bluuebunny/crossref_metadata_2025 huggingface dataset:
ChemInform Abstract: Synthesis of 2β‐Acyl‐3β‐aryl‐8‐azabicyclo(3.2.1)octanes and Their Binding Affinities at Dopamine and Serotonin Transport Sites in Rat Striatum and Frontal Cortex.
Authors: DAVIES H. M. L. , SAIKALI E. , HUBY N. J. S. , GILLIATT V. J. , MATASI J. J. , SEXTON T. , CHILDERS S. R.
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: (4 + 2)Cycloaddition Reaction of a Ketene Containing Both Acyl and Imidoyl Groups with an Aldehyde: Synthesis, Crystal, and Molecular Structure of 1‐(p‐Bromophenyl)‐4‐(p‐toluoyl)‐1,3‐dihydro‐5H‐(1,3) oxazino(4,3‐c)(1,4)benz oxazine‐3,5‐dione.
Authors: ALIEV Z. G. , MASLIVETS A. N. , KRASNYKH O. P. , ANDREICHIKOV YU. S. , ATOVMYAN L. O.
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: A Novel Method for the Preparation of Macrolides from ω‐ Hydroxycarboxylic Acids.
Authors: SHIINA I. , MUKAIYAMA T.
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: C‐(Dimethylamino)methylene‐P‐phenylphosphine in Reactions with Phosphorylallenes.
Authors: KHUSAINOVA N. G. , IONKIN A. S. , ZVEREV V. V. , ZYABLIKOVA T. A. , IRTUGANOVA E. A. , CHERKASOV R. 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: Total Synthesis of (‐)‐Paeoniflorin
Authors: HATAKEYAMA S. , KAWAMURA M. , TAKANO S.
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: New Amino Acids for the Topographical Control of Peptide Conformation: Synthesis of All the Isomers of α,β‐Dimethylphenylalanine and α,β‐Dimethyl‐1,2,3,4‐tetrahydroisoquinoline‐3‐ carboxylic Acid of High Optical Purity.
Authors: KAZMIERSKI W. M. , URBANCZYK‐LIPKOWSKA Z. , HRUBY V. 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: Asymmetric Synthesis of 3‐Hydroxyprolines by Photocyclization of N‐(2‐ Benzoylethyl)glycinamides.
Authors: WESSIG P. , WETTSTEIN P. , GIESE B. , NEUBURGER M. , ZEHNDER 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: One‐Pot Synthesis of Substituted Allyl‐α‐D‐glucopyranosides by an in situ Anomerization Protocol.
Authors: CHARETTE A. B. , TURCOTTE N. , COTE B.
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: Synthesis of C‐Glycosylacetylenes: Applications to the 2‐Azidosugars.
Authors: JOBRON L. , LETEUX C. , VEYRIERES A. , BEAU 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: Synthetic Approach to N‐Alkylated 2,5‐Diamino‐2,5‐dideoxy‐1,3;3,6‐ dianhydroalditols by Reductive Alkylation.
Authors: LIMBERG G. , THIEM 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: Diastereoselective Synthesis of Glycos‐3‐yl‐α‐amino Esters, e.g. (IV).
Authors: BOUIFRADEN S. , EL HADRAMI M. , ITTOBANE N. , LAVERGNE J.‐P. , VIALLEFONT PH.
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: Ammonium Derivatives of Ajmaline. Synthesis and Experimental Study on Their Antiarrhythmic Activity.
Authors: MININA S. A. , KOSTIN YA. V. , SERGEEVA E. M. , MOLOKHOVA E. I. , KORBELAINEN E. S. , TSYBUSOV A. P. , KUZNETSOVA V. A. , KOMKOV A. P. , VOLKOVA N. D.
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: Aldehyde Intermediates in the Synthesis of Tacamine‐Type Indole Alkaloids: Preparation of (.+‐.)‐Apotacamine.
Authors: TOLVANEN A. , BELLE D. D. , LOUNASMAA 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: Synthesis and Antiviral Activities of 8‐Alkynyl‐, 8‐Alkenyl‐, and 8‐ Alkyl‐2′‐deoxyadenosine Analogues.
Authors: SAGI G. , OETVOES L. , IKEDA S. , ANDREI G. , SNOECK R. , DE CLERCQ E.
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: Synthesis and Conformational Analysis of 2′‐Deoxy‐2′‐(3‐methoxybenzamido)adenosine, a Rational‐Designed Inhibitor of Trypanosomal Glyceraldehyde Phosphate Dehydrogenase (GAPDH).
Authors: VAN CALENBERGH S. , VAN DEN EECKHOUT E. , HERDEWIJN P. , DE BRUYN A. , VERLINDE C. , HOL W. , CALLENS M. , VAN AERSCHOT A. , ROZENSKI 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: A Stereoselective and Convergent Synthesis of a C21‐C34 Fragment (I) of FK506.
Authors: MAIER M. E. , HALLER B.‐U. , STUMPF R. , FISCHER 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: Biological Activity of 7‐Aryl‐3‐methyl‐1‐phenyl‐1H,6H‐pyrazolo(5,4‐b)( 1,4)‐diazepine‐5‐carboxylic Acids and Their Derivatives
Authors: YANBORISOV T. N. , ZHIKINA I. A. , ANDREICHIKOV YU. S. , KOLLA V. E. , DROVOSEKOVA L. P. , KASHINA Z. N. , PLAKSINA A. N. , NOVOSELOVA 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: Amorphous Wires and Their Applications
Authors: SQUIRE P. T. , ATKINSON D. , GIBBS M. R. J. , ATALAY S.
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: Starting Compounds for the Preparation of High‐Temperature Superconducting Films by the CVD‐Method.
Authors: MINKINA V. 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: Meldola Lecture. The Role of Aromatic Interactions in Molecular Recognition
Authors: HUNTER C. 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: Electronic Spectra and Photochemistry of Trichlorostannyl Complexes of Rhodium(III) and Platinum(II).
Authors: PAWLOWSKI V. , KUNKELY H. , VOGLER 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: Principles and Theory of Two‐Cycle Circulation Liquid Chromatography.
Authors: CHIZHKOV V. P. , VARIVONCHIK N. E.
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.
Adsorptive Removal of Alkoxyphenols from Ketones and Esters with Activated Carbon – Experiments and Modelling
Authors: Gräf T. , Pasel C. , Bathen Dieter
Published: September 2010

