Kinetic Study of Chemically Activated 1,1‐Dichlorocyclopropanes, II

Abstract

The reaction of dichlorocarbene with ethylene produces chemically activated 1,1‐dichlorocyclopropane which isomerizes in a primary reaction to give 2,3‐dichloropropene. Dichlorocarbene is generated by the thermal decomposition of CCl3 ‐ SiX3 (X = F, Cl) at 531 K. The rate constants kai of isomerization and decomposition of all chemically activated compounds reported in this work and the preceding publication were calculated by RRKM‐theory and compared with the experimental results. Agreement was obtained if an excess energy Ei for CCl2 was introduced. Ei = 9 kJ/mol for CCl3‐SiCl3 as CCl2 source and Ei = 22kJ/mol for CCl3‐SiF3 as CCl2 source. CCl2 was thermalized by addition of helium and nitrogen; the collision efficiencies of these gases were determined.