简介:ThesemiconductingpropertiesofanodicfilmformedonPbin4.5mol.dm-3H2SO4solu-tion(30℃)at0.9V(vs.Hg/Hg2SO4)for2hwerestudiedusingACimpedancemethod.ThephasecompositionofthefilmisPbSO4andPbO.PbSO4.Thesemiconductingpropertiesareduetothelatter.TheMott-Schottkyplotsshowthatthesaidfilmisann-typesemiconductorwithflat-bandpotentialof-0.9V(vs.Hg/Hg2SO4)anddonordensityof1×1016cm-3.Thesurfacedensitymeasuredat410—2500Hzis(2—5)×1012cm-2eV-1.
简介:Electroactiveself-assembledmonolayers(SAMs)containingviologeugroupareformedthroughtheadsorptionofthiol-functionalizedviologencompoundCH3(CH2)9V2+(CH2)8SH,whereV2+isN,N’-diaIkylbipyridinium(i.e.aviologengroup),ontogoldelectrodesfrommethanol/watersolutionanditselectrochemicalbehaviorisinvestigatedbyAcvoltammetryandsquarewavevoltam-metry,whichhavethehighsensitivityagainstbackgroundcharging.TheviologenSAMformedisasub-monolayerandthenormalpotentialscorrespondingtothetwosuccessiveone-electrontransferprocessesoftheactivecenters(viologen)are-360mVand-750mV(vs.Ag/AgCl)in0.1mol/Lphosphatebuffersolutions(pH6.96)respectively,andthestandardelectrontransferrateconstantis9.0s-1TheelectrochemicalbehaviorofthisSAMinvarioussolutionshasbeenpreliminarilydiscussed.
简介:Analternativerouteforthesynthesisof(-)-10-epi-ct-cyperone1startingfrom(+)-dihydrocarvone2isdescribedbyusinganasymmetricMichaeladditionasakeystep.Theroutefeaturesmoreefficientlyandcanbeperformedinlargescale.
简介:Theefficientcycloadditionreactionswerecarriedouttoaffordthenovel3,5-disubstituted-dihydroisoxazolesfrommethylundec-10-enoateandisoxazoles,triazoleandtetrazolo-triazolefrommethylundec-10-ynoate.Thereactionsoccurredunderrelativelymildconditionsandaffordedthedesiredproductsingoodyields.
简介:Threenewlanthanidephenoxyacetatecomplexeswith1,10-phenanthroline,[Nd(POA)3(phen)]2·2C2H5OH(1),[Eu(POA)3-(phen)]2·2C2H5OH(2)and[Sm(POA)2(DMSO)(phen)]2-(ClO4)2(3)(POA=phenoxyacetate,phen=1,10-phenanthroline,DMSO=dimethylsulfoxide),weresynthesizedandcharacterizedbyelementalanalyses,IR,UV-visandFAB-MSspectra.TheirstructuresweredeterminedbysinglecrystalX-raydiffractionanalysis.Incomplexes1and2,thecarboxlyategroupsarebondedtoLn^3+ioninthreemodes:thechelatingbidentate,thebridgingbidentateandthebridgingtridentate.Incomplex3,thecarboxylategroupsarebondedtoSm^3+iononlyinvolvedinonemode:thebridgingbidentate.Theluminescencebehaviorofcomplex2wasalsostudiedbymeansofemissionspectra.