Hochreine Chemikalien werden vor allem in den Bereichen Elektronik, Optik, Pharmazie und Analytik eingesetzt. Zur Feinreinigung von Flüssigkeiten wird besonders die Adsorption genutzt. Mit Hilfe der hier vorgestellten Adsorptionsmessungen am System Aktivkohle/Alkoxyphenol in Ketonen und Estern als Lösungsmittel wurden Adsorptionsmechanismen untersucht und thermodynamische Gleichgewichtsdaten zur Auslegung von Prozessen erhalten.
Production of H2 and medium heating value gas via steam gasification of lignins in fixed‐bed reactors
Authors: Ferdous Deena , Dalai Ajay K. , Bej Shyamal K. , Thring Ronald W.
Published: September 2010

In this work, steam gasification of Alcell and Kraft lignins were carried out in a fixed‐bed reactor in order to produce H2 and medium heating value gas. The conversion of lignins increased from a low of 64 wt% for Alceil lignin to a high of 88 wt% for Kraft lignin with increasing steam flow rate and temperature. Maximum H2 production of 60.7 mol% was obtained at 800°C and at a steam flow rate of 15 g/h/g of Kraft lignin, whereas maximum heating value of 18000 kl/m3 of the product gas was obtained at 650°C and at 5 g/h/g of Alcell lignin. Also, the performance of a Ni‐based steam reforming catalyst for the production of H2 was studied for both types of lignin in a dual fixed‐bed reaction system. A maximum H2 production of 63 mol% was obtained at a catalyst bed temperature of 750°C and at a catalyst loading of 0.3 g for Alcell lignin. The sulfur present in Kraft lignin had detrimental effect on the catalyst performance.
Photoelectrochemistry of electrochemically deposited cadmium‐rich cadmium mercury telluride films.
Authors: Tan Zheng , Li Jun , Mi Tian‐Ying
Published: September 2010

The potentiostatic deposition of cadmium‐rich CMT films onto Ti, Mo, Ni substrates from an aqueous bath was carried out. The photoelectrochemical properties of film electrodes were investigated when used in a solid‐liquid junction photoelectrochemical cell (PEC). A.C. capacitance was determined.
Studies on silicon‐containing fragrance raw materials I. Syntheses and structure‐odor relationship of acetals of 4‐trimethylsilyl‐3‐cyclohexenone and 4‐trimethylsilylcyclohexanone and their carbon counterparts
Authors: Tang Shi‐Xiong , Li Yue‐Ming , Cao Yu‐Rong , Wang Xiao‐Lan
Published: September 2010

In order to investigate the structure‐odor relationship of odoriferous compounds and search for new aroma chemicals, seven acetals of 4‐trimethylsilyl‐3‐cyclohexenone and their carbon counterparts were synthesized by Birch reduction of 4‐substituted anisoles and then acetalization. Seven acetals of 4‐trimethylsilylcyclohexanone and their carbon counterparts were synthesized similarly. Structures of all new compounds were determined by MS, IR and 1H NMR, and their characteristic odors were evaluated as well.

The characteristic odors of the acetals formed by 4‐substituted‐3‐cyclohexenone and 1,2‐diols are fruity and woody. The acetals formed from 1, 3‐diols are woody, and formed with 1, 4‐diols are very faint in odor. Odors of acetals of 4‐substituted cyclohexanone are all very weak. As a whole, odors of organosilicon compounds are weaker, but somewhat more delicate than their carbon counterparts.
Langmuir‐Blodgett film formation of rare‐earth metal di‐, triphthalocyanine complexes and observation of their thin film by means of TEM and STM
Authors: Liu Yun‐Qi , Zhu Dao‐Ben , Ruan Li‐Ke , Bai Chun‐Li , Yamada Akira , Shigehara Kiyotaka
Published: September 2010

Three different kinds of rare‐earth metal phthalocyanine complexes (Pc2LuH, Pc3Gd2, R12 Pc3Dy2) were synthesized. Their ultra‐thin films were prepared by the Langmuir‐Blodgett technique. Crystallites were observed in Langmuir film of Pc3Gd2 by means of transmission electron microscopy. The limiting molecular areas of the phthalocyanine derivatives on pure water increased in the order mono‐, di‐ and triphthalocyanine, implying that these phthalocyanine molecules are stacked with a face‐to‐face orientation and edge‐on to the water surface. By using scanning tunneling microscopy individual molecules of lutetium diphthalocyanine adsorbed on graphite surfaces were imaged for the first time.
Studies on bio‐antioxidants II. An ESR study on the antioxidant efficiency of ascorbyl palmitate in micelles
Authors: Liu Zhong‐Li , Han Zheng‐Xu , Cheng Pin , Wu Lung‐Min , Liu You‐Cheng
Published: September 2010

