3509.     TWIGG, G. H.  Catalytic Isomerization of 1-Butene.  Proc. Roy. Soc. (London), vol. 178, 1941, A, pp. 106-117; Chem. Abs., vol. 35, 1941, p. 5775.

        Early work upon the isomerization of 1-butene to 2-butene on a Ni catalyst in the presence of H₂ is extended to D₂.  The double-bond migration is examined simultaneously with the exchange and hydrogenation reactions.  At 65°, the kinetics of double-bond migration are identical with those of hydrogenation, the rate of the reaction being proportional to the square root of the pressure of the butene or H₂.  The energies of activation are found for the temperature range 76°-126°.  At the lowest temperature, the rate of double-bond migration is 6 times that of exchange.  This is in agreement with the theory that the catalytic exchange between the olefins and D₂ takes place through the formation of an associative complex.  The step that determines the rate in the double-bond migration is the 2d fat step of the exchange reaction.  The accounts given for the double-bond migration by the dissociative theory of exchange must be regarded as inadequate; whereas the associative theory succeeds in giving a consistent picture of the whole reaction process.