简介：Asymmetrichydrisilylationcatalyzedbypolymericthiazolidinerhodiumcatalystswasconducted.Almostthesameopticalyieldshavebeenobtainedwhencomb-shapedpolymericligandsandtheircorrespondingmonomercomplexedrhodiumcataltystswereusedtoasymmetrichydrosilylationofacetophenone.Opticalyieldofchiral1-methylbenzylalcoholreachesashighas71.5%.Temperaturedependenceofenantioselectivehydrosilylationofacetophenonewasdiscussed.

简介：AC2-symmetricalaryldiphosphitederivedfromchiralbinaphtholwaspreparedanditsrhodiumcomplexwasusedascatalystsintheasymmetrichydroformylationofolefins.Highcatalyticactivityandgoodregioselectivitywereobserved.Upto31.2%eeand38.1%eewereachievedforthehydroformylationof4-fluoro-styreneandvinylacetaterespectively.Theinfluencesofligand-to-metalratio,reactiontemperatureandthepressureofsyn-gasontheenantioselectivityandregioselectivitywerealsostudied.

简介：Twokindsofrhodiumcatalystssupportedoncross-linkedstyrene-divinylbenzenecopolymerscontainingbipyridineoro-phenylenediaminehavebeenpreparedandfoundtodisplayhighactivityformethylacetatecarbonylationtoformaceticanhydride,theactivitiesareevenhigherthantheirhomogeneouscounterparts.XPSanalysiswasusedtocharacterizethesyntheticcatalysts.TheapparentactivationparametersweredeterminedtobeEα=73.3KJ/mol,ΔH^≠=66.3KJ/mol,ΔS^≠=-28.6eu.Theseparametersareveryclosetothoseinmethanolcarbonylationandimplytohaveanalogousmechanisminbothcases.

简介：Silica-boundmercaptoselenaether-containingsilsesquioxaneanditsplat-inumorrhodiumcomplexweresynthesizedfromγ-(2,3-epithiopropyl)propyltrimethoxysi-laneviaring-openingreactionwithbis(2-hydroxyethyl)sclenide,followedbyhydrolysisandimmobilizationonfumedsilica,andthenreactingwithpotassiumchloroplatiniteorrhodiumchlorideinacetoneundernitrogenatmosphere.Itwasfoundthattwonoblemetalcomplexescancatalyzethehydrosilylationofolefinswithtriethoxysilaneeffectively.Theinfluencesoftemperature,theamountofcomplexused,thenatureofolefinoncatalyticactivitywereinvestigated.

简介：Aseriesofpolymer-supportedtetranuclearrhodiumcarbonylclustercatalystswerepreparedbthereactionofRh4（CO）12withseveralkindsofpolymersupportssuchascrosslinkedpoly（N-vinylpyrrolidone）（PNVP）andcrosslinkedpoly（styrene-co-maleicanhydride）（PMAn）,andsubsequentlywereusedtocatalyzethehydroformylationofolefins.ThecatalystswerecharacterizedbyIR,SEMandXPS.Theinfluenceofthesupportsstructureandcrosslinking,metal’scontentandparticlesizeofthesupportsonthecatalystshydroformylationpropertieswasstudied.Thefactorswhichaffectthecatalyticconversionwerealsoexamined.Theexperimentalresultsshowthatthepolymer-supportedRhclustercatalystspossessveryhighcatalyticactivityandaldehydeselectivityaswellasgoodreproducibility.

简介：ＣＡＴＡＬＹＴＩＣ　ＰＲＯＰＥＲＴＩＥＳ　ＯＦ　ＳＩＬＩＣＡ－ＳＵＰＰＯＲＴＥＤ　ＰＯＬＹ－γ－ＡＭＩＮＯＰＲＯＰＹＬＳＩＬＯＸＡＮＥ－ＲＨＯＤＩＵＭ－ＣＯＢＡＬＴ　ＢＩＭＥＴＡＬＬＩＣ　ＣＯＭＰＬＥＸ　ＦＯＲ　ＨＹＤＲＯＦＯＲＭＹＬＡＴＩＯＮＣＡＴ...

简介：LocalstructuresofthemolybdenumsulfidespeciesinthesultidedRh-Mo-K/Al2O3catalystswithvariousrhodiumloadingshavebeeninvestigatedbyXAFS.Fromthefittingresults.theMo-Mocoordinationnumberforthesamplefreeofrhodium(ca.3.7)issimilartothatforthecrystallineMoS2,indicatingthatthesupportedsulfidedmolybdenumspeciesmainlypresentaslargepatechesofMoS2-likeslabs.Fortherhodium-modifiedsamples,however,theamplitudesoftheMo-SandMo-Mocoordinationshellsaresharplyreduced,revealingahighdispersionoftheMoS2-likespeciesinthecatalysts,TheschemeofthemicrostructuresofthesulfidedmolybdenumspeciesstabilizedonthealuminasupportisdiscussedbasedupontheanalysisoftheEXAFSdata.

简介：Thesynthesisandspectrophotometricpropertiesof2-(6-methyl-2-benzothiazolylazo)-5-diethylaminophenol(MBTAE),andtheuseofitasaprecolumnderivatizingreagenttoseparateCo(Ⅱ),Ni(Ⅱ),Rh(Ⅲ)andIr(Ⅳ)complexesbyHPLCarediscussed.Whenthemobilephaseconsistsofmethanol/water(90/10Ⅴ/Ⅴ),acetatebufferwithpH4.0and5×10-5mol/LEDTAsolution,thefourcomplexesCanbeseparatedwithin9minonODScolumn.Thedetectionlimits(20μLsamplesize)are0.059ppb,0.062ppb,0.053ppband0.049ppbforCo(Ⅱ),Rh(Ⅲ),Ni(Ⅱ)andlr(Ⅳ)respectivelyatasignal-to-noiseratioof3.

简介：Theoptimalconditionsforthecomplexationreactionofmeso-tetra(3-methoxy-4-hy-droxyphenyl)porphineT(3-M-4HP)Pwithplatinumandrhodiumarepresented.Beer’sLawisobeyedwhentheconcentrationofrhodiumisintherangeof0.45-1.15μg/25mL.Themolarabsorptivityofrhodiumwasfoundtobe1.99×106L·mol-1·cm-1at460nm.ThevalueofεPtwasfoundtobe6.28×105L·mol-1·cm-1bylinearregressionmethod.TheKcoefficientmethodandcompensatingcoefficientwereusedtodetermineplatinumandrhodiumsimultaneoulywithoutremovalormaskingoftheinterferentsinthesample.Theresultsforthedeterminationofplatinumandrhodiuminthemixedsolutionofplatinumandrhodiumaresatisfactory.