The kinetics for the reaction of ascorbyl palmitate and 4‐hydroxy‐TEMPO, 4‐methoxy‐TEMPO or 4‐hexanoyloxy‐TEMPO in CTAB and SDS micelles was studied by ESR spectroscopy. It was found that the behavior of ascorbyl palmitate is remarkably different from ascorbic acid in their antioxidant activity in micelles. The predominant factors governing the activity in micelles involve the lipophilicity of the antioxidant and the oxidant, the charge type of the substrates and the concentration of the surfactant. As high as 2 × 104 fold rate variation was observed by changing the lipophilicity of the antioxidant and the microenvironment of the reaction medium.
Studies on sulfinatodehalogenation XXI. A new and convenient syntheses of 2‐(F‐alkyl) aldehydes, alcohols, acids and ketones
Authors: Huang Wei‐Yuan , LÜ Long
Published: September 2010

Reaction of perfluoroalkyl iodides (1a–e) with the unsaturated ethers such as 1‐ethoxy‐1‐propene (2), 1‐methoxy‐1‐butene (3) under the sulfinatodehalogenation condition gave the corresponding 2‐(F‐alkyl) propanals (5a–e) and butanals (6c, d) very readily in high yield, which were converted to 2,4‐dinitrophenylhydrazones (7a–e, 8c, d) and characterized. The reaction products 5 and 6 were oxidized with Jone's reagent and reduced with NaBH4 in ethanol to give the corresponding acids (9, 10) and alcohols (11, 12) in good yield. Treatment of compounds 5 and 6 with pyridine gave the dehydrofluorination products 13 and 14. Under the same condition, perfluoroalkyl iodide reacted with 2‐ethoxy‐1‐propene (4) only to form RFSO2Na and RFH as the major products, but in aqueuous DMF (DMF: H2O = 5:1) to give the perfluoroalkylacetone (15) in good yield. Thus, the reaction provides a convenient, effective new method for syntheses of these useful organofluorine intermediates.
Behaviour of 4‐(4‐chlorophenyl)‐6‐(4‐tolyl)‐4,5‐dihydro pyrimidine‐2(1H) thione and 2‐hydrazino derivative toward carbon electrophiles
Authors: El‐Hashash M.A. , El‐Kafrawy A.F. , Shiba S.A.
Published: September 2010

The reaction of thiourea with p‐methyl‐β‐p‐chlorophenyl acrylophenone (1) is, in principle, an attractive [3 + 3]‐fragment approach to the synthesis of dihydropyrimidine bearing aryl groups.
ESR studies on reactions of dicyclopentadienyl dicarbonyl titanium with organic halides
Authors: Wang Ji‐Tao , Bai Ling‐Jin , Liu Feng‐Quan
Published: September 2010

ESR method was used to elucidate the mechanism of the reactions of alkyl, allyl or benzyl halides with dicyclopentadienyldicarbonyl titanium. The paramagnetic [intermediates of the reactions were identified during the course of the reactions. The reaction mechanism based on ESR findings and the products analyses is postulated to operate on radical pathways. When alkyl halides were used to react with the organometallic compound 1, the intermediate found was [Cp2Ti(CO)X] (C), and the main product was identified to be dicyclopentadienyl‐acyl‐halo titanium (3), an insertion of TiCO into R‐X, i.e. [Cp2Ti‐C(0)R] X. When allyl or benzyl halides were used, the intermediate found was [Cp2TiX] (B), and the main products were identified to be the dicyclopentadienyl titanium dihalides and the coupling products of allyl or benzyl groups.
13C NMR study ofD‐pantothenic acid complexes with heavy lanthanide ions in aqueous solution
Authors: Ren Ji‐Min , Pei Feng‐Kui , Wang Wen‐Yun
Published: September 2010

The13C NMR study of the interaction between the trivalent lanthanide ions (from Dy to Lu) andD‐pantothenic acid in aqueous solution was presented. The unambiguous resonance assignments were made on the basis of pH dependence and the analysis of molecular geometry.13C paramagnetic shifts were separated into the contact and dipolar components by Reilley's method. The complex stability constant is 12.0 L / mol for the 1:1 ytterbium complex. An analysis of the shift data shows that heavy lanthanide ions form isostructural complexes with the substrate and the hyperfine coupling constant is independent of the ions used in the study.D‐pantothenic acid is coordinated to the metal via the two oxygens of the carboxyl group with 2.25Å of Ln—O distances. The electron spin density distribution and the structural details of the complex were elucidated from the shift data. It is stated that contact contributions, while small for nuclei of several bonds away from the metal, should not be dismisseda priori.
Optimization of multicomponent solvent selection in high‐performance liquid chromatography using a statistical method
Authors: Wang Qin‐Sun , Gao Ru‐Yu , Wang Heng‐Yan , Yan Bing‐Wen
Published: September 2010

A computer‐assisted method is presented for optimization of multicomponent solvent mobile phase selection for separation of O‐ethyl‐N‐isopropyl phosphoro (thioureido) thioates in reversed‐phase HPLC and four geometric isomers of pesticides Decis in normal‐phase HPLC. The method is based on Snyder's solvent selection triangle concept using a statistical method. The optimization of the separation over the experimental region is based on a special polynomial estimation from seven experimental runs, and resolution (Rs) is used as the selection criterion. Excellent agreement was obtained between predicted data and experimental results.
Separation mechanism of chiral compounds in chiral stationary phase liquid chromatography
Authors: Zou Han‐Fa , Zhang Yu‐Kui , Lu Pei‐Chang
Published: September 2010

