A STUDY OF THE KINETICS OF REACTION OF FE(CO)3 AND FE(CO)3(L) WITH H-2 AND C2H4 FOR L = H-2 AND C2H4 BY TRANSIENT INFRARED-SPECTROSCOPY - REACTIONS RELEVANT TO OLEFIN HYDROGENATION KINETICS

The reactions of Fe(CO)3 with ethylene and H-2 have been studied and rate constants for the formation of the H2Fe(CO)3 and Fe(CO)3(ethylene) complexes have been obtained. Further reactions of these unsaturated products with ethylene and H-2 respectively have been shown to lead to formation of the H2Fe(CO)3(ethylene) complex which is a crucial intermediate in the proposed mechanism for Fe(CO)3-induced hydrogenation of ethylene. The rate constants for formation of this complex from both precursors have been obtained and are reported along with the other rate constants determined in this study. Interestingly, though ethane is produced on a long time scale under the experimental conditions, H2Fe(CO)3(ethylene) is stable at room temperature in the approximately 100-mu-s observation time of these experiments. Significant differences have been observed for the rate constants of formation of the various complexes that were studied. These variations are discussed with respect to spin allowed versus disallowed reactions and the nature of the reacting ligand.