简介：Synthesisofinorganicnanostructureswithspecificsizeandwelldefinedmorphologieshasattractedconsiderableattentionduetotheirsuperiorelectrical,optical,magnetic,andchemical

简介：利用Gaussian-94计算程序中的B3LYP方法,在6-311+G(2d)6d基组下,对Si5,Si5H3,Si5H6,Si5Li3和Si5Na3原子簇的几何结构进行优化和频率计算.结果表明,Si5原子簇中最稳定的具有D3h对称性的结构中,位于同一平面上的3个Si原子确实具有剩余的成键能力,可以与3个H,Li,Na原子和6个H原子形成稳定的化合物.研究还发现,虽然H,Li和Na都属同一主族,但它们与Si5原子簇中Si原子的键连方式却不同,而且它们的加入,对Si5原子簇的'三角双锥'结构也有不同的影响.

简介：从价格低廉的皂素为起始原料，通过一系列化学反应，合成了不同结构的环氧甾体类药物中间体．以波谱方法进行结构表征，同时对环氧甾体化合物5，6-环氧孕甾-16-烯-20-酮-3β-乙酸酯的单晶进行了结构分析．

简介：建立了计算多环芳烃水中溶解度的数学表达式,用量子化学方法计算了7个多环芳烃的水中溶解度,计算结果与实验测定结果相符合.多环芳烃处于水体内体系状态能量愈高,其溶解度愈小,多环芳烃中的碳氢基团越多,溶解度越小.此时体系中的溶质呈单分子态,而不是聚集态.

简介：采用四溴邻二甲苯脱卤法得到苯并环丁烯(BCB)单体.利用BCB的芳香性,将其溴化后,制成格氏试剂,倒入干冰中,与之反应,得到4-羧基-BCB.将所得的4-羧基-BCB与氯化亚砜回流,活化为酰氯,与聚乙烯醇(PVA)反应,BCB结构单元被引入到聚合物的支链上,由此得到苯并环丁烯聚合物.并对该聚合物的结构进行了表征.

简介：TwopossiblereactionmechanismsofVS~+(~3∑~-,~1Γ)withCOinthegasphasehavebeenstudiedbyusingB3LYP/TZVPandCCSD(T)/6-311+G(3dr,3pd)methods:theO/Sexchangereaction(VS~++CO→VO~++CS)andtheS-transferreaction(VS~++CO→V~++COS).Thetworeactionsproceedviatwo-stepandone-stepmechanism,respectively.ThebarriersofthetripletandsingletPESsare30.6and50.9kcal/mol,respectively,forO/Sexchangereactionand7.3and50.2kcal/mol,respectively,fortheS-transferreaction.Theresultsindicatethatthetripletgroundstatereactionismorefavorable,andtheS-transferreactionismorefavorablethantheO/Sexchangereaction,whichisingoodagreementwiththeexperimentalobservation.

简介：FurfuralinaqueoussolutionwastreatedbyUV/O3method.Theresultsshowthattheremovalrateoffurfuralisseverelyenhancedandthesynergismphenomenonappearswhenultravioletandozonearepresenttogether.TheinfluencesofexperimentalparameterssuchaspH,theintensityoflightandthenegative-positiveionsonfurfuraldegradationwereinvestigated.Theresultsindicatethatfurfural(300mg/L)isalmostcompletelydegradedafter3hundertheoptimumconditions.TheintermediateinthefurfuraldegradationwascharacterizedbyGC-MSandIRspectrumandthedegradationmechanismoffurfuralbyUV/O3technologywasproposed.

简介：Thetitlecompounds5a-5cwerepreparedviathereactionofmethyl2-perfluoroal-kynoates(4)withmethyl5-oxo-4-(triphenylphosphoranylidene)hex-2-enoate(3),whichwasobtainedfromthereactionofmethylpropynate(2)withacetylmethylenetriphenylphosphorane(1)at-5-0℃.IntramoleculareliminationofPh3POtookplacewhencompound5washeatedinaqueousmethanolat115-120℃insealedtube,yieldingdimethyl2-trifluoromethyl-4-methylisophthalate(6a)from5aandmethyl5-acetyl-4-hydroxy-2-heptafluoropropanylbenzoate(6b)from5b,respectively.Thestructuresofcompounds5,6aand6bwereconfirmedbyIR,MS,1HNMR,19FNMRand13CNMRspectroscopyandelementalanalyses.Rectionmechanismsfortheformationofcompounds5,6aand6bwereproposed.