In this paper, the concept of reversed‐ or normal‐phase chiral stationary phase liquid chromatography has been put forward according to the polar strength of mobile and stationary phases. The statistical model developed in HPLC has been used to investigate the separation mechanism of D‐ and L‐enantiomer in chiral stationary phase liquid chromatography. It has been observed that the variation of capacity factor of enantiomers with mobile phase composition in both reversed‐phase and normal‐phase chiral stationary phase liquid chromatography can be described by the fundamental elution equation lnk' = a + blnCb + cCb. The effect of mobile phase composition on the selectivity of enantiomers D and L in normal‐phase chiral stationary phase liquid chromatography can be described by the equation lnα = Δa + ΔblnCb, but in reversed‐phase chiral stationary phase liquid chromatography the selectivity is almost independant of the mobile phase composition.
The prediction of the peak width at half height in HPLC
Authors: Zou Han‐Fa , Zhang Yu‐Kui , Lu Pei‐Chang
Published: September 2010

The prediction of the peak width at half height is an important aspect in the optimization of the chromatographic operating conditions. In this paper, a linear relationship, between the peak widths at half height and the retention values with various isocratic elution is observed. In gradient elution, however, the relationship between the peak widths at half height and the so‐called invented retention values that correspond to the mobile phase composition by eluting the solute from the column end is developed. We believe that there is almost the same band width at half height inside the column (in unit of length) for different solutes. The peak width at half height in the chromatogram (in unit of time) is mainly determined by the capacity factor of the solute when it is eluted from the column end. The larger the capacity factor of a solute eluted from the column end, the more slowly will be the solute eluted from the column end and the wider will be the peak width at half height. It is possible to predict the peak width at half height in various isocratic and gradient elutions by using this linear relationship.
C‐Alkylation of α‐acylamino ketones. A versatile synthesis of α‐alkyl α‐amino ketones
Authors: Han Ying‐Lin , Hu Hong‐Wen
Published: September 2010

C‐Alkylation of some α‐acylamino ketones were achieved with alkyl halides by means of sodium ethoxide in ethanol. The present paper deals with the C‐alkylation of N,N‐diformylamino ketones and the difference in stability of the amide group.
Studies on sulfinatodehalogenation XXIII. A new sulfinatodehalogenation reagent: thihurea dioxide1
Authors: Huang Wei‐Yuan , Zhuang Jin‐Lian
Published: September 2010

HSO2− generated from thiourea dioxide and sodium bicarbonate in aqueous CH3CN at 35–45°C reacted with perfluoroalkyl iodides, polyfluoroalkyl bromide, 1,1,1‐trichloro‐2,2,2‐tri‐fluoroethane and carbon tetrachloride to give the corresponding sulfinates in good yield. Furthermore, it was shown that the reagent was able to initiate the addition of perfluoroalkyl iodide to olefins and alkynes at 30°C.
Carbonium cyclization—studies on lignans containing the dibenzocyclooctadiene system, I
Authors: Tan Rui , Zheng Qi‐Tai , He Cun‐Heng , Liang Xiao‐Tian
Published: September 2010

The reaction of schisandrin (1) under Ritter reaction conditions (cone, sulfuric acid / acetonitrile) was studied. Besides trace amounts of normal products (7α‐ and 7β‐acetamido derivatives 2a and 2b), the main product was a carbonium cyclization compound (3a).
Anharmonic oscillator model of overtone spectra for D3h symmetry molecules
Authors: Wang Yi‐Fei , Liang Ying‐Qiu , Tang Ao‐Qing
Published: September 2010

The bond stretching vibrations of XF5 molecules with D3h symmetry are treated computationally on the Morse oscillator model in which the bond oscillators are coupled harmonically. Each calculation involves four parameters for two types of Morse potential and three parameters for the kinetic‐energy, potential coupling terms. The eigenvalue formula for overtone and combination states up to three are presented and can be used to predict all the vibrational energy levels from local mode molecules through normal mode molecules. For PF5, AsF5 and VF5, the coupled Morse oscillator model gives a prediction in good agreement with the experimental data.
Photophysics studies of organic compounds VIII. Interaction between excited singlet state of pyrene and aromatic amines
Authors: Chen Feng‐Qi , Yu Qun , Meng Xian‐Juan , Shou Han‐Shen , Fan Mei‐Gong
Published: September 2010

The quenching processes of the excited singlet state of pyrene by triphenylamine, diphenylamine and N,N‐dibenzylaniline in various solvents at room and lower temperature have been studied with both static state fluorescence spectroscopy and fluorescence lifetime techniques. On the basis of experimental data, a preliminary quenching mechanism has been discussed. The geometrical configuration models of the exciplexes formed between the excited pyrene and aromatic amines in nonpolar solvents were proposed.
The crystal structure and conformation of N‐[2,2‐dimethyl‐3‐(2‐methylpropenyl)‐ cyclopropylcarbonyl]‐5‐methylisoxazolin‐3‐one
Authors: Xue Jie‐You , Shao Rui‐Lian , Zhu You‐Quan , Yao Xin‐Kan , Wang Hong‐Gen
Published: September 2010

The title compound has been synthesized and its crystal structure was determined by X‐ray crystallographic method. The crystal is triclinic, space group P‐1, with unit cell dimensions a = 6.146 (5), b = 8.473(6), c = 14.383(5) Å; α = 77.47 (4), β = 82.84 (4), γ = 69.00 (8)° and Z = 2. The results obtained reveal that the molecule of the title compound keeps a long conjugative system involving CC double bond, cyclopropane ring, carbonyl group and isoxazolinone ring and adopts a low energy conformation including s‐trans of CC double bond, s‐cis of carbonyl group with respect to the three‐membered ring and like‐s‐trans of carbonyl group with the carbonyl group within the heterocyclic moiety.
Cumulative potential‐derived atomic multipoles
Authors: Kong Jing , Yan Ji‐Min
Published: September 2010

