简介:CarbonsupportedPt(Pt/C)electrocatalystswerepreparedwithglucoseasprotectionagentandNaBH4asreductant.ThePtnanoparticlesdepositedoncarbonsupportpresentedreducedsizeandwelldispersityattributedtotheprotectioneffectofglucose.GlucoseabsorbedontheparticlesurfacewasreadilyremovedbywaterwashingwithoutleadingtoagglomerationofthePtnanoparticles.Theas-preparedPt/Celectrocatalystsshowedimprovedmassactivityformethanolelectrooxidationcomparedtothecatalystpreparedwithoutglucoseprotection.TheimprovedperformanceisattributedtothelargerelectrochemicalactivesurfaceareathusincreasedactivesitesonthePt/Celctrocatalystspreparedundertheprotectionofglucose.
简介:Twooxo-vanadium(IV)complexes,[VO(C2O4)(2,2′-bipy)(H2O)]·C2H5OH(1)andVO(C2O4)(phen)(H2O)(2),where2,2′-bipy=2,2′-bipyridyl,phen=1,10-phenanthroline,weresynthesizedaspotentialfunctionalmodelsofvanadiumhaloperoxidases(VHPOs)inmixedsolventofethanolandwateratroomtemperature.Thecomplexeswerecharacterizedbyelementalanalysis,infrared(IR),UV-VisandX-raycrystallography.Structuralanalysesshowedthatvanadiumatomwascoordinatedbyaterminaloxygen,oneoxygenatomfromcoordinatedwater,twooxygenatomsfromthecarboxylategroupofoxalicacid,andtwonitrogenatoms(N1andN2)from2,2′-bipy/phen.Centralvanadiumatomsincomplexes1and2werebothinadistorted-octahedralenvironment,andsomeintermolecularhydrogenbondinglinkageswerealsoobservedineachcomplex.BrominationreactionactivityofthetwocomplexeswasevaluatedwithphenolredasorganicsubstrateinthepresenceofH2O2,Br-andphosphatebuffer,indicatingthattheycanbeconsideredasapotentialfunctionalmodelofVHPO.Inaddition,thermalanalysiswasalsoperformedanddiscussedindetail.
简介:1IntroductionFullerenehasreceivedconsiderableattentionandagreatresearchinginterestduetoitsuniquestructureandinterestingproperties[1-3].Manyfunctionalgroupshavebeenintroduced,oftenregion-orstereo-selectively,fortuningthephysicalpropertiesofC60andforconstructingsupramoleculararchitectures[4-6].AmongallkindsofC60derivatives,thediseoticmolecule-substitutedC60derivativesshowinterestingproperties,especially,liquidcrystalproperties.Uptonow,fewC60derivativeswithdiscotic-moleculargroupsandtheirliquidcrystalpropertieshavebeenstudied.In1996,Deschenauxetal.[7]reportedthefirstmesomorphicC60-ferrocenederivative.Tianetal.[8]synthesizedaC60-perylenederivativein2004.Nakanishietal.[9]preparedaseriesofuncommonliquidC60derivativeswith2,4,6-tris(alkyloxy)benzalgroupsin2006.Lately,Geertsetal.[10]describedthesynthesisofmesogenicphthalocyanine-C60.
简介:Quartzcrystalmicrobalance(QCM)andcyclicvoltammetry(CV)wereusedtocharacterizethemonolayerofcytochromec(Cytc),whichwasadsorbedongoldfilmmodifiedwithalkanethiolmixedmonolayer.AdirectcomparisonofproteinsurfacecoveragescalculatedfromQCMandcyclicvoltammetricmeasurementsillustratesthattheratiooftheelectroactiveCytctothetotalsurface-confinedCytcis34%,whichsuggeststhattheorientationisamainfactoraffectingtheelectroactivityofCytc.Moreover,surfaceplasmonresonance(SPR)measurementcombinedwithCV'insitu'wasusedtoinvestigatetheconformationalchangeofCytcintheredoxprocess.Besides,Aunanoparticles(AuNPs)wereadsorbedonthesurfaceofCytc.TheresultindicatesthatAuNPspromoteelectrontransferbetweenCytcandthegoldelectrode,andSPRresultsuggestsAuNPsenhanceSPRsignal.
简介:应用分子力学、半经验量子化学RM1方法优化了32个抗野生型HIV-1病毒毒株的二芳基嘧啶类(DAPYs)化合物分子结构,从分子构象模型中提取了多种参数并结合疏水性参数与指示性参数建立QSAR多元线性回归方程.回归方程显示:分子体积V的增大会降低其抑制活性,而左苯环与嘧啶环间二面角日增大可以提高抑制活性.同时指示性参数工表明左苯环CN基团加入可以明显增加抑制活性,嘧啶环上R1位置苯基与硝基的加入可以极大降低抑制活性.