivity of the highly dispersed oxide catalyst systems for ethylbenzene and cyclohexane dehydrogenation reactions were reported.
Adsorption of phenylalanine from aqueous solution onto active carbon and silica gel
Authors: Zhao Zhen‐Guo
Published: September 2010

The adsorption isotherms of phenylalanine from aqueous solution on active carbon and silica gel at varying pH, and the influence of inorganic salt upon the adsorption have been studied (at 25°C). The adsorption amount of phenylalanine on the silica gel is very low due to the strong adsorption of water by silica gel. The results on the active carbon show: (1) The adsorption is found to be pH‐dependent, within pH 4.1—5.1 it increases with pH, within pH 5.1—11.8 it decreases with pH, at pH 5.1 the adsorption reaches its maximum; (2) The phenylalanine is adsorbed mainly in the form of zwitterion; (3) A certain amount of cations and anions of phenylalanine are also adsorbed with van der Waals interaction; (4) After adding NaCl, the adsorption of phenylalanine increases markedly.
Stereochemical effects in mass spectrometry XI. Negative ion fast atom bombardment mass spectrometry of saccharides and glycosides using phenylboronic acid as reagent
Authors: Li Hong , Yang Hou‐Jun , Chen Shao‐Nong , Chen Yao‐Zu
Published: September 2010

The negative ion fast atom bombardment (NIFAB) mass spectra of mono‐, di‐saccharides and glycosides using phenylboronic acid (PBA) as reagent have been studied. In the ion source, PBA reacts stereospecifically with the molecules containing cis‐vicinal glycols to form characteristic ions, from which the stereo‐isomers of saccharides can be definitely distinguished. Disaccharides and glycosides with β‐glycosidic linkage seem to be unfavorabale to react with PBA, therefore, by comparison of the abundances of the characteristic ions, the configuration of the glycosidic linkage in these compounds may be inferred.
Characterization of various surface Co‐sites on reduced Co–Mo/A12O3 and Ru–Co–Mo/A12O3 catalysts using IR and MS spectroscopies
Authors: Xiao Feng‐Shou , Xin Qin , Guo Xie‐Xian
Published: September 2010

An investigation on adsorption of NO on reduced CoMo/A12O3 and Ru‐Co‐Mo/Al2O3 catalysts has been performed using FT‐IR and MS spectroscopies. IR spectra of NO adsorption showed two bands at 1895 and 1800 cm−1, and NO‐TPD profiles gave rise to several peaks at 353, 423 and 473 K, which are assigned to various Co‐sites on the surface. Compared with Co‐Mo/A12O3, the adsorption rate, binding energy, and amount of NO adsorbed on Ru‐Co‐Mo/A12O2 are very high.