A comparative investigation on the isomerization reactions of 1-alkenes to their corresponding 2-alkenes catalyzed Ru3(CO)12 (1), Ru3(CO)9(PEt3)3 (2) and Ru3(CO)10(dppe) (3), (where dppe = 1,2-bis(diphenylphosphino)ethane) is described. Both the complexes of types 2 and 3 were characterized by all analytical and spectroscopic data. The molecular structure of 2 was confirmed by single-crystal X-ray analysis. It is observed that the nature of phosphine ligands plays an important role in the isomerization of 1-alkenes. When the chelated diphosphine is used, the internal isomerization reaction by [Ru3(CO)10(dppe)] (3) is completed relatively in less time compared to other derivatives. As per the DFT calculations, the observed reaction rate for the alkene isomerization may be explained based on the relative stability of 1, 2, and 3. The CO abstraction step is highly feasible in 3, the least stable among the three, thus the reaction occurs at the highest rate. Due to the increased relative stability from 2 to 1, the reaction requires more time at elevated temperatures and the rate decreases as a consequence. © 2020 Elsevier B.V.