Rate constants for reactions of Cl abstraction from CCl_4 by CCI_3CH_2.CHR radicals and Br abstraction from CCI_3CH_2CHBrR(R=Bu~n,AcO,OCNC_4H_8,CN) by ~.Re(CO)_5 radicals

摘要

The rate constants for reactions of Cl abstratction from CCl_4 by CCI_3CH_2.CHR radicals and Br abstraction from CCI_3CH_2CHBrR (R=Bu~n,AcO,OCNC_4H_8,CN) by ~.Re(CO)_5 radicals were determined by ESR spectroscopy using spin trapping technique. Replacement of H atoms at the C(#beta#) atom by O or N atoms reduces the reactivity of the radicals in the reactions of Cl abstraction from CCl_4 by approximately an order of magnitude. THe presence of two polar groups at the C(#beta#) atom results in appreciable decrease in the strength of the C-Br bond in CCI_3CH_2CHBrR adducts.