简介：

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：AF-5wassynthesizedthroughaconvergentmethod.ThekeystepwastheRobinsonannulationusingakeyintermediatepentylvinylketone.

简介：Tris)(η5-cyclopentadienyl-μ-carbonyl-iron)-μ3-nitrosylclusterwasobtainedfromthereactionofcyclopentadienyldicarbonylirondimerwithnitrogenmonoxideinxylene.Theclusterwascharacterizedbyelementalanalyses,IR,MSand1HNMR.Thecrystalstructureof[(η5-C5H5)(μ-CO)Fe]3(μ3-NO).C4H8OwasdeterminedbyX-raydiffractionanalysis.ItcrystallizesintheorthorhombicspacegroupPnma,a=9.053(2),6=10.545(2),c=22.525(4)A,V=2150.3(7)A3,Z=4,Dc=1.68g.cm-3;structuresolutionandrefinementbasedon1141reflectionswithI>3.0(I)(MoKa,A=0.71073A)convergedatR=0.0540.Theinfraredabsorptionbandat1325cm-1oftheμ3-NOinthecluster,whichisredshifted,showsthatμ3-NOisactivated.

简介：(-)-(5R,6S)-6-Acetoxyhexadecan-5-olide1,anaturalmosquitoattractantpheromone,wassynthesizedfromreadilyavailablealdehyde2andcyclopentanone3usingL-proline-catalyzedasymmetricaldolreactionasthekeystep.

简介：TwonewcoenzymeB12analogues,2’,5’-dideoxycytidylcobalamin(2a)and2’,5’-dide-oxyuridinylcobalamin(2b),andtwoothers,2’,5’-dideoxyadenosylcobalamin(2c),and5’-deoxy-thymidylcobalamin(2d)werepreparedbyanimprovedmethod.AllthefouranalogueswereinvestigatedbyUV-visand2D1HNMRspectroscopy.Thecomparisonsanddiscussionabouttheirspectroscopicpropertiesweredone.

简介：(±)-5,5'-Dihydroxy-7,7'-dimethoxy-8,8'-biflavone((±)-l)wasresolvedintoitsopti-callypureformsviatheformationandrecrystallizationofits(2R)-and(2S)-l-(4-toluenesulfonyl)proly-late,andthemethylatedderivativesof(+)-and(-)-lwerealsoprepared.Theabsoluteconfigurationsofallthese8,8'-biflavoneshavebeenconfirmedbytheirCDspectra.

简介：Reactionsofthe6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrilederivative1withα-halo-carbonylcompoundsgavetheortho-substitutedintermediates2a-cwhichwereconvertedintofuro[2,3-b]thiopyrano[4,3-d]pyridines3a-cbyfusionofafuranmoietyunderbasicconditions.Furthercyclizationof3a-cledtoafusionofapyrimidinering,yieldingthetetracyclicproducts6,7and8.Inaddition,condensationof6withvariousaromaticaldehydesaffordedthecorrespondingimines9a,b.Mannichreactionof7gaveproducts10a,b.

简介：在油页岩的反击过程期间形成的CaS在表面水质量上有危险影响。有水的反驳说的油页岩的相互作用由于CaS部件与硫的一个高内容产生高度碱的leachate。在与水的接触描述稳固的钙硫化物的行为的一个理论模型被开发。模型与在溶解行为看变化稳固的CaS什么时候留在答案的大小历久不渝。pH的试验性的大小和离子的集中在25点在没有氧的水里被执行吗？

简介：Fourteennew1-acyl-5-arylbiuretsweresynthesizedbythereactionofarylureaswithacylisocynantes.Thelatterwasobtainedfromacylchlorideandleadcyanateindichloromethane,usingpyridineascatalyst.Thestructuresofcompounds3a-nwereconfirmedbyIR,1HNMRandMSspectra.

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.

