简介:Anefficientandenvironmentallyfriendlyprocedurefortheone-potsynthesisoftetrahydropyrimidinonesfromaldehydes,β-diketonesandurea/thioureabyusingmagnesiumbromideasaninexpensiveandeasilyavailablecatalystundersolvent-freeconditionswasdescribed.ComparedwiththeclassicalBiginellireactionconditions,thisnewmethodhastheadvantageofgoodtoexcellentyields(74%-94%)andshortreactiontime(45-90min).ThestructureoftheBiginellireactionproductfromβ-diketone,salicylaldehydeandureahasbeenproposedtopossessanoxygen-bridgebycyclization(intramolecularMichael-addition).
简介:Theadsorptioncapabilityofloamsoilfornano-TiO2affectedbytheamountandintensityofleachedwaterhasbeeninvestigatedbysimulatingthenaturalrainfallprocessundertheleachingcondition.Theresultsshowthattheamountandtheintensityofleachedwateraretwoimportantfactorsaffectingtheadsorptioncapabilityofloamsoilfornano-TiO2.Theresultsindicatethatthedepthoftheloamsoilcontainingamaximalamountofnano-TiO2isproportionaltotheamountofleachedwater,whileitisinverselyproportionaltotheintensityofleachedwater,ataconstantamountoftheleachedwater.Itwasalsofoundthattheadsorptioncapabilityofsoilsfornano-TiO2canbeimprovedbyaddingothermaterials,suchasdissolvedorganicmatter(DOM),bentoniteandstraw.ItwasfoundthatDOMisthebestsorbentforimprovingtheadsorptioncapabilityofloamsoilfornano-TiO2,followedbybentonite,whilestrawisnotsuitableforthemodificationofloamsoil.Theimprovementofadsorptioncapabilityofloamsoildependsontheamountoftheseadditives.Nano-TiO2canbeeffectivelyadsorbedonthesurfacelayerofloamsoilcontaininganappropriateamountofadditive.
简介:忍受2,6二度(imino)的一系列钴建筑群含苯氧基的ligands,LCoCl2[L=2,6-(ArNCH)2CH3C6H2OH]被ligand2,6二度(imino)的反应综合有钴二氯化物的相等的鼹鼠的酚,和这些建筑群被元素的分析描绘,1HNMR,MS和红外系列。一建筑群的结构被单个水晶X光检查衍射分析决定。
简介:InT12SO4+Na2SO4+di(2-ethylhexyl)dithiophosphoricacid+n-CsH18+watersystem,theT1^+equilibriummolalitiesweremeasuredationicstrengthfrom0.1to2.0mol·kg^-1containingNa2SO4assupportingelectrolyteinaqueousphaseandatconstantmolalityofextractantattemperaturesfrom278.15to303.15Kinorganicphase.ThestandardextractionconstantsK^0atvarioustemperatureswereobtainedbymethodsofextrapolationandpolynomialapproximation.Thermodynamicquantitiesfortheextractionprocesswerecalculated.
简介:Theaggregationbehaviorandstructureofhydrophobicallymodifiedblockcopolymersofacrylamideand2-phenoxylethylacrylatewereinvestigatedbyviscometry,1HNMRrelaxation,2DNOESY,fluorescenceanddynamiclightscattering.Itwasfoundthattheaggregationbehaviorwasstronglydependentontheconcentrationofpolymersolutionandthehydrophobecontents.Withvaryingconcentrationfrom2.0,6.0,8.0to12.0g/L,thereweredifferentaggregatemorphologiesdistributedinaqueoussolutions,suchasmonopolymerchain,micelle-likeaggregate,multi-micelleaggregateandcross-linkednetwork.Accordingtothemodelofaggregation,itcangiveareasonableexplanationonthelargemagnitudeenhancementofviscositywiththeincreasingofpolymerconcentration.Additionaldataof2DNOESYandfluorescenceshowthatthecopolymerwithhigherhydrophobecontent(molarfraction≥1%)islikelytoformintra-molecularassociation.