A method to derive the atomic multipole moments cumulatively up to quadrupole moments was developed. The multipole moments are obtained by least‐square simulating the molecular electrostatic potentials. Only the components of the term of highest order in the atomic multipole expansion are optimized while the lower terms remain fixed. The calculations on HF, H2O and NH3 show that the cumulative method can give reasonable qualitative and fairly good quantitative results.
A crosslinked chiral stationary phase for the separation of enantiomers by gas and supercritical fluid chromatography
Authors: Zhou Liang‐Mo , Lou Xian‐Wen , Sheng Yu‐Fong , Wang Qing‐Hai , Zhu Dao‐Qian
Published: September 2010

Crosslinking experiments for the chiral stationary phase OV‐225‐L‐Val‐t‐butylamide within both fused silica and glass capillary columns have been carried out. Amino acid enantiomers were separated on crosslinked columns by both GC and SFC methods. In SFC, the a values of amino acid enantiomers are independent of the density of the mobile phase, and they are hig her than those obtained by GC for the tested enantiomers with the same column due to the lower column temperature used in SFC.
The structure correction of “8‐hydroxysubspinosin” and synthesis of 5‐hydroxydamnacanthol‐ω‐ethyl ether
Authors: Yu Ju‐Rong , Cal Jun‐Chao , Gao Yi‐Sheng
Published: September 2010

8‐Hyaroxysubspinosin was elucidated as 2,8‐dihydroxy‐3‐ethoxymethyl‐1‐methoxyanthraquinone (2) in the literature. Here, the structure revision and synthesis of 8‐hydroxysubspinosin were presented. It should be revised to 3,5‐dihydroxy‐2‐ethoxymethyl‐1‐methoxyanthraquinone (5), i.e. 5‐hydroxydamnacanthol‐ω‐ethyl ether by comparison with the synthetic sample. 5 was synthesized by alkylation of 3‐bromo‐7‐methoxyphthalide (10) with 2,6‐dimethoxytoluene in the presence of stannic chloride, followed by reductive cleavage, cyclization, oxidation, demethylation, selective acetylation, methylation, bromination and condensation with sodium ethoxide. The isomer 1,3‐dihydroxy‐2‐ethoxymethyl‐5‐methoxyanthraquinone (5b) was also obtained.
A formal synthesis of (—)‐patchouli alcohol from (—)‐carvone
Authors: Zhao Rong‐Bao , Wu Yu‐Lin
Published: September 2010

Enantiomerically pure 6‐acetyl‐1,3,3‐trimethyl bicyclo[2.2.2]octan‐2‐one, a key intermediate for synthesis of (‐)‐patchouli alcohol, was facilely synthesized from the adduct of a monomethylated (‐)‐carvone 2 and methyl acrylate.
A comparative study of the aromaticity in some typical conjugated six‐membered rings by the method of localized molecular orbital
Authors: Chen Zhi‐Da , Lu Jia‐Xi , Li Jun , Liu Chun‐Wan , Zhang Qian‐Er
Published: September 2010

The localized molecular orbitals and energy levels for four typical conjugated six‐membered ring systems C6H6, C3N3H3, B2N8H4, and (B2O4)3‐ as well as a non‐aromatic reference molecule Pa‐N3Cl6 have been calculated by using Edmiston‐ Ruedenberg energy localization technique under the CNDO / 2 approximation in order to investigate the nature of aromaticity or quasi‐aromaticity of the six‐membered ring systems studied. The contour maps for x‐type localized MO's (LMO) have been plotted to illustrate the bonding characteristics of the five ring systems studied. These LMO calculations show that for all the conjugated six‐membered ring systems considered there exists local delocalization of x‐bonds or three‐centered and occasionally four‐centered two‐electron x‐bonds in our terminology, and the cooperative effect among these x‐bonds leading to the formation of a closed continuous x‐conjugation system around the ring, which is necessary for the creation of aromaticity in the systems studied. We have been able to discuss the properties of these three‐centered x‐bonds in terms of the constituent atoms and electrons and the relevant orbitals involved.
Determination of HMO parameters with MS‐Xα‐SCF method
Authors: Wang Yi , Li Le‐Min
Published: September 2010

A technique for determining the HMO parameters with MS‐Xα‐SCF method has been developed. The ionization potentials of even polyenes and condensed benzene compounds have been calculated. The average deviation from the existent experimental values is 0.34 eV.
Thermodynamical study on the formation of some mixed ligand complexes of non‐transition metal ions in solution I. The formation and the stability of some Pb(II) mixed ligand complexes
Authors: Liu Qi‐Tao , Zhang Feng , Song Xi‐Ming , Gao En‐Jun
Published: September 2010

The stability constants of the binary complexes of type PbB, PbB2, and the mixed ligand complexes of type PbAB have been studied by potentiometric pH titration technique at ionic strength I = 0.10 (KNO3) and at temperature 15, 25, 35 and 45°C respectively, where A = 2,2′‐bipyridyl (bipy) or 1,10‐phenanthroline (phen); B = malonate (mal), succinate (suc), or anthranilate (anth). The equalibrium constants ΔlogK,1 ΔΔG, ΔΔH, and ΔΔS of the reaction PbA + PbB = PbAB + Pb2+ have been calculated. The results show that the discriminating effects2 between the primary ligand (bipy or phen) and the secondary ligand (mal, suc or anth) in those non‐transition metal mixed ligand complexes are also evident, and as a measurement of this effect, ΔΔH is more appropriate than ΔlogK. The possible reasons which lead to these results have been discussed.
Fluorometric determination of trace selenium in β‐CD/SDS aqueous solution
Authors: Lu Dan‐Hong , Zheng Yong‐Xi
Published: September 2010

