Chemical Research in Chinese Universities最新文献

{"title":"Thermal Decomposition of Ammonium 3-Nitro-1,2,4-triazol-5-onate Monohydrate","authors":"Ji-zhen LI ,&nbsp;Xue-zhong FAN ,&nbsp;Jiao-qiang ZHANG ,&nbsp;Guo-fang ZHANG ,&nbsp;Bo-zhou WANG","doi":"10.1016/S1005-9040(09)60028-3","DOIUrl":"10.1016/S1005-9040(09)60028-3","url":null,"abstract":"<div><p>The thermal decomposition of ammonium 3-nitro-1,2,4-triazol-5-onate monohydrate[NH₄(NTO)·H₂O] was studied by means of thermal analysis-MS coupling and the combination technique of <em>in situ</em> thermolysis cell with rapid-scan Fourier transform infrared spectroscopy. The results show that there are two endothermic steps and one exothermic step in the decomposition process of NH₄(NTO)·H₂O. The detected gas products consist of NH₃, H₂O, N₂, CO₂, CO, and NO₂.</p></div>","PeriodicalId":9785,"journal":{"name":"Chemical Research in Chinese Universities","volume":"24 6","pages":"Pages 786-789"},"PeriodicalIF":3.1,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-9040(09)60028-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56328985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation and Magnetic Property of La0.7Sr0.3MnO3 Nanorod by Combination Sol-Gel with Molten Salt","authors":"Shu-yan QI,&nbsp;Jing FENG,&nbsp;Xiao-dong XU,&nbsp;Jing-ping WANG,&nbsp;Xiang-yu HOU,&nbsp;Mi-lin ZHANG","doi":"10.1016/S1005-9040(09)60003-9","DOIUrl":"10.1016/S1005-9040(09)60003-9","url":null,"abstract":"<div><p>La_0.7Sr_0.3MnO₃(LSMO) nanorods were synthesized by a method combining sol-gel with molten salts at 950 °C for 10 h, which employed KCl+NaCl(mass ratio 4:1) as eutectic molten salts. The morphologies and magnetic properties of the resulting LSMO nanorods were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), and vibrating sample magnetometer(VSM) measurements. It was found that the obtained perovskite manganite LSMO was a uniform nanorod with a diameter of about 50 nm and a length of longer than 500 nm. The Curie temperature(<em>T_c</em>) of the LSMO nanorod used here was 262 K, much lower than that of bulky single crystal LSMO(360 K). The low Curie temperature might be a result of the great disorder near the grain boundary, which could be observed clearly from the TEM picture.</p></div>","PeriodicalId":9785,"journal":{"name":"Chemical Research in Chinese Universities","volume":"24 6","pages":"Pages 672-674"},"PeriodicalIF":3.1,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-9040(09)60003-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56328660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fabrication of Poly(4-vinylpyridine) Nanofiber and Fluorescent Poly(4-vinylpyridine)/Porphyrin Nanofiber by Electrospinning","authors":"Yan SONG ,&nbsp;Nai-qian ZHAN ,&nbsp;Miao YU ,&nbsp;Qing-biao YANG ,&nbsp;Chao-qun ZHANG ,&nbsp;Heng-guo WANG ,&nbsp;Yao-xian LI","doi":"10.1016/S1005-9040(09)60014-3","DOIUrl":"10.1016/S1005-9040(09)60014-3","url":null,"abstract":"<div><p>Poly(4-vinylpyridine)(P4-VP) nanofiber and fluoresent poly(4-vinylpyridine)/porphyrin(P4-VP/TPPA) nanofiber were respectively prepared by electrospinning. The effect of the concentration of P4-VP/dimethylformamide (DMF) electrospinning solutions on the morphology of P4-VP nanofiber was investigated and it was found that the average diameter of the nanofiber of P4-VP/DMF increased with the increase of the concentration of the spinning solution. After the addition of TPPA to the P4-VP/DMF spinning solution, the diameter of P4-VP/TPPA nanofiber became even due to the increase of the conductivity of the P4-VP/DMF-TPPA solution. The photoluminescent(PL) spectral analysis indicates that the emission peak position of P4-VP/TPPA nanofiber is almost the same as that of pure TPPA at about 650 nm without peak shift, and when it was stored for 20 days, the emission peak of P4-VP/TPPA nanofiber is also at 650 nm, indicating that the fluorescent property of P4-VP/TPPA nanofiber is stable. Fourier-transform infrared(FTIR) spectrum confirms the chemical composition of the resulting P4-VP/TPPA composite nanofiber.</p></div>","PeriodicalId":9785,"journal":{"name":"Chemical Research in Chinese Universities","volume":"24 6","pages":"Pages 722-725"},"PeriodicalIF":3.1,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-9040(09)60014-3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56328799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Asymmetric Synthesis of (R)- and (S)-Moprolol","authors":"Zhao-yang WANG ,&nbsp;Yan WANG ,&nbsp;Li-wen SUN ,&nbsp;Jin-tao ZHU","doi":"10.1016/S1005-9040(09)60020-9","DOIUrl":"10.1016/S1005-9040(09)60020-9","url":null,"abstract":"<div><p>A simple and effective procedure for the enantioselective synthesis of (<em>R</em>)- and (<em>S</em>)-Moprolol was described. The key step was the asymmetric synthesis of enantiopure (<em>R</em>)- and (<em>S</em>)-guaifenesin, which were synthesized from enantioenriched (<em>R</em>)-3-chloro-1,2-propanediol and (<em>S</em>)-epichlorohydrin <em>via</em> kinetics of hydrolysis resolution of racemic epichlorohydrin by chiral Salen-Co^III complex. The <em>e.e.