简介:Twenty10-hydrocarbylacridonesand2-methylacridone,1-hydroxyacridoneweresynthesizedfromacridoneandcharacterizedbymp,IR,UV,1HNMRandMS.UsingNd:YAGasalasersource,thesecond-orderharmonicgeneration(SHG)valuesoftheacridonederivativesweremeasuredinpowderstateascomparedwithureapowder.TheresultsshowedthattheSHGvaluesofsomeof10-hydrocarbylacridoneswerehigherthanthatofurea,whileotherswerelower.Althoughthehydrocarbylsubstituents(R)attachedtonitrogenatomofacridoneweredifferentinsizeandelectronegativity,theyhadalittleeffectontheSHGvaluesof10-hydrocarbylacridones.Substituents,suchasmethylorhydroxygroupconnectedtothephenylring,causedalittleeffectontheSHGvalues,too,comparedwithacridone.TheabilityofRtopushelectrontowardthenitrogenatomortopullelectronfromthenitrogenatomplayanimportantroleonthemaximumwavelengthesofUV-visibleabsorptionofacridonederivatives.
简介:目前,国内没有关于半钢发热剂的国家标准检测方法,只能根据组分范围分别检测各个组分,不仅耗时而且使用的大量化学试剂对环境造成污染。故研究了X-射线荧光光谱法快速测定半钢发热剂中Si,P,S的方法。采用粉末压片制样,研究其制样条件,包括磨样时间、压样时间和压力对测定结果的影响。采用其它方法定值提供的检测样品,作为x-射线荧光光谱法内控标准样品,采用经验系数法进行基体校正,通过解谱拟合建立校准曲线,校准曲线建立后仪器建立漂移校正程序。实验结果精密度好,各元素的相对标准偏差在0.15%-1.3%。准确度满足生产需求,实验方法可用于快速检测半钢发热剂化学组分。
简介:针对多种类不锈钢多元素成分解析问题,应用X射线荧光光谱分析软件UniQuant,采用扩展基本参数法对多元不锈钢、双相不锈钢进行光谱干扰校正和基体校正,重新设定和优化多元不锈钢基体元素的测试条件,计算背景因子、杂质因子、谱线灵敏度系数和光谱重叠系数,测定Si、Mn、S、P、Ni、Cr、Cu、Mo、V、Al、Ti、Nb、Co、Ta、Fe的相对标准偏差在0.04%-3.8%,Ca、Zr、W、As、Sb、Sn的相对标准偏差在5.4%-20.3%,未知样品检测值与认定值比对结果相当理想,Ni、Cr的平均偏差小于0.05%,可以用很少标准样品实现各类型不锈钢多元素成分准确检测,检测范围宽,适用性好。
简介:利用水热合成方法合成了2个新的配位聚合物[Ag(4,4′-bpy)(H2PO4)].2H2O(1)和[Cu4(L)8H4](2)(4,4′-bpy=4,4′-联吡啶,L=4-咪唑基苯甲酸),并通过元素分析、红外光谱和X-射线单晶衍射方法确定了该化合物的晶体结构.结构分析表明化合物1属于单斜晶系,P2/c空间群,晶胞参数a=8.4909(17)nm,b=8.7284(17)nm,c=18.498(4)nm,β=100.99(3)°,V=1.3458(5)nm3,Z=4,R1=0.0362,ωR2=0.0966.化合物1展示了一个一维的链式结构.化合物2属于单斜晶系,C2/c空间群,晶胞参数a=24.509(5)nm,b=18.957(5)nm,c=17.246(5)nm,β=119.807(5)°,V=6.953(3)nm3,Z=4,R1=0.0455(3564),ωR2=0.1519(6161).化合物2中存在着丰富的π…π堆积作用.
简介:Thesynthesisofanewtypeofhetero-macrocyclicpolyether2,3-henzo-1,4,7,13-tetraoxa-10-selenacyclopentadeca-2-eneisdeseribed.
简介:Halfsandwichirondicarbonylcomplex[η5-C5H3(t-Bu)2]Fe(CO)2Cl(1)reactswith1,2-dilithiumdiselenocarboraneLi2Se2C2B10H10(2)togiveabinuclearironcarboranecomplex[η5-C5H3(t-Bu)2]2Fe2(CO)3*Se2C2B10H10(3).TheX-raydiffractionanalysisofcomplex3revealsthatoneoftheironatomsischiral.