简介:Thenon-isothermaldecompositionoflead2,4,6-trinitroresorcinatemonohydrate,Pb(TNR)·H2O,wasinvestigatedbymeansofTG-DTA,DSCandIR.Thethermaldecompositionmechanismandthedissociatedkineticswerealsoinvestigated.ThekineticparameterswereobtainedfromtheanalysisoftheDSCcurvesbyintegralanddifferentialmethods.ThemostprobablekineticmodelfunctionofthedehydrationreactionofPb(TNR)·H2Owassuggestedbythecomparisonofthekineticparameters.
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简介:Inthisletter,Fe2O3UFP(UltrafineParticles)hydrosolandorganosolwithhighthirdorderopticalnonlinearsusceptibility(3)havebeenreportedforthefirsttime.ThesurfacialmodificationofFe2O3UFPwithdodecylbenzenesulfonateions(DBS)canenhancethenonlinearopticalresponsethroughinterfacialconfinementofelectronmotion.Theinvolvedmechanismisdiscussed.
简介:Novelsulfur-containingcompounds(3a–3c,4a–4c)wereobtainedinethanolwith1,3-diphenyl-2-propanoneasthestartingmaterial.Theadvantagesofthisprocedureweremildreactionconditions,simpleprotocol,andhighyields.ThestructuresoftheproductswerecharacterizedbyIR,1HNMR,MSandelementaryanalysis.Thecrystalofthenewcompound4abelongstomonoclinic,spacegroupC2witha=18.727(3),b=6.5179(9),c=13.7576(18),b=131.0610(10)°,V=1266.2(3)A3,Z=2,Dc=2.136g/cm3,μ=1.078mm-1,F(000)=843,R=0.0490andwR=0.1247for3211observedreflectionwithI>2δ(I).X-rayanalysisrevealsthatthemoleculeisnotsymmetrical,themolecularstructureisstabilizedbyweakp–pstackinginteractions,andnoclassicalhydrogenbondscanbeobserved.
简介:采用密度泛函B3LYP/6-311G(d,p)方法对CH3F与C2H3的反应体系进行了理论研究,获得了反应的势能面信息及可能的微观机理.在QCISD(T)/6-311++G(d,p)水平上精确计算了各反应物种的单点能.结果表明,除抽提氢反应外,标题反应还存在抽提氟(R1)、消氟化氢(R2)、消氢(R3)和自由基形成(R4)四类反应.在QCISD(T)/6-311++G(d,p)//B3LYP/6-311G(d,p)水平上,R1,R2,R3和R4反应的能垒分别是163.9,152.2,209.8和224.2kJ·mol-1,相应反应能为-56.6,-164.3,-2.7和-156.0kJ·mol-1,所有反应均放热,为热力学允许的反应.
简介:采用HF/6-31G*方法优化分子构型,在此基础上用CPHF方法系统地研究了多种基团取代的2-苯基苯并咪唑衍生物的二阶非线性光学系数βvec,并对βvec的影响因素进行了探讨,为进一步设计综合性能优良的有机非线性光学材料提供理论指导.
简介:采用CCSD(T)/aug-cc-pVTZ//MP2/aug-cc-pVTZ方法构建了HO2+NO反应的单、三重态反应势能剖面.研究结果表明,标题反应在单、三重态均存在3条反应通道,分别经抽氧、加成和抽氢反应生成产物NO2+OH、HNO3和HNO+O2.其中抽氧、加成反应的优势通道发生在单重态势能面上(通道R1和R2),而抽氢的优势通道则发生在三重态势能面上(通道R6).利用经典过渡态理论(TST)并结合Wigner矫正模型在200K1500K温度范围内计算了优势通道R1,R2和R6的速率常数kTST/W.结果显示,在计算温度范围内抽氧、加成反应的通道R1和R2始终存在竞争,且抽氢反应通道R6在高温区500K1500K竞争作用也逐渐显现,但抽氧通道R1分支比始终大于81%,具有绝对优势.
简介:Tetrabutylammoniumorpotassiumsaltsoforganometalllicderivativesoflacunarypolyanion(RM)3P2W15O59^n-(RM=CpTi,CpZr,C4H7O2SnorC5H9O2Sn)havebeenpreparedandstructurallycharacterizedbyelementalanalysis,IR,UV-Vis,^1HNMRand^183WNMRspectroscopies.Thetitlecomplexesexhibitantitumoractivityinvitro.