</em> values of both the optical compounds were above 98%, and the chemical structures of the target compounds were confirmed by ¹H NMR, ¹³C NMR, IR, and MS.</p></div>","PeriodicalId":9785,"journal":{"name":"Chemical Research in Chinese Universities","volume":"24 6","pages":"Pages 747-751"},"PeriodicalIF":3.1,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-9040(09)60020-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56328876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determination of Acetonitrile Volume Fraction in Mobile Phase by HPLC","authors":"Yi WU ,&nbsp;Zhi-wu WANG ,&nbsp;Jing-kai GU ,&nbsp;Ying-wu WANG","doi":"10.1016/S1005-9040(09)60008-8","DOIUrl":"10.1016/S1005-9040(09)60008-8","url":null,"abstract":"<div><p>This paper reports the development and validation of an assay for the determination of acetonitrile in the recycled mobile phase using high performance liquid chromatography(HPLC). The method is based on that the retention in reversed-phase liquid chromatography increases with decreasing concentration of organic phase in the mobile phase. The natural logarithm of the capacity ratio for a given solute is linearly related to the volume fraction of the organic modifier in the mobile phase. For dimethylphthalate and diethylphthalate, the linearity range is 30%–60%, and for biphenyl and terphenyl, the range is 60%–95%. Precision values(RSD) were both &lt;1% and the accuracy(RE) was in the range of ±1%. The assay was successfully applied to the determination of acetonitrile concentration of recycled mobile phase after the distillation of the column eluent in our laboratory.</p></div>","PeriodicalId":9785,"journal":{"name":"Chemical Research in Chinese Universities","volume":"24 6","pages":"Pages 694-696"},"PeriodicalIF":3.1,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-9040(09)60008-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56328717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantitative Analysis of Berberine in Processed Coptis by Near-Infrared Diffuse Reflectance Spectroscopy","authors":"Yong ZHANG ,&nbsp;Yun-fei XIE ,&nbsp;Feng-rui SONG ,&nbsp;Zhi-qiang LIU ,&nbsp;Qian CONG ,&nbsp;Bing ZHAO","doi":"10.1016/S1005-9040(09)60013-1","DOIUrl":"10.1016/S1005-9040(09)60013-1","url":null,"abstract":"<div><p>The near-infrared(NIR) diffuse reflectance spectroscopy was used to study the content of Berberine in the processed Coptis. The allocated proportions of Coptis to ginger, yellow liquor or Evodia rutaecarpa changed according to the results of orthogonal design as well as the temperature. For as withdrawing the full and effective information from the spectral data as possible, the spectral data was preprocessed through first derivative and multiplicative scatter correction(MSC) according to the optimization results of different preprocessing methods. Firstly, the model was established by partial least squares(PLS); the coefficient of determination (<em>R</em>²) of the prediction was 0.839, the root mean squared error of prediction(RMSEP) was 0.1422, and the mean relative error(RME) was 0.0276. Secondly, for reducing the dimension and removing noise, the spectral variables were highly effectively compressed <em>via</em> the wavelet transformation(WT) technology and the Haar wavelet was selected to decompose the spectral signals. After the wavelet coefficients from WT were input into the artificial neural network(ANN) instead of the spectra signal, the quantitative analysis model of Berberine in processed Coptis was established. The <em>R</em>² of the model was 0.9153, the RMSEP was 0.0444, and the RME was 0.0091. The values of appraisal index, namely <em>R</em>², RMSECV, and RME, indicate that the generalization ability and prediction precision of ANN are superior to those of PLS. The overall results show that NIR spectroscopy combined with ANN can be efficiently utilized for the rapid and accurate analysis of routine chemical compositions in Coptis. Accordingly, the result can provide technical support for the further analysis of Berberine and other components in processed Coptis. Simultaneously, the research can also offer the foundation of quantitative analysis of other NIR application.