简介：Erbium,Ytterbium-codopedZrO2nanoparticles(ZrO2∶Er3+,Yb3+)werepreparedbythesol-emulsion-geltechnique.Thepurposeofthepresentstudyistheapplicationofupconversionphosphorinthebiologicallabel.Inordertomakeoutthemechanismofupconversionunder980nmexcitationthe488nmpumpwasused.Theinfluenceoftemperatureonthecrystallitephasewasstudied.TheresultsconfirmtheupconvertedmechanisminZrO2∶Er3+,Yb3+nanocrystalsisduetoanenergytransferupconversion(ETU).

简介：(-)-cis-1,3-Dibenzyl-hexahydrofuro[3,4-d]imidazole-2,4-dionewaspreparedbyanewsynthesismethodfrommesodicarboxylicacidanddehydroabietylaminebyasymmetricreductioningoodyieldwithupto91.6%e.e.value.

简介：Themonomericcobalt-phosphite-thiolatocomplex[Co(mpt)2{P(OCH3)3}2]BF4(Hmpt=2-mercaptothiazoline)hasbeenpreparedandcharacterizedbyX-raycrystallography.ThecomplexcrystallizesinthemonoclinicspacegroupC2/cwitha=0.8078(5),b=2.6020(18),c=1.2191(7)nm,β=99.38(1)°,V=2.528(3)nm3,andZ=4.Thestructurecomprisesdiscretecations[Co(mpt)2{P(OCH3)3}2.]+andanionsBF4-,inwhichthecobalt(Ⅲ)atomiscoordinatedtotwochelatempt-andtwoas-orientedmonodentateP(OCH3)3ligandsinahighlydistortedoctahedralgeometry.ThemostdistortedanglesareS(2)-Co(1)-S(2a)of162.23(10)°andN(1)-Co(1)-S(2)of71.47(13)°,thelatteriscausedbythegeometricconstraintofthebidentateligandmpt-.CyclicvoltammetryhasbeenusedtostudytheelectrochemicalbehaviorofthetitlecomplexontheRelectrodeinMeCNsolutionwith0.1mol·L-1ofBun4NBF4aselectrolyte.TheresultsindicatethatthetitlecomplexisunstableinMeCN.

简介：采用CBS-QB3方法构建了丙烯酸甲酯（CH_2=CHCOOCH_3）与O_3反应体系的势能剖面并在此基础上利用经典过渡态理论（TST）和Wigner矫正模型计算了标题反应在200K～1200K温度区间内的速率常数kTST/W.研究结果表明,CH_2=CHCOOCH）3与O）3反应首先经过渡态生成一个稳定的五元环中间体,然后按断键位置不同,分别生成产物P1（CH_3OCOCHO＋CH_2O_2）和P2（CH）3OCOCHOO＋HCHO）.此外,速率常数结果显示,在计算温度范围内,标题反应速率常数呈正温度系数效应.294K时,CH_2=CHCOOCH_3与O_3反应速率常数为1.76×10^（-18）cm^3·molecule^（-1）·s^（-1）,与所测实验值（0.95±0.07）×10^（-18）cm^3·molecule^（-1）·s^（-1）非常接近.

简介：Treatmentof4-amino-3-(1-aryl-5-methyl-1,2,3-triazol-4-yl)-5-mercapto-1,2,4-triazoles/2-amino-5-(1-aryl-5-methyl-1,2,3-triazole-4-yl)-1,3,4-thiadiazoleswithbenzaldehyde,acetoneandω-bromoacetophenonewastestedandcompared.ThetitlecompoundsSchiffbases,amides,imidazolo[2,1-b]-1,3,4-thiadiazolesand7H-s-triazolo[3,4-b]-1,3,4-thiadiazineshavebeenconfirmedbyelementalanalyses,^1HNMR,IRandMSspectra.AllthecompoundshavealsobeenscreenedfortheirantibacterialactivitiesagainstB.subtilis,S.aureusandE.coli.

