THE SECONDARY HYDROGEN ISOTOPE EFFECTS IN THE PYROLYSIS OF ETHYL-d5 ACETATE AND ETHYL ACETATE-d3

Abstract

Rate constant expressions have been obtained for ethyl acetate and ethyl-d5 acetate in the temperature ranges 500–603 °C and 501–614 °C.[Formula: see text]By measuring the relative rate of production of C2H4 and C2D4 from identical mixtures of the two esters at the temperatures 387 and 490 °C, it has been possible to determine the temperature coefficient of the relative rate constant more accurately. This, coupled with the relative rate constants at 500 °C derived from the above equations, gives the relative rate constant expression.[Formula: see text]These data are compared with the intramolecular isotope effect in the decomposition of ethyl-1,1,2,2-d4 acetate, and the differences attributed to secondary isotope effects.The rate of decomposition of ethyl acetate-d3 was found to be identical within experimental error with that of the normal acetate.