</p></div>","PeriodicalId":9785,"journal":{"name":"Chemical Research in Chinese Universities","volume":"24 6","pages":"Pages 717-721"},"PeriodicalIF":3.1,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-9040(09)60013-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56328789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis of Heterocycle Compounds Containing Two Pyridazinone Units","authors":"Bing-wei XIN","doi":"10.1016/S1005-9040(09)60018-0","DOIUrl":"10.1016/S1005-9040(09)60018-0","url":null,"abstract":"<div><p>Four novel compounds containing two pyridazinone units attached to one benzene or pyridine ring, protected and deprotected 1,5-di[3(<em>2H</em>)-pyridazinon-6-yl]benzene and 2,6-di[3(<em>2H</em>)-pyridazinon-6-yl]pyridine were synthesized in eight steps, which provided a useful method for the preparation of pyridazinone derivatives <em>via</em> the Stetter and cyclization reactions. Their structures were characterized by ¹H NMR, ¹³C NMR, and HRMS.</p></div>","PeriodicalId":9785,"journal":{"name":"Chemical Research in Chinese Universities","volume":"24 6","pages":"Pages 739-742"},"PeriodicalIF":3.1,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-9040(09)60018-0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56328853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inhibition Mechanism of Cholinesterases by Carbamate: A Theoretical Study","authors":"Yuan YAO,&nbsp;Ze-sheng LI","doi":"10.1016/S1005-9040(09)60026-X","DOIUrl":"10.1016/S1005-9040(09)60026-X","url":null,"abstract":"<div><p>The density functional theory at the B3LYP/6-311 G(<em>d, p</em>) level was applied to exploring the inhibition mechanism of cholinesterases by carbamate. The results indicate that the inhibition reactions with or without the catalytic effect of the catalytic triad in cholinesterases underwent a two-step addition-elimination mechanism, which is in good agreement with the proposed mechanism. The solvent has a strong effect on the inhibition reactions and the reaction with the catalytic triad in the solvent phase is close to the real reaction under biological condition.</p></div>","PeriodicalId":9785,"journal":{"name":"Chemical Research in Chinese Universities","volume":"24 6","pages":"Pages 778-781"},"PeriodicalIF":3.1,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-9040(09)60026-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56328959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regioselective Deprotection of 1,3-Dibenzyl-5-(N,N-dimethylamino)-6-phenylethyluracil","authors":"A-min LI ,&nbsp;Xiao-wei WANG ,&nbsp;Zhi-li ZHANG ,&nbsp;Zhi-jian CHENG ,&nbsp;Jun-yi LIU","doi":"10.1016/S1005-9040(09)60017-9","DOIUrl":"10.1016/S1005-9040(09)60017-9","url":null,"abstract":"<div><p>The deprotection of 1,3-dibenzyl-5-(<em>N,N</em>-dimethylamino)-6-phenyl-ethyluracil I was investigated. A practical, regioselective N₃ deprotection of compound I was performed with excellent yield using cyclohexene as a hydrogen donor.</p></div>","PeriodicalId":9785,"journal":{"name":"Chemical Research in Chinese Universities","volume":"24 6","pages":"Pages 735-738"},"PeriodicalIF":3.1,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-9040(09)60017-9","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56328838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation of Nicotinic Acid from Oxidation of 3-Picoline with Oxygen Under Catalysis of T(o-Cl)PPMn","authors":"Jin-quan BAI,&nbsp;Qi-chang WANG,&nbsp;Yun HU,&nbsp;Feng-yan GUO","doi":"10.1016/S1005-9040(09)60019-2","DOIUrl":"10.1016/S1005-9040(09)60019-2","url":null,"abstract":"<div><p>The oxidation of 3-picoline to nicotinic acid took place efficiently in an ethanol solution with O₂ as the oxidant under the catalysis of T(<em>o</em>-Cl)PPMn at 40—150 °C and 0.5—3.0 MPa oxygen pressure. The influences of temperature, oxygen pressure, reaction time, concentration of 3-picoline, concentration of sodium hydroxide, and concentration of T(<em>o</em>-Cl)PPMn catalyst, <em>etc.</em> on the production of nicotinic acid were investigated. The results show that T(<em>o</em>-Cl)PPMn presented excellent catalytic activity in the oxidation of 3-picoline to nicotinic acid and the yield of nicotinic acid varied greatly with the reaction temperature, oxygen pressure, T(<em>o</em>-Cl)PPMn concentration, <em>etc</em>.</p></div>","PeriodicalId":9785,"journal":{"name":"Chemical Research in Chinese Universities","volume":"24 6","pages":"Pages 743-746"},"PeriodicalIF":3.1,"publicationDate":"2008-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S1005-9040(09)60019-2","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"56328865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}