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简介：5-Amino-1,10-phenanthrolineandthreetypesofnew5-substituted1,10-phenanthrolinederivativesbydifferentalkylamides,phen-NHCOR[phen=1,10-phenanthrolineR=CH=CH2;(CH2)nBr,n=1,3-5(CH2)nCH3,n=9--14],weresynthesized.Theywerecharacterizedbymeansofelementalanalyses,infraredspectroscopy,protonnuclearmagneticresonancespectroscopy,andmassspectroscopy.Thesenewcompoundsareimportantligandsortheactivematerialsofruthenium(Ⅱ)electrochemiluminescent(ECL)sensors.

简介：ThecatalyticactivityofFe/ZSM-5fortheselectivereductionofNOtoN2withmethaneinthepresenceofexcessO2wasstudied.Fe/ZSM-5catalystswithvariousFeloadingswerepreparedbyimpregnationmethod.ItiswellknownthatmethaneisinactivewhenFe/ZSM-5asthecatalystfortheselectivecatalyticreduction(SCR)ofNOwithmethane.However,thispapershowsthatwhenthecontentofFewasabout0.5%,Fe/ZSM-5showedhighercatalyticactivityandselectivityofmethane,andputforwardmeasurableactivationforCH4isanimportantfactorforthereactionofremovalofNOxwithCH4.

简介：Sulfonylureaherbicideshavebeenwidelyusedbecauseoftheirlowapplicationrates,goodcropselectivitiesandlowmammaliantoxicities.However,somesulfonylureasmightpersistunfavourablyintheenvironmentwithresidualproblems.Inordertolookforecologicallysaferandenvironmentallybenignsulfonylureas,andonkeepingthepyrimidineringbeingmonosubstituted,15novelC5-monosubstitutedbenzenesulfonylureacompoundsweresynthesized.Thestructuresofallthecompoundssynthesizedwereconfirmedbyelementalanalysisand1HNMR.PreliminaryherbicidalactivitiesofthesenewsulfonylureacompoundsweredeterminedbyALSscreening(invitro)andpotbioassayexperiments(invivo).TheherbicidalresultsshowthatsomenovelsulfonylureasarecomparabletocommercialForamsulfuronandMonosulfuron.

简介：Newmethodsfordehydrogenationofsteroidal2,5（10）-dieneswith2,3-dichloro-5,6-dicyano-1,4-benzoquinone（DDQ）orpyridiniumhydrobromideperbromide（PHP,Py·HBr·Br2）toaromaticAringsteroidinquantitativeyieldinshorttimearedescribed.

简介：Thesupramolecularinclusioncompoundofβ-cyclodextrin(β-CD,host)with(η5-cyclopentadienyl)tricarbonylmanganese[MnCp(CO)3,guest]wasobtainedinacrystallinestate.Thehost-guestcompoundisthermallystableanddonotliberatetheguestonheatingat100$invacuum.Itwascharacteriedbyelementalanalysis,1HNMR,differentialscanningthermal(DSC)analysisandTLC.ContinueousvariationplotbyNMRmethodshowsthatβ-CDformed1:1inclusioncompoundwithMnCp(CO)3.Onthebasisof1HNMRspectraandthemodelbuildingwithCoreyPaulingKoltum(CPK)models,themostprobableinclusionmodeisproposed.

简介：参照欧盟玩具安全（2009/48/EC号）指令的要求,应用电感耦合等离子体原子发射光谱法（ICP-AES）测定儿童用品材料中17种元素迁移量.样品主要有儿童玩具、童车、学生用品和儿童家具四大类别.共计测试样品337批,测试样品数为1029个.实验结果表明,部分样品中有铝、钡、镉、铬、铜、铅、锰、锶和锌检出,部分样品中铅、镉迁移量超过欧盟玩具安全新指令限量要求.

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简介：bicyclo[2.2.2]与在C-8和C-9的一枚内酯的戒指，atisine类型C20-diterpenoid碱，辛烷C/D戒指系统成功地被综合，用氧化dearomatization/intramolecularDielsAlder反应。