Collisional activation reaction of 1,2-dichloropropane has been studied at 663.2-703.2 K and at 0.04-10.0 torr.
In a carbonaceous coated vessel with allyl bromide, four isomeric chloropropenes, $CH_3CH=CH_2$ and HCl were formed. Formation of propylene and anomality of 2-chloropropene in its formation is interpreted in terms of heterogeneous reaction due to surface effect of the reaction vessel.
Whereas in the case of 1,2-dichloropropane, neat homogeneous unimolecular elimination reaction has been occurred with no propylene formation. Temperature and pressure dependences to the decomposition reaction were also studied. Collisional energy transfer by helium bath gas was found to be $300cm^{-1}$ for the stepladder and $250cm^{-1}$ for the exponential models, respectively, at 684.4 and 703.2 K. The theoretical prediction using RRKM formalism was used to compare with the experimental results and the pressure dependence of the relative ratios between rate constants was well explained by the prediction.