Thermodynamics of the geometrical isomerization of 2-butene and 2-pentene

Abstract

The use of two different catalysts for the metathesis of alkenes, active in adjoining temperature regions, allowed an accurate determination of the equilibrium constant for the gas-phase cis-trans isomerization of both 2-butene and 2-pentene over the temperature range 250 to 823 K. Because of this broad temperature range, thermodynamic functions of these reactions, viz. ΔGo(g, T), ΔHo(g, T), ΔSo(g, T), and even ΔCpo(g, T), could be evaluated with a higher precision than from thermochemical tables (API, NBS) or from other equilibrium studies. Moreover, the use of recent spectroscopic quantities for 2-butene results in calculated values of thermodynamic functions which are more in agreement with our experimental results than the values in the API tables. © 1983.