The Rh-BIPHEPHOS catalyzed double bond isomerization of 1-decene as representative substrate for the hydroformylation of long-chain olefins was investigated. To obtain information about the thermodynamic equilibrium between the possible isomers of 1-decene, including all individual cis/trans isomers, calculations based on Gibbs energy minimization were performed and experimentally validated. The necessary thermodynamic properties of formation were calculated using Benson's group increment theory (BGIT) method. Kinetic validation experiments were performed with 1-decene in two different solvents (DMF, toluene) to evaluate solvent polarity effects on the concentration courses. The experimentally determined equilibrium isomer composition was in very good agreement with the predictions. Thus, reaction isomerization equilibrium constants can be predicted reliably based on the applied method and can be used in subsequent kinetic investigations. (C) 2014 Elsevier B.V. All rights reserved.