A proper mixture of β‐cyclodextrin and sodium dodecylsulfate in aqueous solution was found to show a synergistic enhancement of the fluorescence intensity of 4,5‐benzopiaselenol. The determination of trace selenium can be carried out directly in aqueous solution.
Expert systems for HPLC in biochemistry—The knowledge base for selection of HPLC column system in the separation of amino acids, peptides and proteins
Authors: Zhang Yu‐Kui , Zou Han‐Fa , Lu Pei‐Zhang , Yao Zhi‐Jian
Published: September 2010

The strategy of expert system for high performance liquid chromatography was discussed, the attentions are mainly placed on the knowledge base for selection of column system, separation modes and detection modes in the analysis of amino acids, peptides and proteins.
Structural effects of multiple‐bonds on aggregating tendencies of long‐chain esters
Authors: Jiang Xi‐Kui , Ji Guo‐Zhen , Luo Guang‐Lin
Published: September 2010

The kinetics of the hydrolysis of p‐nitrophenyl esters of three types of single‐chain carboxylic acids, namely, saturated, olefinic and acetylenic, was investigated in two aquiorgano binary solvent systems, DMSO‐H2O and dioxane (DX)‐H2O. The ester probes used are: octanoic (C8), dodecanoic (C12), stearic (C18), oleic (C18‐ol), elaidic (C18‐el) and stearolic (C18‐st). The order of measured CAgC values is: C18‐ol>C18‐el>C18>C18‐st, whereas the order of decreasing magnitude of the observed hydrolytic rate constants of the monomeric species (km) is: C18>C18‐el>C18‐ol> C18‐st. These rather unanticipated results are discussed.
Linear dependence of the degree of aggregation on the solvent aggregating power (SAgP)
Authors: Jiang Xi‐Kui , Ji Guo‐Zhen , Luo Guang‐Lin
Published: September 2010

With k8/k16, the ratio of the hydrolytic rate‐constants of p‐nitrophenyl octanoate (C8) to hexadecanoate (C16), as the indicator of the degree of aggregation, the linear dependence of the degree of aggregation on solvent aggregating power (SAgP) has been established in five aquiorgano solvents, each within a certain range of volume fraction (ϕ values) of the organic cosolvent. The meaning of this linearity has been discussed.
Nitriles in heterocyclic synthesis: Studies on ethyl 3‐amino‐4,4‐dicyano‐3‐butenoate
Authors: Soliman A.Y. , Bakeer H.M.
Published: September 2010

New polyfunctionally substituted heterocyclic compounds were synthesized from ethyl 3‐amino‐4,4‐dicyano‐3‐butenoate (1) as a starting material.
A comparison of the determination of stability constants of complexes of Pb(II) with amino acids using micro‐pH‐metric titrations and cyclic voltammetry
Authors: Lu Ai‐Ru , Pettit D. Leslie , Bernard Gareth , Gregor E. Jan
Published: September 2010

This paper reports the determination of stability constants for complexes of Pb(II) with Gly, Ala, Asp and Gly‐Gly using both micro‐pH‐metric titrations and the application of convolution‐de‐convolution cyclic voltammetry at 25°C and I = 0.10 mol·dm−3 (KNO3). Stability constants were calculated from pH‐metric data using the SUPERQUAD computer program and cyclic voltammograms were collected, stored and manipulated using the E G and G CONDECON 300 software. A′ considerably larger ligand: metal ratio (e.g. 50:1) was possible using voltammetry. Under these conditions, hydroxy complex formation was minimised and the formation of bis‐complexes optimised. Computer based calculations were carried out on PC‐compatible microcomputers fitted with mathematics coprocessors. Evaluation of results from the two techniques suggests that stability constants for the species [PbL2] are reliable when calculated from voltammetry while those for [PbL] are more reliable when determined by pH‐metric titration.
Determination of trace silver in waste water by 9,10‐dimethylacridinium fluorosulfonate‐K2S2O8 chemiluminescence system
Authors: Lin Jin‐Ming , Zhang Fan
Published: September 2010

A new highly sensitive method for determination of trace silver in waste water with 9,10‐dimethylacridinium fluorosulfonate (DAFA)‐K2S2O8 system was suggested. In the basic aqueous solution, trace of silver (I) showed strongly catalytic effect on the chemiluminescence system with the presence of 2,2′‐bipyridine. The range of the linear relationship between light intensity and concentration of silver (I) is 1.0 × 103 mol / L to 6.0 × 103 mol / L. The detection limit is 8.0 × 103 mol / L, and the RSD for 5.0 × 103 mol / L Ag (I) is 6.5% (n=13). In the existence of potassium fluoride, the selectivity is higher. Combining the treatment with nitric acid, the method is applied to determine some environmental waste water and the results are similar to atomic absorption spectroscopy.
Sensitized photooxygenation VI. Kinetic studies on the singlet oxygenation of 6‐ethyl‐3, 4‐dihydro‐2H‐pyran‐5‐carboxylic acid ethyl ester and 6‐isopropyl‐3,4‐dihydro‐2H‐pyran‐5‐carboxylic acid ethyl ester
Authors: Huang Ze‐En , Liang Xiao‐Guang , Leung Hiu‐Kwong , Chan Yuk‐Yee
Published: September 2010