简介：标题化合物C26H26O5以2,3-萘二甲醛和5-甲基-1,3-环己二酮为原料,在醋酸溶剂中,室温下经搅拌多组分一锅法合成得到.其结构通过单晶X-射线衍射法确定,晶体属单斜晶系,空间群P21,相对分子质量Mr=418.47,晶胞参数a=0.99004（8）nm,b=1.09098（9）nm,c=1.04246（11）nm,V=1.08753（17）nm3,Z=2,晶胞密度Dc=1.278g/cm3,吸收系数μ=0.088mm-1,单胞中电子的数目F（000）=444.晶体结构用直接法解出,经全矩阵最小二乘法对原子参数进行修正,最终的偏离因子为R1=0.0533,wR2=0.1293.在晶体结构中新形成的吡喃环为半椅式构象,而茚中五元环则为信封式构象.

简介：以1，3-丁二醇、柠檬酸为原料，设计、合成了以1，3-丁二醇为核心的柠檬酸-1，3．丁二醇-柠檬酸（cBc）爪状物小分子；再用酯化反应依次与带有功能化集团的硬酯酸、十六醇接枝合成了多元酯类爪形大分子柠檬酸-1，3-丁二醇-柠檬酸-硬酯酸-十六醇（CBC-SH）．采用核磁共振、红外光谱对合成的两种化合物进行了结构表征，表明合成的CBC和CBC-SH与所设计的分子结构相吻合．元素分析确定了CBC和CBC-SH的化学组成依次为C16H22O14和C98H184O15．合成的CBC-SH溶于非极性的有机溶剂，不溶于水．将CBC-SH按600μg／g的加剂量添加到不同的轻柴油中，柴油的冷滤点可降低6℃．

简介：ＲＥＡＣＴＩＯＮＯＦ　３，７－ＤＩＮＩＴＲＯＤＩＢＥＮＺＯＢＲＯＭＯＬＩＵＭＢＩＳＵＬＦＡＴＥＷＩＴＨＳＯＭＥ　ＮＵＣＬＥＯＰＨＩＬＥＳＺｉＪｉｅＨＯＵ；ＨｕｅｉＺＨＡＮＧａｎｄＺｉａｎＨｕａＺＨＡＮＧ（ＩｎｓｔｉｔｕｔｅｏｆＯｒｇａｎｉｃＣｈｅｍｉ...

简介：Theenzymaticresolutionofracemicmethyl3-phenylglycidatewasinvestigated.Itwasfoundthatthehydrolysisrateof(2S,3R)-enantiomerwasfasterthanthatof(2R,3S)-enantiomerbyanewlipase.Atoptimalcondition96%of(2R,3S)-methylphenylglycidatewitheeof100%wasrecoveredfromtheracemicmixture.

简介：

简介：Theperovskite-typeAgTaO3crystalswerepreparedbymildhydrothermalmethodanddeterminedbypowderX-raydiffraction.RietveldrefinementindicatesthatAgTaO3crystallizedinanorthorhombicsystemwiththespacegroupPcmn.Thelatticeparametersarea=5.5822(1)nm,b=7.8522(2)nmandc=5.5347(1)nm,withα=β=γ=90.0o.Thecompoundwascharacterizedbyscanningelectronmicroscopy(SEM),X-rayphotoelectronspectroscopy(XPS),highresolutiontransmissionelectronmicroscopy(HR-TEM)andUV-Visdiffusereflectancespectrometry(UV-VisDRS).ThephotocatalyticactivityofAgTaO3powderwasevaluatedbythedegradationofCongoredunderUV-lightirradiation.Theresultshowsthatthetitledcompoundhasahighphotocatalyticactivityatroomtemperatureandpotentialapplicationinphotocatalysis.

简介：采用溶胶凝胶法合成了稀土离子Er^3＋-Yb^3＋共掺杂的纳米TiO2晶体粉末，利用XRD，UV-VIS吸收光谱及上转换发射光谱对其结构和光学特性进行了表征．以致病性嗜水气单胞菌为实验菌株，以980nm激光为激发光源，考察了室温下Er^3＋-Yb^3＋共掺杂纳米TiO2的光催化杀菌性能．结果表明，稀土离子掺杂的纳米TiO2可以通过上转换发光的途径增加TiO2对可见光的利用率，从而实现TiO2在可见光和近红外光范围的光催化氧化杀菌作用．