西南林大现代生化仪器分析课件08质谱分析第3节 有机分子裂解类型与过程

10:34:48第八章质谱分析一、有机分子的裂解cleavagetypesoforganicmolecular二、σ―断裂σ-cleavage三、α―断裂α―cleavage四、重排断裂rearrangementcleavage第三节有机分子裂解类型massspectrometry，MScleavagetypesoforganiccompounds10:34:48一、有机分子的裂解当有机化合物蒸气分子进入离子源受到电子轰击时，按下列方式形成各种类型离子（分子碎片）：ABCD+e-ABCD++2e-分子离子BCD•+A+B•+A+CD•+AB+A•+B+ABCD+D•+C+AB•+CD+C•+D+碎片离子10:34:48二、σ―断裂σ-cleavageABBA+H3CCH2CH2CH2CH2CH315712957434357297115H3CCH2CH2CH2CH2CH3H3CCH2CH2CH2CH2CH3H3CCH2CH2CH2CH2CH3H3CCH2CH2CH2CH2CH3CH3CH2CH2CH2CH2CH31529435771正己烷10:34:48三、α―断裂BAZAZ+BRCH2OHRCH2OH+RCH2OR'RCH2OR'+RCH2NR'2RCH2NR'2+RCH2SR'RCH2SR'+10:34:48H3CCH2CH2CHCH3OHCHCH3OHH3CCH2CH2m/z=45(M-43)H3CCH2CH2CCH3OHHm/z=87(M-1)H3CCH2CH2CHOHCH3m/z=73(M-15)m/z203040506080907045(M-43)55[M-(H2O+CH3)]73(M-CH3)88(M)M-170(M-H2O)α―断裂——丢失最大烃基的可能性最大丢失最大烃基原则10:34:4820304050607080901004357m/z100(M)712972H2CCCH2OCH2H3CCH3H2CCOH3C[CH2CH2CH3]-m/z=57(75%)CCH2OCH2CH3H2C][H3C-m/z=71(48%)H2CCCH2OCH2H3CCH310:34:4810:34:4820304050607080901002945m/z11027735987102(M)OCH2CH3HCH2CCH3H3CCH3OCH2CH3HCCH3CH2CH3OCH2HCH2CCH3H3Cm/z=73m/z=8710:34:48—开裂RCH2CHH2CRCH2CHH2CR'CH2CHHCRR'CH2CHHCRR'CH2CHHCRCH2RRCH2m/z=91m/z=91m/z=39HC扩环苄基离子卓鎓离子HCHCHCm/z=6510:34:48CHCHCHCZHR1R2R3R4CHCHR3R4HCCZHR1R2麦氏重排麦氏重排条件：·含有C=O，C=N，C=S及碳碳双键·与双键相连的链上有碳，并在碳有H原子（氢）·六圆环过度，H转移到杂原子上，同时键发生断裂，生成一个中性分子和一个自由基阳离子四、重排断裂10:34:48分子碎片重排后再次裂解：10:34:48204050607080901004357m/z1007129120130110128(M)30858658COCH2H2CCH2CH2CH3H2CH3C5785437110:34:48COCH2H2CCH2CHH2CH3CCH3HCOHCH2H2CH2CCH2CH2CHCH3HCOHCH3CH2H2CCH2m/z=86m/z=5810:34:48COCH2CH2CH2CHH2CH2CCH3HCOHCH2H2CCHCH2CH3CHCH2COHCH2H3CH2CCH2m/z=100m/z=58HHCH310:34:48CH2COCH2OCH2HH2CH2CHH2CCOCH2OHCH2HH2CCOOHH2CCH2HCH2CH2H3CCOOHH2CCOHOHCH2H2Cm/z=88m/z=88m/z=60