Kinetic studies of the singlet oxygenation of the title compounds were performed according to Monroe's method. The reaction rate increases with temperature decreasing, leading to a negative activation enthalpy and a large negative activation entropy. These data are interpreted as the evidence for the intermediacy of an exciplex. The solvent effect on the reaction rate suggests that the “dioxetane” path involves a transition state or an intermediate with significant zwitterionic character. The electronic effect of the substituent is obvious, with electron‐withdrawing substituent retarding the reaction and electron‐donating substituent increasing the reaction rate. However, steric bulkiness at the 6‐position does not play an important role in the reaction rate.
Interaction of cyclodextrins with 1,3‐di(1‐naphthyl)propane and the additive effects of ionic surfactants
Authors: Xie Rui‐Qiang , Lei Xue‐Gong , Liu You‐Cheng
Published: September 2010

The interaction between cyclodextrins (CDs) and 1,3‐di(1‐naphthyl)propane (1) in aqueous methanol (V:V=1:1) has been investigated by means of fluorescence emission and UV absorption. Fluorescence enhancement and absorption spectra reveal that β‐ or γ‐CD can form inclusion complexes with 1, but a‐CD cannot. One of these complexes is identified as ground state complex (2:1), i.e. the eclipsed conformer of 1 is included. Molecule 1 can be driven out of the CD cavity by sodium dodecylsulfate (SDS) molecule, but cannot by cetyltrimethylammonium bromide (CTAB) or sodium cetylsulfate (SCS) molecules due to their alkyl chain coiling.
Geometry optimization and electronic structures of molecules H3AXAH3
Authors: Wang Zhi‐Zhong , Shen Er‐Zhong
Published: September 2010

The geometries of molecules H3AXAH3 (X=O, S, Se and A=C, Si) have been optimized using STO‐3G ab initio calculations and gradient method and the results are in good agreement with reported experimental values. From the STO‐3G optimized geometries, we have also calculated the electronic structures of these molecules using 4–31G and 6–31G basis sets to obtain the MO energies, atomic net charges and dipole moments. The ionization potentials calculated by 6–31G basis set are in good agreement with experimental values.
Crystal structure of K6CrNb15O42
Authors: Wu Bo‐Lin , Zha Cong‐Ji , Yuan Run‐Zhang
Published: September 2010

K6CrNb15O42 crystallizes in the hexagonal system with a =9.126 (3) Å, c =12.068(3) Å, V =870.4(5) Å2, and space group P62 / mcm, Z =1. The structure was solved using direct method and Fourier Techniques. Of the 829 unique reflections measured by counter techniques, 448 with 1 ≥ 3σ(I) were used in the least‐squares refinement of the model to R =0.034 (Rw =0.044). The structure of K6CrNb15O42 may be described as consisting of corner‐shared and edge‐shared octahedra, the ring units composed of six octahedra of Nb(1) are corner‐shared one another along the c‐axis to form hexagonal column octahedra chains which are connected by K+ and octahedra of Nb(2).
Kinetic study on the ligand exchange reactions between bis(alkylxanthato)palladium(II) and bis(N, N‐dialkyldithiocarbamato)palladium(II) by high‐performance liquid chromatography
Authors: Shen Shi‐Gang , Ding Tian‐Hui , Wang An‐Zhou
Published: September 2010

The rate constants and equilibrium constants of ligand exchange reactions between bis (alkylxanthato)palladium(II), Pd (S2COR)2 (R =Am, n‐Hex, Bz), and bis(N, N‐dialkyldithiocarbamato) palladium(II), Pd(S2CNR2)2 (R =Et, n‐Pr, n‐Bu), in chloroform solution have been determined in a temperature range of 20–50°C by means of high‐performance liquid chromatography. It was found that both the forward and reverse reactions are of second order. All of the equilibrium constants K determined are 10.3±1.0, much greater than the value (K=4) calculated statistically which indicates that the ternary complexes are more stable than the binary complexes. The experimental results revealed that the reaction rate decreases with the increase in the size of R and R1 groups and the latter are more remarkable, consistent with the deduction of steric effect. The activation parameters of the reactions have been calculated. In reaction series (11) and (12) (in the text) the isokinetic temperatures β =390±8 K and β =346 ± 15 K have been observed respectively. A plausible mechanism involving an eight‐membered ring intermediate has been proposed on the basis of experimental results.
Synthesis and structure of the cluster μ3‐sulfido‐μ‐–(diethylphosphorodithioato‐S, S'‐)‐allylthioureocyclo‐tris‐[ (μ‐sulfido)‐χ‐(diethylphosphorodithioato‐S, S')‐molybdenum(IV)], Mo3S4(C4H10O2S2P)4(C4H8N2S)
Authors: Lin Xian‐Ti , Lu Jia‐Xi , Huang Jian‐Quan , Huang Jin‐Ling
Published: September 2010

Title compound, Mr =1273.16, was synthesized by a substitution reaction and its crystal is triclinic belonging to space group P1 with cell parameters: a =13.944(2), b =14.143(7), c =14.233(3) Å, α =77.35(3)°, β =69.94(2)°, γ =63.50(3)°, V=2351(1) Å3, Z=2, Dc =1.799g cm−2. Room temperature, graphite‐filtered Mo Kα radiation (λ =0.71073Å) was used for data collection. μ =14.988 cm−1, F(000) =1280, R=0.051 for 7025 observed reflections. The crystal consists of decrete cluster molecules containing a cluster core [Mo2(μ3‐S)]10+ with three μ‐S, one μ‐dtp(dtp =[S2P(OC2H5)]2‐), three χ‐dtp and one allylthioureo to form a local six‐coordinated sphere around each Mo atom. The bonds of cluster skeleton [Mo3(μ3‐S)(μ‐S)3]4+, MoMo 2.744∼2.766, Mo—(μ2‐S) 2.340∼2.342 and Mo—(μ‐S)2.272∼2.296 Å, are comparable with those found in the related analogues.
Synthesis and structure of an open‐type trinuclear molybdenum cluster compound [Mo3(μ3‐S)(μ‐S)2‐(μ‐OAc)(S2CNC4H8)3(O)2] · 0.5CH2Cl2 · 2H2O
Authors: Lu Shao‐Fang , Huang Zi‐Xiang , Huang Jian‐Quan , Zhang Bin , Huang Jin‐Ling
Published: September 2010

