电子顺磁共振波谱仪EPR的基本原理和基本应用

电子顺磁共振波谱仪（EPR）的基本原理和基本应用姚加2016.3.10内容原理仪器应用EPR/ESR/EMREPR:ElectronparamagneticresonanceESR:ElectronspinresonanceEMR:ElectronmagneticresonanceESREPRESREPREPREPR……/各种活性物质：(a)Oxygen-CenteredRadicals(Reactiveoxygenspecies,ROS):O2-•,•OH,H2O2,LO•,LOO•,LOOH…(b)Sulfur-CenteredRadicals:•SH,LS•,…(c)Nitrogen-CenteredRadicals(Reactivenitrogenspecies,RNS):NO,ONOO/ONOOH(过氧亚硝酸),…(d)Carbon-CenteredRadicals:R•,…(e)……它们大多化学性质活泼、不稳定性、寿命短，极易引发其他连锁反应……通过自旋捕获技术，研究自由基的生物和化学过程。34803490350035103520353035403550MagneticfieldR•RO•HO•HOO•ROO•/O2–14N(I=1)2nI+1=9JournalofMagneticResonance171(2004)80–89=515N(I=1/2)2nI+1=5……Zn1+4s1Zn-ZSM-5COCH4CO2CH3OHO2Chem.Sci.,2012,3,2932–2940J.Am.Chem.Soc.2013,135,6762−6765O2CO100nm350nm1umT=4KEPRg~2.08g~4.4g~2.08EPRDysonianshape《Electronspinresonance-Acomprehensivetreatiseonexperimentaltechniques》2nd1983∝ΔN=Nβ–NαNα/Nβ=exp(‒ΔE/kT)Zeemaneffect磁场对谱线的裂分•μL=−gLμBLLgL=1μe=−geμBSS=½ge=2.002319gμL=−gLμBLμe=−geμBS—μS=−geμBSB0H0E=geμBB0MS(MS=-S,-S+1,…,S)EPRGunn波段频率范围/GHz代表性频率/GHz代表性磁场/mTL0.390～1.5501.554S1.550～3.9003.0110C3.900～6.2006.0220X6.200～10.9009.5340K10.900～36.00023820Q36.000～46.000361300V46.000～56.000501800W56.000～100.000953400传统微波波段的频带宽度以及g＝2的磁场flatcellL:~cmX:1mmW:0.1mmFe3+,3d5高频小振幅调制信号示意图含一个未偶电子和一个12I=核（即氢原子）体系的能级分裂示意图2nI+1N中心捕获剂的自由基加成反应DMPO捕获剂如何辨别自由基的种类？34803490350035103520353035403550MagneticfieldR•RO•HO•HOO•ROO•/O2–ZZZZ3d7Fe1+,Co2+,Ni3+3d9,Ni1+3d7,Ni3+gzz=g∥gxx=gyy=g⊥gzz=g∥gxx=gyy=g⊥3d7,Ni3+Thanksforyourattention!