電子自旋共振經(jīng)典講座演示文稿

電子自旋共振經(jīng)典講座演示文稿本文檔共23頁(yè)；當(dāng)前第1頁(yè)；編輯于星期六\7點(diǎn)52分電子自旋共振經(jīng)典講座本文檔共23頁(yè)；當(dāng)前第2頁(yè)；編輯于星期六\7點(diǎn)52分FreeRadicalsandEPRMoleculeswithoneormoreunpairedelectronQuantummechanics:unpairedelectronshavespinandchargeandhencemagneticmomentElectronicspincanbeineitheroftwodirections(formallyupordown)ThetwospinstatesundernormalconditionsareenergeticallydegenerateEnergeticdegeneracylostwhenexposedtoanexternalmagneticfield本文檔共23頁(yè)；當(dāng)前第3頁(yè)；編輯于星期六\7點(diǎn)52分TheEPRexperimentPutsampleintoexperimentalmagneticfield(B)Irradiate(microwavefrequencies)Measureabsorbanceofradiationasf(B)Weil,Bolton,andWertz,1994,“ElectronParamagneticResonance”本文檔共23頁(yè)；當(dāng)前第4頁(yè)；編輯于星期六\7點(diǎn)52分TheEPRspectrometerElectromagnetMicrowavesourceanddetector(typicallyXband,~9.5GHz)Modulationofmagneticfieldandphase-sensitivedetectionSpectrum1stderivativeWeil,Bolton,andWertz,1994,“ElectronParamagneticResonance”本文檔共23頁(yè)；當(dāng)前第5頁(yè)；編輯于星期六\7點(diǎn)52分TheEPRspectrumA1stderivativespectrumisobtainedfromtheunpairedelectronhn=gBb0gisacharacteristicofthechemicalenvironmentoftheunpairedelectron;forfreeradicalsitisnear2.00;canvarywidelyfortransitionmetalcentersComplicated/enhancedbyhyperfineinteractionswithnucleiwithnon-zerospin本文檔共23頁(yè)；當(dāng)前第6頁(yè)；編輯于星期六\7點(diǎn)52分ThehyperfineeffectThemagneticfieldexperiencedbytheunpairedelectronisaffectedbynearbynucleiwithnon-zeronuclearspinWeil,Bolton,andWertz,1994,“ElectronParamagneticResonance”,NewYork:WileyInterscience.本文檔共23頁(yè)；當(dāng)前第7頁(yè)；編輯于星期六\7點(diǎn)52分HyperfinesplittingofEPRspectraThemagnitudeofthesplittingandthenumberoflinesdependupon:Thenuclearspinoftheinteractingnucleus#oflines=2n(I+?)soI=?gives2lines,etc.ThenucleargyromagneticratioThemagnitudeoftheinteractionbetweentheelectronicspinandthenuclearspinMagnitudeofthesplittingtypicallydecreasesgreatlywithincreasingnumbersofbondsbetweenthenucleusandunpairedelectron本文檔共23頁(yè)；當(dāng)前第8頁(yè)；編輯于星期六\7點(diǎn)52分本文檔共23頁(yè)；當(dāng)前第9頁(yè)；編輯于星期六\7點(diǎn)52分Hyperfinesplittingsareadditive本文檔共23頁(yè)；當(dāng)前第10頁(yè)；編輯于星期六\7點(diǎn)52分DirectEPRanalysisofaradicalRadicalcannotbediatomicRadicalmustbeavailableatadetectableconcentrationAtleastmetastableFrozensolutiontogreatlydecreaseradicaldecayCangreatlycomplicatethespectrumduetoanisotropyContinuousformationinsideresonatorEnzymaticradicalformationFlowexperimentRadicalcharacterizedbyhyperfineanalysis本文檔共23頁(yè)；當(dāng)前第11頁(yè)；編輯于星期六\7點(diǎn)52分DirectEPRofatyrosylradicalGunther,M.R.,Sturgeon,B.E.,andMason,R.P.,FreeRadic.Biol.Med.28:709-719,2000本文檔共23頁(yè)；當(dāng)前第12頁(yè)；編輯于星期六\7點(diǎn)52分Spintrapping:whendirectEPRisnotconvenientorpossibleUnstablefreeradicalreactswithdiamagneticmolecule(thespintrap)toformarelativelystablefreeradicalThevastmajorityofspintrapsformradicaladductsthroughtheadditionoftheradicaltothetraptoformanitroxideradical2majorclassesoftraps:nitronesandnitrosocompounds本文檔共23頁(yè)；當(dāng)前第13頁(yè)；編輯于星期六\7點(diǎn)52分AdvantagesofthenitronesReactwithavarietyofdifferentfreeradicalstoformnitroxideadductsRC.,RO.,RS.,insomecasesRN.AdductsareoftenquitestableNotterriblytoxicsoamenabletoinvivo/exvivospintrapping本文檔共23頁(yè)；當(dāng)前第14頁(yè)；編輯于星期六\7點(diǎn)52分NitronespintrapsDMPO,5,5-dimethylpyrrolineN-oxidePBN/4-POBN,phenyl-N-t-butylnitrone本文檔共23頁(yè)；當(dāng)前第15頁(yè)；編輯于星期六\7點(diǎn)52分EPRspectrafromDMPOadducts本文檔共23頁(yè)；當(dāng)前第16頁(yè)；編輯于星期六\7點(diǎn)52分EPRspectrafrom4-POBNadducts本文檔共23頁(yè)；當(dāng)前第17頁(yè)；編輯于星期六\7點(diǎn)52分NitrosospintrapsFreeradicaladdstothenitrogenatomofaC-nitrosocompound2-methyl-2-nitrosopropane,MNP3,5-dibromo-4-nitrosobenzenesulfonate本文檔共23頁(yè)；當(dāng)前第18頁(yè)；編輯于星期六\7點(diǎn)52分EPRspectrafrommethylradicaladductsofnitrosotraps本文檔共23頁(yè)；當(dāng)前第19頁(yè)；編輯于星期六\7點(diǎn)52分DMPO-trappingthetyrosylradicalOxidizetyrosinewithHRP/H2O2Gunther,M.R.,etal.,Biochem.J.330:1293-1299,1998.本文檔共23頁(yè)；當(dāng)前第20頁(yè)；編輯于星期六\7點(diǎn)52分Spintrap-derivedhyperfinefromMNPandMNP-d9EachlineintheEPRspectrafromMNPadductsisbroadenedbyhyperfinefromthe9equivalentprotonsonthespintrap本文檔共23頁(yè)；當(dāng)前第21頁(yè)；編輯于星期六\7點(diǎn)52分MNP-trappingthetyrosylradicalGunther,M.R.,etal.,Biochem.J.330:1293-1299,1998.本文檔共23頁(yè)；當(dāng)前第22頁(yè)；編輯于星期六\7點(diǎn)52分Whynotspintrap?Nitronespintraps,especiallyDMPOAdductscaninterco