The title compound was prepared by the reaction of Mo3S4(dtp)4(H2O) [dtp =S2P(OEt)2] with NaOAc·3H2O and C4H2NCS2NH4. Crystallographic data: [Mo3(μ‐S)(μ‐S)2(μ‐OAc)‐(S2CNC4H2)3(O)2] · 0.5CH2Cl2 · 2H2O,Mr=980.18, triclinic, space group P1, a =12.360(3), b =16.653(6), c =9.206(2) Å, α =101.97(2), β =108.32 (2), γ =86.14(3)°. V=1759.6(9)Å2, Z =2, Dc =1.85 g/cm2, F(000) =962, μ(Mo Kα) =16.53 cm−1. Final R =0.044 for 4301 reflections with I>3σ (I). This compound may be regarded as a mixed‐valent trinuclear molybdenum cluster {Mo3(V) Mo(V) (μ2‐S) (μ‐S)2‐(μ‐OAc) (S2CNC4H8)3 (O)2}. The Mo—Mo distances are 2.783(1), 2.833(1) and 3.374(2)Å in the Mo3 non‐equilateral triangle and there exist only two Mo—Mo bonds. The cluster was obtained by oxidation and ligand substitution of {Mo2(μ2‐S) (μ‐S)2[μ‐S2P(OEt)2)] [S2P(OEt)2]3 (H2O)}.
Studies on condensed heterocyclic compounds II. Synthesis and antibacterial activity of 3‐(4′‐pyridyl)‐6‐aroylamino/arylamino‐S‐triazolo[3,4‐b]‐1,3,4‐thiadiazoles
Authors: Zhang Zi‐Yi , Chen Xin
Published: September 2010

3‐(4′‐Pyridyl)‐4‐amino‐5‐mercapto‐1,2,4‐triazole (1) reacted with aroyl isothiocyanates 2a‐1 to yield twelve novel 3‐(4′‐pyridyl)‐6‐aroylamino‐S‐triazolo [3,4‐b]‐1,3,4‐thiadiazoles, 4a‐1. Triethylamine was necessary for the condensation of 1 with phenyl isothiocyanate (3) to give 3‐(4′‐ pyridyl)‐6‐phenylamino‐S‐triazolo [3,4‐b]‐1,3,4‐thiadiazole (6). The structures were confirmed by the elemental and spectral analyses. Their antibacterial activity against B. Subtilis, E. Coli, E. aerogenes and S. aureus was observed preliminary.
Studies on the synthesis of amino acids XII. Solid‐liquid phase transfer catalytic dicondensation of 1,4‐diacetyl‐2,5‐piperazinedione with aldehydes
Authors: Du Zheng‐Ming , Zhou Xiao‐Ming , Shi Yao‐Zeng , Hu Hong‐Wen
Published: September 2010

3,6‐Diarylidene‐2,5‐piperazinediones (2) and 3‐alkylidene‐6‐arylidene‐2,5‐piperazinediones (6) were synthesized from diacetyl‐2,5‐piperazinedione (1) under solid‐liquid phase transfer catalytic conditions. 2 could be easily convered to α‐amino acid by reducing with zinc powder and hydrolyzing with concentrated hydrochloric acid. The effect of different phase transfer catalysts and reaction conditions were studied.
The role of 3d orbitals in the bonding of phosphorus compounds
Authors: Li Le‐Min , Xiao Li , Liang Zhen‐Xuan
Published: September 2010

Ab initio LCAO‐MO‐SCF calculations for several typical molecules containing phosphorus have been undertaken to study the role of phosphorus 3d orbitals in the bonding. It is emphasized that the discussion about the 3d orbital participation in bonding should be based on a reasonable choice of basis sets and it seems suitable to choose the atomic orbitals in proper molecular environment as the basis set. As an approximation, the optimized minimal STO‐NG basis sets have been adopted in the present paper. The results obtained well exhibit the model of 3d orbital participation in bonding. It is shown that under the influence of highly electronegative ligands the phosphorus 3d orbitals contract greatly, their energy levels drop considerably, and thus they can effectively participate in bonding. The presence of highly electronegative ligands seems necessary. The contribution of 3d orbitals to bonding is achieved mainly through the concerted formation of σ bonds and p‐d backbonds, though the contribution to σ bonding is minor. The three‐center, four‐electron bond model is only approximately correct. The results of the present paper demonstrate that the model of 3d orbital participation in bonding favoured by experimental chemists is reasonable and possesses sound ground.
Photoelectrochemical behavior, XPS and Auger of n‐In2S3
Authors: Gong Sun‐Quan , Tan Zheng
Published: September 2010

n‐In2S3 has been prepared by CVT method. The photoelectrochemical behavior of n‐In2S3 in a polysulfide redox solution was investigated. It was found that photoetching remarkably increased the fill factor. The maximum quantum efficiency of carrier collection reached 95% after 12h irradiation at 100 mW/cm2 at an applied potential of + 1.2 V. XPS and Auger analysis were carried out for examining surface and bulk concentration. The photoetching effect could be satisfactorily explained.