SURFACE-CATALYZED HYDROCHLORINATION OF ALKENES - THE REACTION OF THE GASES HYDROGEN-CHLORIDE AND 1,3-BUTADIENE

Mixtures of gaseous hydrogen chloride and gaseous 1,3-butadiene at total pressures less than 1 atm and at temperatures between 294 and 334 K yield mixtures of 3-chloro-1-butene and (E)- and (Z)-1-chloro-2-butene. The ratio of the product of putative 1,2-addition to those of 1,4-addition is approximately unity with only the amount of (Z)-1-chloro-2-butene increasing from ca. 2% of the total reaction product mixture at the lower temperature to ca. 4% at the higher temperature. Kinetic measurements have been made by observing the reaction throughout its course utilizing FT-IR spectroscopy. It is concluded that surface catalysis is required for product formation and that the reaction, which occurs at the walls, is most probably between multilayer adsorbed hydrogen chloride and gaseous or weakly adsorbed 1,3-butadiene.