简介:SYNTHESIS AND 183W NMR CHARACTERIZATION OF P4W30Al4(H2O)2O11220- HETEROPOLYANIONSYNTHESISAND183WNMRCHARACTERIZ?..
简介:Afacilesyntheticroutetotwoseco-eudesmane,4,5-dioxo-10-epi-4,5-seco-γeudesmane(1)and4,5-dioxo-10-epi-4,5-seco-γ-eudesmol(2)from(+)-dihydrocarvonehasbeendescribed.Avoidingexpensivereagents,thishighlyeconomicmethodespeciallysuitsforthesynthesisof4,5-seco-eudesman-typeandophianon-typesesquiterpeneswithadoublebondatposition11and12.
简介:Anovelclassoffulgimide,(Z)-4-oxazolylfulgimide((Z)-1-benzyl-4-isopropylidene-3-[1-(2-aryl-5-methyloxazolyl)ethylidene]tetrahydropyrrole-2,5-dione),wassynthesizedbythereactionof(Z)-4-oxazolylfulgide(4-isopropylidene-3-[1-(2-aryl-5-methyloxazolyl)ethylidene]tetrahydrofuran-2,5-dione)withbenzylamine.Photochromicpropertyof(Z)-4-oxazolylfulgimidewasstudied.Comparedwith(Z)-4-oxazolylfulgide,theabsorptionmaximumofthecoloredformof(Z)-4-oxazolylfulgimideisbathochromic-shifted.Substituentsonthearylringaffecttheabsorptionmaximumoftheopenformandthecoloredformof(Z)-4-oxazolylfulgimide.
简介:Thenon-isothermaldecompositionoflead2,4,6-trinitroresorcinatemonohydrate,Pb(TNR)·H2O,wasinvestigatedbymeansofTG-DTA,DSCandIR.Thethermaldecompositionmechanismandthedissociatedkineticswerealsoinvestigated.ThekineticparameterswereobtainedfromtheanalysisoftheDSCcurvesbyintegralanddifferentialmethods.ThemostprobablekineticmodelfunctionofthedehydrationreactionofPb(TNR)·H2Owassuggestedbythecomparisonofthekineticparameters.
简介:Itiswellknownthatelectrochemicaloxidationofanilinedissolvedinelectrolytesolutionsisaveryusefulmethodforpreparingpolyanilinefilmsonelectrodes’.However,itisverydifficultforthismethodtoprepareauniformmonolayerpolymersincelocalnucleationandgrowthofpolyme...
简介:本文探讨(CH3Li)4中键的作用,通过计算,发现(CH3Li)4分子的面甲基结构比顶甲基结构要稳定;指出Li—Li间的成键作用相当强,约为Li2分子中键作用的40%左右,估计(CH3Li)4中的J7Li-6Li值约为1Hz。
简介:4-(Succinimido)-1-butanesulfonicacidasanefficientandreusableBronstedacidcatalyzedthesynthesisofpyrano[4,3-b]pyranderivativesundersolvent-freeconditions.Thecatalystcanbepreparedbymixingsuccinimideand1,4-butanesultonethatismoresimpleandsaferthanthepreparationofsuccinimidesulfonicacid.Thismethodhastheadvantagesofhighyield,cleanreaction,simplemethodologyandshortreactiontime.Thecatalystcouldberecycledwithoutsignificantlossofactivity.
简介:Anovelsupportedliquidphasefilmcatalyst:SupportedPdCl2-(n-C4H9)4N+Cl-moltensaltswasfoundtobeaneffectivecatalystwithgoodstabilityforselectivehydrodechlorinationofCCl2F2(CFC-12)toitsalternativesCH2F2andCHClF2.AdditionofCoCl2,GaCl3andCuCl2toPdCl2-(n-C4H9)4N+Cl-modifiesthecatalyticperformanceofsupportedmoltensalts.
简介:在水热条件下,制备了一种基于Keggin型多金属氧酸盐的银配合物[Ag(10)(NCA)4(PW9ⅥW3ⅤO(40))(H2O)4].通过元素分析、红外光谱和X-射线单晶衍射方法确定了该配合物的晶体结构.在合成过程中,3-(2-吡啶羧酸)酰胺-吡嗪配体(L)分解成烟酸NCA.结构分析表明:该化合物属于三斜晶系,P1空间群,晶胞参数a=1.18874(9)nm,b=1.24950nm,c=1.41103(10)nm,α=73.712(2)°,β=66.720(2)°,γ=83.467(2)°,V=1.8479(2)nm3,Z=1,R1=0.0731,ωR2=0.1974.配合物中含有一种六核银亚单元[Ag6(NCA)4](2+),不同亚单元间通过配位水的氧原子连接形成一维双链结构,而一维双链进一步通过Ag—N键连接形成二维层状结构,二维层则通过[PW9ⅥW3ⅤO(40)](6-)多阴离子形成最终的三维金属有机框架.标题配合物修饰的碳糊电极对H2O2和KNO2还原有好的电催化活性,而且该配合物对降解亚甲基蓝、罗丹明B分子有较高的光催化效率.
简介:Two-armedneutralanionreceptors(4,5),calix[4]arenesbeatingthioureaandamidebindingsites,werepreparedandexaminedtheiranion-bindingabilitybytheUV-visspectra.Theresultsofnon-linearcurvefittingandJobplotindicatethat4or5forms1:1stoichiometrycomplexwithfluoridebyhydrogenbondinginteractions.Receptors4and5haveanexcellentselectivityforfluoridebuthavenobindingabilitywithacetate,dihydrogenphosphateandthehalogenanions(Cl^-,Br^-,I^-).
简介:Threepairsofnovel2-aryl-3,4,5-trihydroxypiperidines(6–8andtheirenantiomers),thepiperidineanaloguesofthepyrrolidinealkaloidsradicamineAandradicamineB,werepreparedfromsixmemberedcyclicnitronesthroughaconcisetwo-stepprocedure,i.e.,Grignardreagentadditionanddeprotection.Thesenovelpolyhydroxylatedpiperidineiminosugarswereassayedagainst10typesofenzymes.Onlycompound8exhibitedweakinhibition(IC501080mmol/L)againstb-galactosidasefromratintestinallactases.
简介:Anovelflower-likehydratedmagnesiumcarbonatehydroxide,Mg_5(CO_3)_4(OH)_2·4H_2O,withmicro-structurecomposedofindividualthinnano-sheetswassynthesizedusingafacilesolutionroutewithouttheuseoftemplateororganicsurfactant.Reactiontimehasanimportanteffectonthefinalmorphologyoftheproduct.Themicro-structureandmorphologyofMg_5(CO_3)_4(OH)_2·4H_2OwerecharacterizedbymeansofX-raydiffractometry(XRD),field-emissionscanningelectronmicroscopy(FE-SEM).Brunauer-Emmett-Teller(BET)surfaceareasofthesampleswerealsomeasured.Theprobableformationmechanismofflower-likemicro-structurewasdiscussed.ItwasfoundthatMg_5(CO_3)_4(OH)_2·4H_2Owithflower-likemicro-structurewasanovelandefficientcatalystforthesynthesisofdiphenylcarbonate(DPC)bytransesterificationofdimethylcarbonate(DMC)withphenol.