Mechanism and Transformation Directions of 1,1,2 - trichloroethane in the Liquid Phase by Low-voltage Electrical Discharges

Abstract

1,1,2-trichloroethane is transformed by the action of low-voltage (60 V DC) pulse discharge in the liquid medium in the nanostructure, cis-ClCH = CHCl, trans-ClCH = CHCl, CH2 = CCl2 and HCl. Conversion 1,1,2-trichloroethane 21 wt%, hydrogen chloride yield was 88.4 wt%, yield solid phase 11.6 wt%. The morphology and composition of solid phase products have been determined. According to energy dispersive X-ray spectroscopy, solid-phase products have an elemental composition, % atom: carbon — 90.5-94.2, chlorine — 1.35.4, oxygen — 3.1-4.5. The structures of 1,1-dichloroethylene and cis-, trans-1,2-dichloroethylene, as well as the isomer ratios were determined by 1H NMR. The relative content of isomers: cis-1,2-dichlorethylene 44%, trans-1,2-dichlorethylene 34%, 1,1-dichloroethylene 22%. Quantum-chemical modeling revealed the mechanism of formation of the obtained dichlorethylenes. According to the calculation results, 1,1,2-TCA is involved in the reaction in the triplet state. The difference in energy between the ground and excited states is 66.2 kcal/mol. The elimination of HCl is carried out by an activated chlorine atom generated during the transfer of 1,1,2-TCA under the action of electric discharges from the singlet state to the triplet state.