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:Three-dimensional(3D)flowerlikehierarchicalZn2GeO4andMn2+-dopedZn2GeO4microstructureshavebeenpreparedbyafacilehydrothermalapproach.X-Raydiffraction(XRD),fieldemissionscanningelectronmicro-scopy(FESEM),transmissionelectronmicroscopy(TEM)andphotoluminescence(PL)spectrometrywereemployedtocharacterizethesamples.SuchflowerlikehierarchicalZn2GeO4microstructureswithanaveragediameterof3―4μmwerefoundtobeconstructedbyabundantsinglecrystallinenanorodsofabout90nmindiameter.TheluminescentpropertiesofZn2GeO4:xMnphosphorswithdifferentcontentsofMn2+asanactivatorwereinvestigated.TheMn2+-dopedsamplesshowedgreenluminescencecorrespondingtothed-dtransitionofMn2+undertheirradiationofUVlight.Theredshift(from531nmto538nm)inλemwithincreasingMn2+contentwasobservedintheluminescentspectra,whichshouldbeattributedtoaweakcrystalfieldbecauseofthesubstitutionofZn2+byMn2+atadistortedtetrahedrallatticesite.
简介:Fe2O3/activecarbon(Fe2O3/AC)nanocompositeswerereadilyfabricatedbypyrolyzingFe3+impregnatedactivecarboninanitrogenatmosphere.Theas-preparedcompositeswerestudiedbyX-raypowderdiffraction(XRD),X-rayphotoelectronspectroscopy(XPS)andtransmissionelectronmicroscopy(TEM).Thecapacitivepropertyofthecompositeswasinvestigatedbycyclicvoltammetry(CV)andgalvanostaticcharge-dischargetest.Physicalcharacterizationsshowthattheγ-Fe2O3finegrainsdispersedintheACwell,withameansizeof21.24nm.Electrochemicaltestsin6mol/LKOHsolutionsindicatethattheas-preparednanocompositesexhibitedimprovedcapacitiveproperties.Thespecificcapacitance(SC)ofFe2O3/ACnanocompositeswasupto188.4F/gthatwasderivedfrombothelectrochemicaldouble-layercapacitanceandpseudo-capacitance,whichwas78%largerthanthatofpristineAC.AsymmetriccapacitorwithFe2O3/ACnanocompositesaselectrodeshowedanexcellentcyclingstability.TheSCwasonlyreducedbyafactorof9.2%after2000cyclesatacurrentdensityof1A/g.
简介:Asupramolecular1Dferromagneticsystemwasstudiedexperimentallyaswellastheoretically.Hybriddensityfunctionaltheory(DFT)calculationswerebasedontheX-rayanalysis.TheresultsofDFTcalculationsandMcConnellmechanismhavecontributedtotheunderstandingofthefactorsgoverningtheexchangecouplingofmagnetisminthecrystalpacking.Boththeexperimentalevidenceandtheoreticalcalculationindicatethatspindensityin2-iodonitronylnitroxide(INN)radicalsconfirms1Dferromagneticchainwithinter-chainantiferromagneticinteraction.
简介:HighlyactiveandselectiveCu/SiO2catalystsforhydrogenationofdimethyloxalate(DMO)toethyleneglycol(EG)weresuccessfullypreparedbymeansofaconvenientone-potsyntheticmethodwithtetraethoxysilane(TEOS)asthesourceofsilica.XRD,H2-TPR,SEM,TEM,XRFandN2physisorptionmeasurementswereperformedtocharacterizethetextureandstructureofCu/SiO2catalystswithdifferentcopperloadings.TheactivecomponentswerehighlydispersedonSiO2supports.Furthermore,thecoexistenceofCu0andCu+contributedalottotheexcellentperformanceofCu-TEOScatalysts.TheDMOconversionreached100%andtheEGselectivityreached95%at498Kand2MPawithahighliquidhourlyspacevelocityoverthe27-Cu-TEOScatalystwithanactualcopperloadingof19.0%(massfraction).
简介:基于密度泛函理论(DFT)的第一性原理平面波超软赝势方法,计算了纯MgF2晶体、Co掺杂MgF2晶体、P掺杂MgF2晶体和(Co,P)双掺杂MgF2晶体的电子结构和光学特性.结果表明,掺杂后的MgF2晶体发生了畸变,原子之间的键长也有所变化.(Co,P)双掺杂后,由于非金属原子P态和金属原子d态之间的轨道杂化,在MgF:的导带与价带之间形成了新的杂质能级,这些杂质能级一方面减小了MgF2的带隙宽度,使光吸收曲线红移到可见光区,另一方面有利于光生电子一空穴对的分离,提高了MgF2光催化效率.(Co,P)双掺杂使位于禁带中的杂质能级的态密度明显增加,导致电子从价带跃迁到杂质能级和从杂质能级跃迁到导带的概率增加,从而使其对太阳能的利用率提高.并揭示了(Co,P)双掺杂MgF2在光学元器件方面的潜在应用.
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.
简介:Aseriesofnovel1H-benzimidazol-1-ylacetatesand1H-benzimidazol-1-ylpropionatescontaining1H-1,2,4-triazolemoietyweresynthesizedundermicrowaveirradiationbymulti-stepreactions,inyieldsof87-94%.TheirinvitroantifungalactivitiesagainstBotrytiscinereaandSclerotiniasclerotiorumwereevaluatedbymycelialgrowthratemethod.AllthetargetcompoundsexhibithighactivitiesagainstB.cinereawiththeEC50valuesof7.96-21.74μg/mL,higherthanthatofcarbendazim.
简介:Poly(4-vinylpyridine)supportednanoparticleofcopper(Ⅰ)iodideisreportedasagreenandrecyclablecatalystfortheregioselectivesynthesisof1,4-disubstituted-1H-1,2,3-triazolesfrombenzylhalides,sodiumazideandterminalalkynesinwater.Thiscatalystcanberecoveredbysimplefiltrationandrecycledupto8consecutiverunswithoutanylossofitsefficiency.