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.