物理化学学报 >> 1987, Vol. 3 >> Issue (04): 412-417.doi: 10.3866/PKU.WHXB19870415

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四氯乙烯光解活泼自由基及其与烃或醇的夺氢反应的ESR研究

刘扬; 徐广智   

  1. 中国科学院化学研究所
  • 收稿日期:1986-03-17 修回日期:1986-12-18 发布日期:1987-08-15

A STUDY OF ESR SPECTRA OF ACTIVE RADICALS GENERATED IN THE PHOTOCHEMICAL HYDROGEN ABSTRACTION REACTION BETWEEN ETHYLENE TETRACHLORIDE AND HYDROCARBON OR ALCOHOL

Liu Yang; Xu Guangzhi   

  1. Institute of Chemistry; Academia Sinica; Beijing
  • Received:1986-03-17 Revised:1986-12-18 Published:1987-08-15

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摘要： 本文用自由基捕捉剂2,3,5,6-四甲基亚硝基苯(ND)与ESR相结合的方法研究了四氯乙烯光解活泼自由基及其与烃或醇的夺氢反应, 结果表明:
1. Cl_2C=CCl_2光解首先产生Cl_2C=CCl及Cl, 而又可进一步加成为Cl_2C-CCl_3.
2. 对于CH_3(CH_2)_nOH(n=3,7)及(CH_3)_2CH(CH_2)_nOH(n=1,2)而言, Cl_2C=CCl(或Cl)分别夺取其α-碳及叔碳上的氢, 以形成CH_3(CH_2)_(n-1)CHOH及(CH_3)_2C(CH_2)_nOH, 并为ND所捕获。
3. Cl_2C=CCl(或Cl)分别夺取CH_3(CH_2)_nCH3(n=3,4,5,6), C_6H_5-CH_2CH_3及(CH_3)_2CH(CH_2)_nCH_3(n=1,4), (C_2H_5)_2CHCH_3, C_6H_5CH(CH_3)_2中亚甲基及叔碳上的氢, 以形成CH_3(CH_2)_mCH(CH_2)_(n-m-1)CH_3, C_6H_5CHCH_3及(CH_3)_2C(CH_2)_nCH_3, (C_2H_5)_2CCH_3, C_6H_5C(CH_3)_2.

Abstract: Active radicals generated during the photochemical hydrogen abstraction bet- ween ethylene tetrachloride and hydrocarbon or alcohol have been studied with the combination of ESR spectroscopy and spin trapping technique, The results show that:
1. CCl_2=CCl and Cl have been formed during the photolysis of CCl_2=CCl_2. Cl further added to C_2Cl_4 to form CCl_3-CCl_2 radical.
2. CCl_2=CCl(or Cl) abstracts hydrogen from methylene group and tertiary carbon of CH_3(CH_2)_nOH(n=3, 7), and (CH_3)_2CH(CH_2)_nOH(n=1,2), to form CH_3-(CH_2)_(n-1)CHOH and (CH_3)_2C(CH_2)_nOH respectively.
3. CCl_2=CCl (or Cl) abstracts hydrogen from methylene group and tertiary carbon of CH_3(CH_2)_nCH_3 (n=3,4,5,6), C_6H_5CH_2CH_3 and (CH_3)_2CH(CH_2)_nCH_3(n=1,4), (C_2H_5)_2CHCH_3, C_6H_5CH(CH_3)_2, to form CH_3(CH_2)_mCH(CH_2)_(n-m-1)CH_3, C_6H_5-CHCH_3 and (CH_3)_2C(CH_2)_nCH_3, (C_2H_5)_2CCH_3, C_6H_5C(CH_3)_2.