Stable products and radicals in the radiolysis of dichloromethane and 1,1,-dichloroethane gamma-irradiated in an oxygen-free atmosphere

Abstract

Stable and transient products of the γ-radiolysis of dichloromethane (DCM) and 1,1-dichloroethane (11 DCE) have been investigated in an oxygen-free atmosphere. The stable products were separated by preparative gas chromatography and identified by NMR and mass spectroscopy. The quantitative determinations were performed by potentiometric and gas chromatographic analysis. The main products of radiolysis of DCM are dimers (11DCE, 12DCE, 112TCE, 1122TetraCE) and the product of dechlorination CM; in the case of 11DCE-dimers (133TCB, 2233TetraCB) and the product of dechlorination CE as well as products of isomerization and chlorination of the parent compound (12DCE, 112TCE). The gas products of both chlorides are HCl and H2. The ESR investigations at 77 K indicate the formation of at least two kinds of radicals in both chlorides: CH2Cl/CHCl2=1/3 in DCM and CH3CCl2/CH3CHCl=2.5/1 in 11DCE. An outline of the mechanism of radiolysis is proposed.