A Novel Laser-Induced Synthesis of 1,1 -Dichloroethylene from 1,1 -Dichloroethane

摘要

References(20) As a new photochemical process for synthesizing 1,1-dichloroethylene (VC) from 1,1-dichloroethane (1,1-DCE), the laser-induced photochlorination of 1,1-DCE followed by its dehydrochlorination has been examined with excimer laser irradiation in a flow reactor under normal pressure and 298–623 K.In the laser-induced photochlorination of 1,1-DCE, a high selectivity for 1,1,1-trichloroethane (1,1,1-TCE), which was expected to yield VC uniquely in the following dehydrochlorination stage, was obtained in the lower temperature range. In the laser-induced photodehydrochlorination of 1,1,1-TCE, a small amount of Cl2 addition promoted the formation of VC, and the yield of VC was strongly dependent on the Cl2/1,1,1-TCE ration and the reaction temperature. By experimental work and kinetics study, both of these reactions are thought to proceed by a chain mechanism.By connecting two reaction cells in series, in which the above two reactions are individually carried out, a new photochemical process for synthesizing VC from 1,1-DCE was designed. In this system, experimental results suggested that two factors, the complete consumption of substrate in the first cell and the addition of Cl2 before the second cell, are important for attaining a higher selectivity for the desired product.